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The dangers of mercury

 

You’ve most probably heard that mercury is a dangerous substance if you get exposed to it. If you’ve ever wanted to know more about this topic, then this article comes at the right time.

Before getting into what the dangers of mercury are, let’s take a moment and talk about it in general and what the potential sources of contamination are since there might be some things that could use some clarifications.

Mercury is a naturally occurring element

Mercury is part of what nature gave us by default and it exists in the air, water, and soil. It occurs naturally in our planet’s crust and it’s released into the environment through volcanic activity.

However, human activity is one of the leading causes of mercury releases, through coal-fired power stations, coal burning for residential heating and cooking, waste incinerators, other industrial processes, as well as mining for gold, mercury, and other metals.

There are several types of this substance you can encounter, as these are: elemental (or what is known as metallic), inorganic (through occupational exposure), and organic (to which we are exposed through food). Of course, all of these forms have different degrees of toxicity and effects on health.  

 

How you can get exposed

The story goes like this. The mercury is released into the environment, and from there it can be transformed into methylmercury through bacteria. Methylmercury is the organic form that we can ingest through our diet, and it’s toxic.

Then another process takes place which is called bioaccumulation and which occurs when an organism contains higher concentrations of a certain substance than its surroundings. Methylmercury bioaccumulates in fish and shellfish.

However, this is not the end of the story, as this process goes further and biomagnifies since nature follows its course. Large predatory fish eat the smaller ones, and the result is that they are more likely to ingest, and therefore contain, higher levels of mercury. Smaller fish also acquire some mercury by ingesting plankton.

As stated above, people can be exposed to various types of mercury, depending on the circumstances. However, the main contamination occurs by eating fish and shellfish containing high levels of the substance. Unfortunately, cooking the food does not eliminate mercury; therefore it’s not a solution in this case.

Another main source is occupational, as workers can inhale elemental mercury vapors created by industrial processes.

Sensitive groups

Two types of people are more commonly sensitive to the effects of mercury. The first ones are fetuses, and they are the most susceptible to developmental issues.

If a fetus is exposed to methylmercury in the womb, which can occur due to the mother’s consumption of fish and shellfish, the baby’s brain and nervous system can be affected. The substance’s primary health effect is an impaired neurological development.

Cognitive thinking, attention, language, memory, and fine motor and visual spatial skills can be affected for those children who have been exposed to methylmercury as fetuses.

The second group that is sensitive consists of those people who are regularly exposed to high levels of the substance. Chronic exposure can occur in populations that rely on fishing to survive or for people who are occupationally exposed.

When it comes to fishing populations, studies have shown that between 1.5/1000 and 17/1000 children developed cognitive impairment caused by the consumption of fish that contained mercury. These numbers applied to countries such as Brazil, Canada, Columbia, China, and Greenland.

 

Mercury exposure health effects

Both elemental and methylmercury are toxic and can affect the central and peripheral nervous systems. Inhaling mercury vapors can have harmful effects on the immune, digestive and immune systems, as well as on kidneys and lungs.

The inorganic salts of mercury are corrosive and can affect the eyes, skin, and gastrointestinal tract. They can also lead to kidney toxicity if ingested.

After a significant exposure either through ingestion, inhalation or through the skin, neurological and behavioral disorders can be observed. These symptoms include headaches, memory loss, cognitive and motor dysfunctions, tremors, or insomnia.

 

The type of exposure matters

Right now it seems like the unthinkable, but doctors in the late 19th century were giving patients significant amounts of mercury to drink in order to treat intestinal obstructions.

Although this is by no means advisable, it does lead to the understanding that there’s a significant difference between drinking mercury or being exposed to vapors. Inhalation is more damaging because the invisible particles get straight into the lungs, and from there into the blood system.

Effects on fertility

Recent studies have shown a correlation between high levels of mercury contained in the body through seafood consumption, and otherwise unexplainable infertility phenomena in women or abnormal analysis results in men.

To prevent all of these effects, you can follow the recommendations made by the U.S. Environmental Protection Agency and the Food and Drug Administration on which types of fish and seafood are least contaminated and try eating only those.

 

Prevention measures

Of course, you might be wondering what can you do to avoid getting exposed to this substance. One thing would be to identify all the potential sources that might be right now in your home and make sure they are safely kept.

For example, older underarm thermometers contain mercury in liquid form that, if the instrument gets broken, is potentially dangerous since it vaporizes at room temperature. When that happens, the air is filled with invisible particles that can quickly be absorbed by the body.

The vaporization process takes longer in the case of mercury, so if it gets into cracks and corners and is left there, you can be exposed for days, weeks, or even longer periods.

Another obvious thing to do is to avoid eating seafood during pregnancy, to prevent any contamination that might reach the womb. Once the baby is born, you might want to look into getting one of those safe and useful pediatric thermometers to prevent any type of unfortunate events.

If you suspect any contamination, you should see your doctor, take all the necessary tests, and then, if needed, undergo a dedicated protocol to cleanse your body from it.

 

 

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Science most definitely has a beautiful side, too, and the Galileo thermometer is one of the instruments that translate the exactitude of scientific observations and principles to useful objects that adorn any interior space.

Before taking a look at what a Galileo thermometer is, let’s take a moment and talk about the well-known scientist whose name it is carrying.

Who was Galileo Galilei

Born in Italy in 1564, Galileo Galilei was an astronomer, engineer, physicist, philosopher, and mathematician whose work greatly influenced many of the principles known at the time and altered the course of scientific research and knowledge towards modernity.

Although some of his findings were controversial during his lifetime, they were, of course, correct, thus setting a new path for science. His most notable work that was regarded as highly controversial was on heliocentrism and Copernicanism, which placed the sun at the center of the Solar System.

During his lifetime he was tried by the Inquisition, found suspect of heresy, and forced to recant. Galileo Galilei spent the rest of his days under house arrest. However, during this period he wrote some of his best-known works on kinematics and strength of materials.

He was also the one who discovered that the density of liquid changes as a result of increasing and decreasing temperatures, which, evidently, leads us to our topic, the Galileo thermometer.

 

The true inventors

Although you would expect that this thermometer was invented by the famous scientist, funnily enough, that is not actually the case. Galileo Galilei did invent an air thermometer, better known as a thermoscope, around 1603, but it was not this one.

What we call today the Galileo thermometer was, in fact, invented by a group of academicians and technicians known as the Accademia del Cimento of Florence. It’s true that this group included Galileo’s pupil, Torricelli and Torricelli’s pupil Viviani, but that is pretty much the only connection between the instrument and Galilei himself.

The writings of the time described the device as slow and lazy, and this is accurate, since it uses the changing density of liquids and the principle of buoyancy to measure the outside temperature. Buoyancy determines whether an object floats or sinks in a liquid, this way explaining how ships made of steel float in the water.

It’s actually pretty hard to find another more beautiful way to measure the temperature than this device, although it’s true that the readings are fairly accurate and not as good as those provided by a regular thermometer.

How it’s made

Manufactured since the end of the 17th century, the Galilean thermometer is made up of a sealed glass cylinder, and inside there’s a transparent liquid and a series of bulbs that also carry an attached weight.

Each one of the weights attached to a bulb is also tagged with an engraved number and a degree symbol. When it comes to the weights, they are actually calibrated counterweights and each one is different from the others.

Another particularity that makes this measuring instrument very appealing is the different coloring of each bulb. This is added so that all the liquids involved have the same density, but it’s also the element that adds an overall attraction of what is most definitely a very special thermometer.

 

How it works

You might remember from your science class that an object immersed in a fluid experiences two different forces: gravity which is pulling it downward and buoyancy which is pushing it upward. In the case of this thermometer, the force of gravity is the one that makes it work.

Besides being a beautiful object by itself, the Galileo thermometer uses the bulbs to read temperatures, as they rise and fall depending on these principles. The basic idea is that, as the temperature of the air changes, it transfers to the temperature of the liquid surrounding the bulbs which, as a result, changes its density.

Each bulb has the same volume and the same density, therefore the same magnitude of gravitational and buoyant forces act upon it at any given moment. However, each of these bulbs is also defined by the mass suspended from its base which increases the relative weight of the bulb.

This means that the effect of gravity is also altered compared to the other ones. As the density of the surrounding fluid changes, the force of gravity manages to overcome the buoyant force, thus making the bulbs sink or float. The principle is that as density decreases, the buoyant force does the same.

The temperature of each bulb remains constant so that as the temperature of the surrounding fluid increases, its density decreases. Since the buoyant force follows in the same way, the gravity continues to pull downwards and makes the bulb sink.

How to read a Galileo thermometer

At any given point, some of the bubbles float while others sink, and the one that sinks the most actually indicates the approximate temperature of the surroundings.

A small Galileo thermometer can have 6 degrees Fahrenheit of difference between the bulbs, which means that there’s enough room for errors. Most models cover temperatures between 68 and 84 degrees Fahrenheit which means they are suitable only for indoor spaces that are heated or air conditioned.

In order to read a Galileo thermometer all you have to do is to look at the lowest bulb that is floating and ignore the ones that are touching the bottom of the container. The bulbs that are neutrally buoyant that show the ambient temperature.

If there’s no bulb floating in the gap formed by the sunken and the rising bulbs, simply use the lowest bulb from the floating cluster to read the temperature. This thermometer is certainly not the most precise alternative, but it’s a very clever way to showcase some basic physics principles and have a beautiful object around the house.

If you would like to read about more precise measuring alternatives, you can check out our other articles on topics such as finding an effective infrared thermometer or finding out how an instant thermometer can help you out in your everyday life.

 

 

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Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.

If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.

How it gets released

Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.

First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.

Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.

Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.

 

Types of mercury

This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.

Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.

Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.

All of these forms have different degrees of toxicity and effects on the human body.

How methylmercury is formed

The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.

As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.

 

Exposure to mercury

On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.

Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.

Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.

The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.

In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.

Exposure effect on humans and animals

Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.

Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.

After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.

Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.

 

Preventive measures

Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.

Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.

If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.

Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.

 

 

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We use this term almost every day, but do we really know what’s behind it? The notion of temperature is related to many different things and there’s an entire science behind it. Besides that, there are many cool facts related to temperature that you might not be aware of but that are part of our lives.

In this article, we’ll take a look at only some of them since covering everything like an impossible task. However, here you’ll find seven facts about temperature in general that will make you think about it differently the next time you’ll wonder what to wear if it’s cold or warm outside.

The science behind temperature

Temperature is a measurement of heat energy that expresses how hot or cold something is. Given its usability, this measurement has a significant part in all fields of natural science, including Earth science, physics, chemistry, biology, and medicine.

Different measurement units have been developed to express temperature, the best known ones being the Celsius, Fahrenheit and Kelvin scales. The speed of the molecules is what determines the temperature of a substance. The faster this speed, the hotter the substance.

Another interesting aspect related to temperature regards the boiling point of water (an essential reference point for this topic), which is correlated to and depends on the atmospheric pressure.

Therefore, at sea level water boils at 212 degrees Fahrenheit, in Tiber water boils at 188.6 degrees Fahrenheit, while at the top of Mount Everest the boiling point is at 159.8 degrees Fahrenheit.

 

Hottest human-made temperature

We managed to achieve right here, on Earth, a temperature that is roughly 250,000 times hotter than the core of the sun. In case you are wondering what this would look like in figures, well here’s the answer – the hottest human-made temperature ever recorded is 7.2 trillion degrees Fahrenheit.

This outstanding recording has been achieved at the Brookhaven National Laboratory in New York, in the 2.4-mile-long Relativistic Heavy Ion Collider. The scientists who made this possible were attempting to recreate big-bang like conditions by creating a quark-gluon plasma.

Some facts and figure of the Solar System

The Solar System also has some interesting stories to tell when it comes to temperature. Since there are various planets involved, they all have certain particularities.

Let’s take the sun for example. We all know that it is pretty hot. Its center reaches around 27 million degrees Fahrenheit. If you want to convert this number to Celsius degrees, that would be around 15 million. Its exterior temperature is significantly lower and reaches 10,000 Fahrenheit (which is approximately 5,600 Celsius degrees).

The center of the Earth stands at approximately the same temperature as the surface of the sun, and it is now estimated at 10,800 Fahrenheit (which would mean around 6,000 Celsius degrees).

The sun’s center remains the hottest part of our Solar System, but there’s also a second-best and that is Jupiter which has a remarkably hot core that is roughly five times hotter than the surface of the sun.

However, there are cold temperature extremes as well that we can talk about. The coldest place is actually on the moon, where temperatures registered in some shadowed parts go as low as 30 Kelvin degrees above absolute zero.

 

The zeroth law

The field of thermodynamics had three major laws for a long time, but that changed in 1935 when scientists came up with a fourth one. This later one states that “if two systems are each in thermal equilibrium with a third one, they are also in thermal equilibrium with each other.”

However, once the law defined, scientists realized that it’s actually fundamental to the entire field of thermodynamics and that it can easily stand as a first rule, not as a fourth one. Therefore, they called it the “zeroth law.”

 

Extreme temperatures registered on Earth

Sometimes it seems that people didn’t take the environment into account as much as they should have when they established their homes. Some of these are in the most unlikely places. The coldest city in the world is in Siberia, and it’s called Yakutsk. Its 270,000 inhabitants often face temperatures as low as -40 degrees Fahrenheit.

The highest average temperature was recorded in Dallol, in Ethiopia, which registered an average temperature of 96 degrees in the 1690’s.

However, the record for the hottest workplace goes all the way to South Africa, to the Mponeng gold mine. Rock temperatures can reach 150 degrees Fahrenheit, and ice is pumped into the mine to ensure that people can work there.

Coldest human-made temperature

The coldest temperature ever achieved stands at around one hundred pico Kelvins and it’s necessary to use a magnetic cooling to get to temperatures this low. At these temperatures, matter tends to behave differently, which means there are many more discoveries to be made, especially in quantum mechanics.

 

The Planck temperature

Although throughout this article we’ve been discussing temperatures that could never be measured with the help of a normal underarm thermometer, there’s one more that stands in the farthest extreme and that our scientists only assume it exists. This is the Planck Temperature.

It is the hottest temperature most commonly mentioned in science and it’s believed it only occurred for a fraction of a moment after the Big Bang. Expressed in numbers, it stands at 10^32 Kelvin.

Just to get a grasp of what this means, think about the fact that it’s basically ten billion billion billion times hotter than what we managed to achieve here on earth. That was already 250,000 times hotter than the sun’s core. While it is possible that hotter temperatures exist, they would simply not be able to exist in our today’s reality.

We hope that you’ve enjoyed this article and that you’ll continue to research this fascinating topic further, since it goes from our everyday life that includes taking bath and getting dressed, to numbers so high or low that they remain only as concepts at this point.

If you want to read other interesting things about measuring instruments, you can check out our articles on topics such as effective infrared thermometers or digital thermometers for cooking.

 

 

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An anemometer is the most commonly used instrument which can measure the wind speed. The types of anemometers available are various, suited for specific situations, environments, and measurements.

The categories of anemometers are based on velocity and pressure units.

Velocity anemometers

Velocity anemometers include cup anemometers, vane anemometers, hot-wire anemometers, laser Doppler anemometers, ultrasonic ones and ping-pong-ball models.

 

Cup anemometers

The cup anemometer is a basic type that consists of four hemispherical cups attached to horizontal arms, which are connected to a vertical rod. The wind passing the cups in any horizontal direction spins the rod at a rate roughly proportional to the speed of the wind. Counting the rotations of the rod over a fixed period of time creates a value that is proportional to the average rate of the wind for a broad range of speeds. Another name used for this device is rotational anemometer.

 

Vane anemometers

Vane or propeller anemometer can commonly be described as a windmill. Unlike the cup anemometer, this device has its rod parallel to the direction of the wind, meaning horizontal. As the wind varies in direction, the rod has to be flexible to comply.

 

Hot-wire anemometers

The hot-wire anemometer includes a wire which is electrically heated to a temperature above that of the ambient. The wind flowing past the wire chills it. Since the electrical resistance of most metals is dependent on the temperature of the metal, a measurement can be done between the flow speed and the strength of the wire.

Hot-wire devices can further be classified as constant current anemometers, constant voltage anemometers, and constant-temperature anemometers. The voltage output provided by these units is the result of a specific circuit between the device trying to maintain the particular variable constant, which can be temperature, voltage, or current, following Ohm’s law.

Voltage can be calculated with another measurement instrument called a voltmeter and the electrical resistance with an ohm meter.

 

Laser Doppler anemometers

Laser Doppler anemometers use a beam of light produced by a laser divided into two beams. The particles flow along with air molecules where the beam exits reflect the light back into a detector, where it is measured according to the original laser beam.

When the particles are in fast motion, they produce a Doppler shift that is used to calculate wind speed in the laser’s light.

 

Ultrasonic anemometers

Ultrasonic anemometers were first introduced in the 1950s. They use ultrasonic sound waves to measure wind velocity. They time the speed of the wind according to the time of flight of sonic pulses among pairs of transducers. The determination provided by pairs of sensors can be combined to generate a measurement of velocity in a 1-, 2-, or 3-dimensional flow.

 

Ping-pong ball anemometers

This device is built from a ping-pong ball connected to a string. When the direction of the wind is horizontal, it presses on and moves the ball. As ping-pong balls are very light, they move smoothly even in calm winds. Calculating the angle between the string-ball device and the vertical provides an approximation of the speed of the wind.

 

Pressure anemometers

The first anemometers that measure the pressure of the wind have been categorized into plate and tube classes.

Plate anemometers

These devices consist of flat plates that are suspended from the top for the wind to deflect on the plates. Leon Battista Alberti, an Italian architect invented the first mechanical anemometer in 1450. It was reinvented in 1664 by Robert Hooke. Latest versions consist of flat plates, either circular or square, that are maintained normal to the wind by a wind vane.

 

Tube anemometers

The device consists of a U shaped glass tube containing a liquid manometer, with one of the ends bent horizontally in order to face the wind. The vertical end remains parallel to the wind flow.

When the wind blows into the mouth of the tube, it creates an increase of pressure on one side of the manometer. The wind blowing over the open end causes little change in pressure, on the other side of the manometer. The obtained elevation difference from the two legs of the tube indicates the speed of the wind.

 

 

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What is a Galileo thermometer?

 

You’ve most probably heard that mercury is a dangerous substance if you get exposed to it. If you’ve ever wanted to know more about this topic, then this article comes at the right time.

Before getting into what the dangers of mercury are, let’s take a moment and talk about it in general and what the potential sources of contamination are since there might be some things that could use some clarifications.

Mercury is a naturally occurring element

Mercury is part of what nature gave us by default and it exists in the air, water, and soil. It occurs naturally in our planet’s crust and it’s released into the environment through volcanic activity.

However, human activity is one of the leading causes of mercury releases, through coal-fired power stations, coal burning for residential heating and cooking, waste incinerators, other industrial processes, as well as mining for gold, mercury, and other metals.

There are several types of this substance you can encounter, as these are: elemental (or what is known as metallic), inorganic (through occupational exposure), and organic (to which we are exposed through food). Of course, all of these forms have different degrees of toxicity and effects on health.  

 

How you can get exposed

The story goes like this. The mercury is released into the environment, and from there it can be transformed into methylmercury through bacteria. Methylmercury is the organic form that we can ingest through our diet, and it’s toxic.

Then another process takes place which is called bioaccumulation and which occurs when an organism contains higher concentrations of a certain substance than its surroundings. Methylmercury bioaccumulates in fish and shellfish.

However, this is not the end of the story, as this process goes further and biomagnifies since nature follows its course. Large predatory fish eat the smaller ones, and the result is that they are more likely to ingest, and therefore contain, higher levels of mercury. Smaller fish also acquire some mercury by ingesting plankton.

As stated above, people can be exposed to various types of mercury, depending on the circumstances. However, the main contamination occurs by eating fish and shellfish containing high levels of the substance. Unfortunately, cooking the food does not eliminate mercury; therefore it’s not a solution in this case.

Another main source is occupational, as workers can inhale elemental mercury vapors created by industrial processes.

Sensitive groups

Two types of people are more commonly sensitive to the effects of mercury. The first ones are fetuses, and they are the most susceptible to developmental issues.

If a fetus is exposed to methylmercury in the womb, which can occur due to the mother’s consumption of fish and shellfish, the baby’s brain and nervous system can be affected. The substance’s primary health effect is an impaired neurological development.

Cognitive thinking, attention, language, memory, and fine motor and visual spatial skills can be affected for those children who have been exposed to methylmercury as fetuses.

The second group that is sensitive consists of those people who are regularly exposed to high levels of the substance. Chronic exposure can occur in populations that rely on fishing to survive or for people who are occupationally exposed.

When it comes to fishing populations, studies have shown that between 1.5/1000 and 17/1000 children developed cognitive impairment caused by the consumption of fish that contained mercury. These numbers applied to countries such as Brazil, Canada, Columbia, China, and Greenland.

 

Mercury exposure health effects

Both elemental and methylmercury are toxic and can affect the central and peripheral nervous systems. Inhaling mercury vapors can have harmful effects on the immune, digestive and immune systems, as well as on kidneys and lungs.

The inorganic salts of mercury are corrosive and can affect the eyes, skin, and gastrointestinal tract. They can also lead to kidney toxicity if ingested.

After a significant exposure either through ingestion, inhalation or through the skin, neurological and behavioral disorders can be observed. These symptoms include headaches, memory loss, cognitive and motor dysfunctions, tremors, or insomnia.

 

The type of exposure matters

Right now it seems like the unthinkable, but doctors in the late 19th century were giving patients significant amounts of mercury to drink in order to treat intestinal obstructions.

Although this is by no means advisable, it does lead to the understanding that there’s a significant difference between drinking mercury or being exposed to vapors. Inhalation is more damaging because the invisible particles get straight into the lungs, and from there into the blood system.

Effects on fertility

Recent studies have shown a correlation between high levels of mercury contained in the body through seafood consumption, and otherwise unexplainable infertility phenomena in women or abnormal analysis results in men.

To prevent all of these effects, you can follow the recommendations made by the U.S. Environmental Protection Agency and the Food and Drug Administration on which types of fish and seafood are least contaminated and try eating only those.

 

Prevention measures

Of course, you might be wondering what can you do to avoid getting exposed to this substance. One thing would be to identify all the potential sources that might be right now in your home and make sure they are safely kept.

For example, older underarm thermometers contain mercury in liquid form that, if the instrument gets broken, is potentially dangerous since it vaporizes at room temperature. When that happens, the air is filled with invisible particles that can quickly be absorbed by the body.

The vaporization process takes longer in the case of mercury, so if it gets into cracks and corners and is left there, you can be exposed for days, weeks, or even longer periods.

Another obvious thing to do is to avoid eating seafood during pregnancy, to prevent any contamination that might reach the womb. Once the baby is born, you might want to look into getting one of those safe and useful pediatric thermometers to prevent any type of unfortunate events.

If you suspect any contamination, you should see your doctor, take all the necessary tests, and then, if needed, undergo a dedicated protocol to cleanse your body from it.

 

 

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Science most definitely has a beautiful side, too, and the Galileo thermometer is one of the instruments that translate the exactitude of scientific observations and principles to useful objects that adorn any interior space.

Before taking a look at what a Galileo thermometer is, let’s take a moment and talk about the well-known scientist whose name it is carrying.

Who was Galileo Galilei

Born in Italy in 1564, Galileo Galilei was an astronomer, engineer, physicist, philosopher, and mathematician whose work greatly influenced many of the principles known at the time and altered the course of scientific research and knowledge towards modernity.

Although some of his findings were controversial during his lifetime, they were, of course, correct, thus setting a new path for science. His most notable work that was regarded as highly controversial was on heliocentrism and Copernicanism, which placed the sun at the center of the Solar System.

During his lifetime he was tried by the Inquisition, found suspect of heresy, and forced to recant. Galileo Galilei spent the rest of his days under house arrest. However, during this period he wrote some of his best-known works on kinematics and strength of materials.

He was also the one who discovered that the density of liquid changes as a result of increasing and decreasing temperatures, which, evidently, leads us to our topic, the Galileo thermometer.

 

The true inventors

Although you would expect that this thermometer was invented by the famous scientist, funnily enough, that is not actually the case. Galileo Galilei did invent an air thermometer, better known as a thermoscope, around 1603, but it was not this one.

What we call today the Galileo thermometer was, in fact, invented by a group of academicians and technicians known as the Accademia del Cimento of Florence. It’s true that this group included Galileo’s pupil, Torricelli and Torricelli’s pupil Viviani, but that is pretty much the only connection between the instrument and Galilei himself.

The writings of the time described the device as slow and lazy, and this is accurate, since it uses the changing density of liquids and the principle of buoyancy to measure the outside temperature. Buoyancy determines whether an object floats or sinks in a liquid, this way explaining how ships made of steel float in the water.

It’s actually pretty hard to find another more beautiful way to measure the temperature than this device, although it’s true that the readings are fairly accurate and not as good as those provided by a regular thermometer.

How it’s made

Manufactured since the end of the 17th century, the Galilean thermometer is made up of a sealed glass cylinder, and inside there’s a transparent liquid and a series of bulbs that also carry an attached weight.

Each one of the weights attached to a bulb is also tagged with an engraved number and a degree symbol. When it comes to the weights, they are actually calibrated counterweights and each one is different from the others.

Another particularity that makes this measuring instrument very appealing is the different coloring of each bulb. This is added so that all the liquids involved have the same density, but it’s also the element that adds an overall attraction of what is most definitely a very special thermometer.

 

How it works

You might remember from your science class that an object immersed in a fluid experiences two different forces: gravity which is pulling it downward and buoyancy which is pushing it upward. In the case of this thermometer, the force of gravity is the one that makes it work.

Besides being a beautiful object by itself, the Galileo thermometer uses the bulbs to read temperatures, as they rise and fall depending on these principles. The basic idea is that, as the temperature of the air changes, it transfers to the temperature of the liquid surrounding the bulbs which, as a result, changes its density.

Each bulb has the same volume and the same density, therefore the same magnitude of gravitational and buoyant forces act upon it at any given moment. However, each of these bulbs is also defined by the mass suspended from its base which increases the relative weight of the bulb.

This means that the effect of gravity is also altered compared to the other ones. As the density of the surrounding fluid changes, the force of gravity manages to overcome the buoyant force, thus making the bulbs sink or float. The principle is that as density decreases, the buoyant force does the same.

The temperature of each bulb remains constant so that as the temperature of the surrounding fluid increases, its density decreases. Since the buoyant force follows in the same way, the gravity continues to pull downwards and makes the bulb sink.

How to read a Galileo thermometer

At any given point, some of the bubbles float while others sink, and the one that sinks the most actually indicates the approximate temperature of the surroundings.

A small Galileo thermometer can have 6 degrees Fahrenheit of difference between the bulbs, which means that there’s enough room for errors. Most models cover temperatures between 68 and 84 degrees Fahrenheit which means they are suitable only for indoor spaces that are heated or air conditioned.

In order to read a Galileo thermometer all you have to do is to look at the lowest bulb that is floating and ignore the ones that are touching the bottom of the container. The bulbs that are neutrally buoyant that show the ambient temperature.

If there’s no bulb floating in the gap formed by the sunken and the rising bulbs, simply use the lowest bulb from the floating cluster to read the temperature. This thermometer is certainly not the most precise alternative, but it’s a very clever way to showcase some basic physics principles and have a beautiful object around the house.

If you would like to read about more precise measuring alternatives, you can check out our other articles on topics such as finding an effective infrared thermometer or finding out how an instant thermometer can help you out in your everyday life.

 

 

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Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.

If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.

How it gets released

Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.

First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.

Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.

Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.

 

Types of mercury

This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.

Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.

Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.

All of these forms have different degrees of toxicity and effects on the human body.

How methylmercury is formed

The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.

As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.

 

Exposure to mercury

On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.

Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.

Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.

The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.

In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.

Exposure effect on humans and animals

Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.

Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.

After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.

Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.

 

Preventive measures

Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.

Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.

If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.

Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.

 

 

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We use this term almost every day, but do we really know what’s behind it? The notion of temperature is related to many different things and there’s an entire science behind it. Besides that, there are many cool facts related to temperature that you might not be aware of but that are part of our lives.

In this article, we’ll take a look at only some of them since covering everything like an impossible task. However, here you’ll find seven facts about temperature in general that will make you think about it differently the next time you’ll wonder what to wear if it’s cold or warm outside.

The science behind temperature

Temperature is a measurement of heat energy that expresses how hot or cold something is. Given its usability, this measurement has a significant part in all fields of natural science, including Earth science, physics, chemistry, biology, and medicine.

Different measurement units have been developed to express temperature, the best known ones being the Celsius, Fahrenheit and Kelvin scales. The speed of the molecules is what determines the temperature of a substance. The faster this speed, the hotter the substance.

Another interesting aspect related to temperature regards the boiling point of water (an essential reference point for this topic), which is correlated to and depends on the atmospheric pressure.

Therefore, at sea level water boils at 212 degrees Fahrenheit, in Tiber water boils at 188.6 degrees Fahrenheit, while at the top of Mount Everest the boiling point is at 159.8 degrees Fahrenheit.

 

Hottest human-made temperature

We managed to achieve right here, on Earth, a temperature that is roughly 250,000 times hotter than the core of the sun. In case you are wondering what this would look like in figures, well here’s the answer – the hottest human-made temperature ever recorded is 7.2 trillion degrees Fahrenheit.

This outstanding recording has been achieved at the Brookhaven National Laboratory in New York, in the 2.4-mile-long Relativistic Heavy Ion Collider. The scientists who made this possible were attempting to recreate big-bang like conditions by creating a quark-gluon plasma.

Some facts and figure of the Solar System

The Solar System also has some interesting stories to tell when it comes to temperature. Since there are various planets involved, they all have certain particularities.

Let’s take the sun for example. We all know that it is pretty hot. Its center reaches around 27 million degrees Fahrenheit. If you want to convert this number to Celsius degrees, that would be around 15 million. Its exterior temperature is significantly lower and reaches 10,000 Fahrenheit (which is approximately 5,600 Celsius degrees).

The center of the Earth stands at approximately the same temperature as the surface of the sun, and it is now estimated at 10,800 Fahrenheit (which would mean around 6,000 Celsius degrees).

The sun’s center remains the hottest part of our Solar System, but there’s also a second-best and that is Jupiter which has a remarkably hot core that is roughly five times hotter than the surface of the sun.

However, there are cold temperature extremes as well that we can talk about. The coldest place is actually on the moon, where temperatures registered in some shadowed parts go as low as 30 Kelvin degrees above absolute zero.

 

The zeroth law

The field of thermodynamics had three major laws for a long time, but that changed in 1935 when scientists came up with a fourth one. This later one states that “if two systems are each in thermal equilibrium with a third one, they are also in thermal equilibrium with each other.”

However, once the law defined, scientists realized that it’s actually fundamental to the entire field of thermodynamics and that it can easily stand as a first rule, not as a fourth one. Therefore, they called it the “zeroth law.”

 

Extreme temperatures registered on Earth

Sometimes it seems that people didn’t take the environment into account as much as they should have when they established their homes. Some of these are in the most unlikely places. The coldest city in the world is in Siberia, and it’s called Yakutsk. Its 270,000 inhabitants often face temperatures as low as -40 degrees Fahrenheit.

The highest average temperature was recorded in Dallol, in Ethiopia, which registered an average temperature of 96 degrees in the 1690’s.

However, the record for the hottest workplace goes all the way to South Africa, to the Mponeng gold mine. Rock temperatures can reach 150 degrees Fahrenheit, and ice is pumped into the mine to ensure that people can work there.

Coldest human-made temperature

The coldest temperature ever achieved stands at around one hundred pico Kelvins and it’s necessary to use a magnetic cooling to get to temperatures this low. At these temperatures, matter tends to behave differently, which means there are many more discoveries to be made, especially in quantum mechanics.

 

The Planck temperature

Although throughout this article we’ve been discussing temperatures that could never be measured with the help of a normal underarm thermometer, there’s one more that stands in the farthest extreme and that our scientists only assume it exists. This is the Planck Temperature.

It is the hottest temperature most commonly mentioned in science and it’s believed it only occurred for a fraction of a moment after the Big Bang. Expressed in numbers, it stands at 10^32 Kelvin.

Just to get a grasp of what this means, think about the fact that it’s basically ten billion billion billion times hotter than what we managed to achieve here on earth. That was already 250,000 times hotter than the sun’s core. While it is possible that hotter temperatures exist, they would simply not be able to exist in our today’s reality.

We hope that you’ve enjoyed this article and that you’ll continue to research this fascinating topic further, since it goes from our everyday life that includes taking bath and getting dressed, to numbers so high or low that they remain only as concepts at this point.

If you want to read other interesting things about measuring instruments, you can check out our articles on topics such as effective infrared thermometers or digital thermometers for cooking.

 

 

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An anemometer is the most commonly used instrument which can measure the wind speed. The types of anemometers available are various, suited for specific situations, environments, and measurements.

The categories of anemometers are based on velocity and pressure units.

Velocity anemometers

Velocity anemometers include cup anemometers, vane anemometers, hot-wire anemometers, laser Doppler anemometers, ultrasonic ones and ping-pong-ball models.

 

Cup anemometers

The cup anemometer is a basic type that consists of four hemispherical cups attached to horizontal arms, which are connected to a vertical rod. The wind passing the cups in any horizontal direction spins the rod at a rate roughly proportional to the speed of the wind. Counting the rotations of the rod over a fixed period of time creates a value that is proportional to the average rate of the wind for a broad range of speeds. Another name used for this device is rotational anemometer.

 

Vane anemometers

Vane or propeller anemometer can commonly be described as a windmill. Unlike the cup anemometer, this device has its rod parallel to the direction of the wind, meaning horizontal. As the wind varies in direction, the rod has to be flexible to comply.

 

Hot-wire anemometers

The hot-wire anemometer includes a wire which is electrically heated to a temperature above that of the ambient. The wind flowing past the wire chills it. Since the electrical resistance of most metals is dependent on the temperature of the metal, a measurement can be done between the flow speed and the strength of the wire.

Hot-wire devices can further be classified as constant current anemometers, constant voltage anemometers, and constant-temperature anemometers. The voltage output provided by these units is the result of a specific circuit between the device trying to maintain the particular variable constant, which can be temperature, voltage, or current, following Ohm’s law.

Voltage can be calculated with another measurement instrument called a voltmeter and the electrical resistance with an ohm meter.

 

Laser Doppler anemometers

Laser Doppler anemometers use a beam of light produced by a laser divided into two beams. The particles flow along with air molecules where the beam exits reflect the light back into a detector, where it is measured according to the original laser beam.

When the particles are in fast motion, they produce a Doppler shift that is used to calculate wind speed in the laser’s light.

 

Ultrasonic anemometers

Ultrasonic anemometers were first introduced in the 1950s. They use ultrasonic sound waves to measure wind velocity. They time the speed of the wind according to the time of flight of sonic pulses among pairs of transducers. The determination provided by pairs of sensors can be combined to generate a measurement of velocity in a 1-, 2-, or 3-dimensional flow.

 

Ping-pong ball anemometers

This device is built from a ping-pong ball connected to a string. When the direction of the wind is horizontal, it presses on and moves the ball. As ping-pong balls are very light, they move smoothly even in calm winds. Calculating the angle between the string-ball device and the vertical provides an approximation of the speed of the wind.

 

Pressure anemometers

The first anemometers that measure the pressure of the wind have been categorized into plate and tube classes.

Plate anemometers

These devices consist of flat plates that are suspended from the top for the wind to deflect on the plates. Leon Battista Alberti, an Italian architect invented the first mechanical anemometer in 1450. It was reinvented in 1664 by Robert Hooke. Latest versions consist of flat plates, either circular or square, that are maintained normal to the wind by a wind vane.

 

Tube anemometers

The device consists of a U shaped glass tube containing a liquid manometer, with one of the ends bent horizontally in order to face the wind. The vertical end remains parallel to the wind flow.

When the wind blows into the mouth of the tube, it creates an increase of pressure on one side of the manometer. The wind blowing over the open end causes little change in pressure, on the other side of the manometer. The obtained elevation difference from the two legs of the tube indicates the speed of the wind.

 

 

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Is mercury poisonous?

 

You’ve most probably heard that mercury is a dangerous substance if you get exposed to it. If you’ve ever wanted to know more about this topic, then this article comes at the right time.

Before getting into what the dangers of mercury are, let’s take a moment and talk about it in general and what the potential sources of contamination are since there might be some things that could use some clarifications.

Mercury is a naturally occurring element

Mercury is part of what nature gave us by default and it exists in the air, water, and soil. It occurs naturally in our planet’s crust and it’s released into the environment through volcanic activity.

However, human activity is one of the leading causes of mercury releases, through coal-fired power stations, coal burning for residential heating and cooking, waste incinerators, other industrial processes, as well as mining for gold, mercury, and other metals.

There are several types of this substance you can encounter, as these are: elemental (or what is known as metallic), inorganic (through occupational exposure), and organic (to which we are exposed through food). Of course, all of these forms have different degrees of toxicity and effects on health.  

 

How you can get exposed

The story goes like this. The mercury is released into the environment, and from there it can be transformed into methylmercury through bacteria. Methylmercury is the organic form that we can ingest through our diet, and it’s toxic.

Then another process takes place which is called bioaccumulation and which occurs when an organism contains higher concentrations of a certain substance than its surroundings. Methylmercury bioaccumulates in fish and shellfish.

However, this is not the end of the story, as this process goes further and biomagnifies since nature follows its course. Large predatory fish eat the smaller ones, and the result is that they are more likely to ingest, and therefore contain, higher levels of mercury. Smaller fish also acquire some mercury by ingesting plankton.

As stated above, people can be exposed to various types of mercury, depending on the circumstances. However, the main contamination occurs by eating fish and shellfish containing high levels of the substance. Unfortunately, cooking the food does not eliminate mercury; therefore it’s not a solution in this case.

Another main source is occupational, as workers can inhale elemental mercury vapors created by industrial processes.

Sensitive groups

Two types of people are more commonly sensitive to the effects of mercury. The first ones are fetuses, and they are the most susceptible to developmental issues.

If a fetus is exposed to methylmercury in the womb, which can occur due to the mother’s consumption of fish and shellfish, the baby’s brain and nervous system can be affected. The substance’s primary health effect is an impaired neurological development.

Cognitive thinking, attention, language, memory, and fine motor and visual spatial skills can be affected for those children who have been exposed to methylmercury as fetuses.

The second group that is sensitive consists of those people who are regularly exposed to high levels of the substance. Chronic exposure can occur in populations that rely on fishing to survive or for people who are occupationally exposed.

When it comes to fishing populations, studies have shown that between 1.5/1000 and 17/1000 children developed cognitive impairment caused by the consumption of fish that contained mercury. These numbers applied to countries such as Brazil, Canada, Columbia, China, and Greenland.

 

Mercury exposure health effects

Both elemental and methylmercury are toxic and can affect the central and peripheral nervous systems. Inhaling mercury vapors can have harmful effects on the immune, digestive and immune systems, as well as on kidneys and lungs.

The inorganic salts of mercury are corrosive and can affect the eyes, skin, and gastrointestinal tract. They can also lead to kidney toxicity if ingested.

After a significant exposure either through ingestion, inhalation or through the skin, neurological and behavioral disorders can be observed. These symptoms include headaches, memory loss, cognitive and motor dysfunctions, tremors, or insomnia.

 

The type of exposure matters

Right now it seems like the unthinkable, but doctors in the late 19th century were giving patients significant amounts of mercury to drink in order to treat intestinal obstructions.

Although this is by no means advisable, it does lead to the understanding that there’s a significant difference between drinking mercury or being exposed to vapors. Inhalation is more damaging because the invisible particles get straight into the lungs, and from there into the blood system.

Effects on fertility

Recent studies have shown a correlation between high levels of mercury contained in the body through seafood consumption, and otherwise unexplainable infertility phenomena in women or abnormal analysis results in men.

To prevent all of these effects, you can follow the recommendations made by the U.S. Environmental Protection Agency and the Food and Drug Administration on which types of fish and seafood are least contaminated and try eating only those.

 

Prevention measures

Of course, you might be wondering what can you do to avoid getting exposed to this substance. One thing would be to identify all the potential sources that might be right now in your home and make sure they are safely kept.

For example, older underarm thermometers contain mercury in liquid form that, if the instrument gets broken, is potentially dangerous since it vaporizes at room temperature. When that happens, the air is filled with invisible particles that can quickly be absorbed by the body.

The vaporization process takes longer in the case of mercury, so if it gets into cracks and corners and is left there, you can be exposed for days, weeks, or even longer periods.

Another obvious thing to do is to avoid eating seafood during pregnancy, to prevent any contamination that might reach the womb. Once the baby is born, you might want to look into getting one of those safe and useful pediatric thermometers to prevent any type of unfortunate events.

If you suspect any contamination, you should see your doctor, take all the necessary tests, and then, if needed, undergo a dedicated protocol to cleanse your body from it.

 

 

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Science most definitely has a beautiful side, too, and the Galileo thermometer is one of the instruments that translate the exactitude of scientific observations and principles to useful objects that adorn any interior space.

Before taking a look at what a Galileo thermometer is, let’s take a moment and talk about the well-known scientist whose name it is carrying.

Who was Galileo Galilei

Born in Italy in 1564, Galileo Galilei was an astronomer, engineer, physicist, philosopher, and mathematician whose work greatly influenced many of the principles known at the time and altered the course of scientific research and knowledge towards modernity.

Although some of his findings were controversial during his lifetime, they were, of course, correct, thus setting a new path for science. His most notable work that was regarded as highly controversial was on heliocentrism and Copernicanism, which placed the sun at the center of the Solar System.

During his lifetime he was tried by the Inquisition, found suspect of heresy, and forced to recant. Galileo Galilei spent the rest of his days under house arrest. However, during this period he wrote some of his best-known works on kinematics and strength of materials.

He was also the one who discovered that the density of liquid changes as a result of increasing and decreasing temperatures, which, evidently, leads us to our topic, the Galileo thermometer.

 

The true inventors

Although you would expect that this thermometer was invented by the famous scientist, funnily enough, that is not actually the case. Galileo Galilei did invent an air thermometer, better known as a thermoscope, around 1603, but it was not this one.

What we call today the Galileo thermometer was, in fact, invented by a group of academicians and technicians known as the Accademia del Cimento of Florence. It’s true that this group included Galileo’s pupil, Torricelli and Torricelli’s pupil Viviani, but that is pretty much the only connection between the instrument and Galilei himself.

The writings of the time described the device as slow and lazy, and this is accurate, since it uses the changing density of liquids and the principle of buoyancy to measure the outside temperature. Buoyancy determines whether an object floats or sinks in a liquid, this way explaining how ships made of steel float in the water.

It’s actually pretty hard to find another more beautiful way to measure the temperature than this device, although it’s true that the readings are fairly accurate and not as good as those provided by a regular thermometer.

How it’s made

Manufactured since the end of the 17th century, the Galilean thermometer is made up of a sealed glass cylinder, and inside there’s a transparent liquid and a series of bulbs that also carry an attached weight.

Each one of the weights attached to a bulb is also tagged with an engraved number and a degree symbol. When it comes to the weights, they are actually calibrated counterweights and each one is different from the others.

Another particularity that makes this measuring instrument very appealing is the different coloring of each bulb. This is added so that all the liquids involved have the same density, but it’s also the element that adds an overall attraction of what is most definitely a very special thermometer.

 

How it works

You might remember from your science class that an object immersed in a fluid experiences two different forces: gravity which is pulling it downward and buoyancy which is pushing it upward. In the case of this thermometer, the force of gravity is the one that makes it work.

Besides being a beautiful object by itself, the Galileo thermometer uses the bulbs to read temperatures, as they rise and fall depending on these principles. The basic idea is that, as the temperature of the air changes, it transfers to the temperature of the liquid surrounding the bulbs which, as a result, changes its density.

Each bulb has the same volume and the same density, therefore the same magnitude of gravitational and buoyant forces act upon it at any given moment. However, each of these bulbs is also defined by the mass suspended from its base which increases the relative weight of the bulb.

This means that the effect of gravity is also altered compared to the other ones. As the density of the surrounding fluid changes, the force of gravity manages to overcome the buoyant force, thus making the bulbs sink or float. The principle is that as density decreases, the buoyant force does the same.

The temperature of each bulb remains constant so that as the temperature of the surrounding fluid increases, its density decreases. Since the buoyant force follows in the same way, the gravity continues to pull downwards and makes the bulb sink.

How to read a Galileo thermometer

At any given point, some of the bubbles float while others sink, and the one that sinks the most actually indicates the approximate temperature of the surroundings.

A small Galileo thermometer can have 6 degrees Fahrenheit of difference between the bulbs, which means that there’s enough room for errors. Most models cover temperatures between 68 and 84 degrees Fahrenheit which means they are suitable only for indoor spaces that are heated or air conditioned.

In order to read a Galileo thermometer all you have to do is to look at the lowest bulb that is floating and ignore the ones that are touching the bottom of the container. The bulbs that are neutrally buoyant that show the ambient temperature.

If there’s no bulb floating in the gap formed by the sunken and the rising bulbs, simply use the lowest bulb from the floating cluster to read the temperature. This thermometer is certainly not the most precise alternative, but it’s a very clever way to showcase some basic physics principles and have a beautiful object around the house.

If you would like to read about more precise measuring alternatives, you can check out our other articles on topics such as finding an effective infrared thermometer or finding out how an instant thermometer can help you out in your everyday life.

 

 

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Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.

If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.

How it gets released

Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.

First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.

Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.

Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.

 

Types of mercury

This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.

Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.

Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.

All of these forms have different degrees of toxicity and effects on the human body.

How methylmercury is formed

The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.

As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.

 

Exposure to mercury

On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.

Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.

Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.

The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.

In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.

Exposure effect on humans and animals

Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.

Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.

After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.

Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.

 

Preventive measures

Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.

Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.

If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.

Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.

 

 

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We use this term almost every day, but do we really know what’s behind it? The notion of temperature is related to many different things and there’s an entire science behind it. Besides that, there are many cool facts related to temperature that you might not be aware of but that are part of our lives.

In this article, we’ll take a look at only some of them since covering everything like an impossible task. However, here you’ll find seven facts about temperature in general that will make you think about it differently the next time you’ll wonder what to wear if it’s cold or warm outside.

The science behind temperature

Temperature is a measurement of heat energy that expresses how hot or cold something is. Given its usability, this measurement has a significant part in all fields of natural science, including Earth science, physics, chemistry, biology, and medicine.

Different measurement units have been developed to express temperature, the best known ones being the Celsius, Fahrenheit and Kelvin scales. The speed of the molecules is what determines the temperature of a substance. The faster this speed, the hotter the substance.

Another interesting aspect related to temperature regards the boiling point of water (an essential reference point for this topic), which is correlated to and depends on the atmospheric pressure.

Therefore, at sea level water boils at 212 degrees Fahrenheit, in Tiber water boils at 188.6 degrees Fahrenheit, while at the top of Mount Everest the boiling point is at 159.8 degrees Fahrenheit.

 

Hottest human-made temperature

We managed to achieve right here, on Earth, a temperature that is roughly 250,000 times hotter than the core of the sun. In case you are wondering what this would look like in figures, well here’s the answer – the hottest human-made temperature ever recorded is 7.2 trillion degrees Fahrenheit.

This outstanding recording has been achieved at the Brookhaven National Laboratory in New York, in the 2.4-mile-long Relativistic Heavy Ion Collider. The scientists who made this possible were attempting to recreate big-bang like conditions by creating a quark-gluon plasma.

Some facts and figure of the Solar System

The Solar System also has some interesting stories to tell when it comes to temperature. Since there are various planets involved, they all have certain particularities.

Let’s take the sun for example. We all know that it is pretty hot. Its center reaches around 27 million degrees Fahrenheit. If you want to convert this number to Celsius degrees, that would be around 15 million. Its exterior temperature is significantly lower and reaches 10,000 Fahrenheit (which is approximately 5,600 Celsius degrees).

The center of the Earth stands at approximately the same temperature as the surface of the sun, and it is now estimated at 10,800 Fahrenheit (which would mean around 6,000 Celsius degrees).

The sun’s center remains the hottest part of our Solar System, but there’s also a second-best and that is Jupiter which has a remarkably hot core that is roughly five times hotter than the surface of the sun.

However, there are cold temperature extremes as well that we can talk about. The coldest place is actually on the moon, where temperatures registered in some shadowed parts go as low as 30 Kelvin degrees above absolute zero.

 

The zeroth law

The field of thermodynamics had three major laws for a long time, but that changed in 1935 when scientists came up with a fourth one. This later one states that “if two systems are each in thermal equilibrium with a third one, they are also in thermal equilibrium with each other.”

However, once the law defined, scientists realized that it’s actually fundamental to the entire field of thermodynamics and that it can easily stand as a first rule, not as a fourth one. Therefore, they called it the “zeroth law.”

 

Extreme temperatures registered on Earth

Sometimes it seems that people didn’t take the environment into account as much as they should have when they established their homes. Some of these are in the most unlikely places. The coldest city in the world is in Siberia, and it’s called Yakutsk. Its 270,000 inhabitants often face temperatures as low as -40 degrees Fahrenheit.

The highest average temperature was recorded in Dallol, in Ethiopia, which registered an average temperature of 96 degrees in the 1690’s.

However, the record for the hottest workplace goes all the way to South Africa, to the Mponeng gold mine. Rock temperatures can reach 150 degrees Fahrenheit, and ice is pumped into the mine to ensure that people can work there.

Coldest human-made temperature

The coldest temperature ever achieved stands at around one hundred pico Kelvins and it’s necessary to use a magnetic cooling to get to temperatures this low. At these temperatures, matter tends to behave differently, which means there are many more discoveries to be made, especially in quantum mechanics.

 

The Planck temperature

Although throughout this article we’ve been discussing temperatures that could never be measured with the help of a normal underarm thermometer, there’s one more that stands in the farthest extreme and that our scientists only assume it exists. This is the Planck Temperature.

It is the hottest temperature most commonly mentioned in science and it’s believed it only occurred for a fraction of a moment after the Big Bang. Expressed in numbers, it stands at 10^32 Kelvin.

Just to get a grasp of what this means, think about the fact that it’s basically ten billion billion billion times hotter than what we managed to achieve here on earth. That was already 250,000 times hotter than the sun’s core. While it is possible that hotter temperatures exist, they would simply not be able to exist in our today’s reality.

We hope that you’ve enjoyed this article and that you’ll continue to research this fascinating topic further, since it goes from our everyday life that includes taking bath and getting dressed, to numbers so high or low that they remain only as concepts at this point.

If you want to read other interesting things about measuring instruments, you can check out our articles on topics such as effective infrared thermometers or digital thermometers for cooking.

 

 

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An anemometer is the most commonly used instrument which can measure the wind speed. The types of anemometers available are various, suited for specific situations, environments, and measurements.

The categories of anemometers are based on velocity and pressure units.

Velocity anemometers

Velocity anemometers include cup anemometers, vane anemometers, hot-wire anemometers, laser Doppler anemometers, ultrasonic ones and ping-pong-ball models.

 

Cup anemometers

The cup anemometer is a basic type that consists of four hemispherical cups attached to horizontal arms, which are connected to a vertical rod. The wind passing the cups in any horizontal direction spins the rod at a rate roughly proportional to the speed of the wind. Counting the rotations of the rod over a fixed period of time creates a value that is proportional to the average rate of the wind for a broad range of speeds. Another name used for this device is rotational anemometer.

 

Vane anemometers

Vane or propeller anemometer can commonly be described as a windmill. Unlike the cup anemometer, this device has its rod parallel to the direction of the wind, meaning horizontal. As the wind varies in direction, the rod has to be flexible to comply.

 

Hot-wire anemometers

The hot-wire anemometer includes a wire which is electrically heated to a temperature above that of the ambient. The wind flowing past the wire chills it. Since the electrical resistance of most metals is dependent on the temperature of the metal, a measurement can be done between the flow speed and the strength of the wire.

Hot-wire devices can further be classified as constant current anemometers, constant voltage anemometers, and constant-temperature anemometers. The voltage output provided by these units is the result of a specific circuit between the device trying to maintain the particular variable constant, which can be temperature, voltage, or current, following Ohm’s law.

Voltage can be calculated with another measurement instrument called a voltmeter and the electrical resistance with an ohm meter.

 

Laser Doppler anemometers

Laser Doppler anemometers use a beam of light produced by a laser divided into two beams. The particles flow along with air molecules where the beam exits reflect the light back into a detector, where it is measured according to the original laser beam.

When the particles are in fast motion, they produce a Doppler shift that is used to calculate wind speed in the laser’s light.

 

Ultrasonic anemometers

Ultrasonic anemometers were first introduced in the 1950s. They use ultrasonic sound waves to measure wind velocity. They time the speed of the wind according to the time of flight of sonic pulses among pairs of transducers. The determination provided by pairs of sensors can be combined to generate a measurement of velocity in a 1-, 2-, or 3-dimensional flow.

 

Ping-pong ball anemometers

This device is built from a ping-pong ball connected to a string. When the direction of the wind is horizontal, it presses on and moves the ball. As ping-pong balls are very light, they move smoothly even in calm winds. Calculating the angle between the string-ball device and the vertical provides an approximation of the speed of the wind.

 

Pressure anemometers

The first anemometers that measure the pressure of the wind have been categorized into plate and tube classes.

Plate anemometers

These devices consist of flat plates that are suspended from the top for the wind to deflect on the plates. Leon Battista Alberti, an Italian architect invented the first mechanical anemometer in 1450. It was reinvented in 1664 by Robert Hooke. Latest versions consist of flat plates, either circular or square, that are maintained normal to the wind by a wind vane.

 

Tube anemometers

The device consists of a U shaped glass tube containing a liquid manometer, with one of the ends bent horizontally in order to face the wind. The vertical end remains parallel to the wind flow.

When the wind blows into the mouth of the tube, it creates an increase of pressure on one side of the manometer. The wind blowing over the open end causes little change in pressure, on the other side of the manometer. The obtained elevation difference from the two legs of the tube indicates the speed of the wind.

 

 

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7 facts about temperature

 

You’ve most probably heard that mercury is a dangerous substance if you get exposed to it. If you’ve ever wanted to know more about this topic, then this article comes at the right time.

Before getting into what the dangers of mercury are, let’s take a moment and talk about it in general and what the potential sources of contamination are since there might be some things that could use some clarifications.

Mercury is a naturally occurring element

Mercury is part of what nature gave us by default and it exists in the air, water, and soil. It occurs naturally in our planet’s crust and it’s released into the environment through volcanic activity.

However, human activity is one of the leading causes of mercury releases, through coal-fired power stations, coal burning for residential heating and cooking, waste incinerators, other industrial processes, as well as mining for gold, mercury, and other metals.

There are several types of this substance you can encounter, as these are: elemental (or what is known as metallic), inorganic (through occupational exposure), and organic (to which we are exposed through food). Of course, all of these forms have different degrees of toxicity and effects on health.  

 

How you can get exposed

The story goes like this. The mercury is released into the environment, and from there it can be transformed into methylmercury through bacteria. Methylmercury is the organic form that we can ingest through our diet, and it’s toxic.

Then another process takes place which is called bioaccumulation and which occurs when an organism contains higher concentrations of a certain substance than its surroundings. Methylmercury bioaccumulates in fish and shellfish.

However, this is not the end of the story, as this process goes further and biomagnifies since nature follows its course. Large predatory fish eat the smaller ones, and the result is that they are more likely to ingest, and therefore contain, higher levels of mercury. Smaller fish also acquire some mercury by ingesting plankton.

As stated above, people can be exposed to various types of mercury, depending on the circumstances. However, the main contamination occurs by eating fish and shellfish containing high levels of the substance. Unfortunately, cooking the food does not eliminate mercury; therefore it’s not a solution in this case.

Another main source is occupational, as workers can inhale elemental mercury vapors created by industrial processes.

Sensitive groups

Two types of people are more commonly sensitive to the effects of mercury. The first ones are fetuses, and they are the most susceptible to developmental issues.

If a fetus is exposed to methylmercury in the womb, which can occur due to the mother’s consumption of fish and shellfish, the baby’s brain and nervous system can be affected. The substance’s primary health effect is an impaired neurological development.

Cognitive thinking, attention, language, memory, and fine motor and visual spatial skills can be affected for those children who have been exposed to methylmercury as fetuses.

The second group that is sensitive consists of those people who are regularly exposed to high levels of the substance. Chronic exposure can occur in populations that rely on fishing to survive or for people who are occupationally exposed.

When it comes to fishing populations, studies have shown that between 1.5/1000 and 17/1000 children developed cognitive impairment caused by the consumption of fish that contained mercury. These numbers applied to countries such as Brazil, Canada, Columbia, China, and Greenland.

 

Mercury exposure health effects

Both elemental and methylmercury are toxic and can affect the central and peripheral nervous systems. Inhaling mercury vapors can have harmful effects on the immune, digestive and immune systems, as well as on kidneys and lungs.

The inorganic salts of mercury are corrosive and can affect the eyes, skin, and gastrointestinal tract. They can also lead to kidney toxicity if ingested.

After a significant exposure either through ingestion, inhalation or through the skin, neurological and behavioral disorders can be observed. These symptoms include headaches, memory loss, cognitive and motor dysfunctions, tremors, or insomnia.

 

The type of exposure matters

Right now it seems like the unthinkable, but doctors in the late 19th century were giving patients significant amounts of mercury to drink in order to treat intestinal obstructions.

Although this is by no means advisable, it does lead to the understanding that there’s a significant difference between drinking mercury or being exposed to vapors. Inhalation is more damaging because the invisible particles get straight into the lungs, and from there into the blood system.

Effects on fertility

Recent studies have shown a correlation between high levels of mercury contained in the body through seafood consumption, and otherwise unexplainable infertility phenomena in women or abnormal analysis results in men.

To prevent all of these effects, you can follow the recommendations made by the U.S. Environmental Protection Agency and the Food and Drug Administration on which types of fish and seafood are least contaminated and try eating only those.

 

Prevention measures

Of course, you might be wondering what can you do to avoid getting exposed to this substance. One thing would be to identify all the potential sources that might be right now in your home and make sure they are safely kept.

For example, older underarm thermometers contain mercury in liquid form that, if the instrument gets broken, is potentially dangerous since it vaporizes at room temperature. When that happens, the air is filled with invisible particles that can quickly be absorbed by the body.

The vaporization process takes longer in the case of mercury, so if it gets into cracks and corners and is left there, you can be exposed for days, weeks, or even longer periods.

Another obvious thing to do is to avoid eating seafood during pregnancy, to prevent any contamination that might reach the womb. Once the baby is born, you might want to look into getting one of those safe and useful pediatric thermometers to prevent any type of unfortunate events.

If you suspect any contamination, you should see your doctor, take all the necessary tests, and then, if needed, undergo a dedicated protocol to cleanse your body from it.

 

 

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Science most definitely has a beautiful side, too, and the Galileo thermometer is one of the instruments that translate the exactitude of scientific observations and principles to useful objects that adorn any interior space.

Before taking a look at what a Galileo thermometer is, let’s take a moment and talk about the well-known scientist whose name it is carrying.

Who was Galileo Galilei

Born in Italy in 1564, Galileo Galilei was an astronomer, engineer, physicist, philosopher, and mathematician whose work greatly influenced many of the principles known at the time and altered the course of scientific research and knowledge towards modernity.

Although some of his findings were controversial during his lifetime, they were, of course, correct, thus setting a new path for science. His most notable work that was regarded as highly controversial was on heliocentrism and Copernicanism, which placed the sun at the center of the Solar System.

During his lifetime he was tried by the Inquisition, found suspect of heresy, and forced to recant. Galileo Galilei spent the rest of his days under house arrest. However, during this period he wrote some of his best-known works on kinematics and strength of materials.

He was also the one who discovered that the density of liquid changes as a result of increasing and decreasing temperatures, which, evidently, leads us to our topic, the Galileo thermometer.

 

The true inventors

Although you would expect that this thermometer was invented by the famous scientist, funnily enough, that is not actually the case. Galileo Galilei did invent an air thermometer, better known as a thermoscope, around 1603, but it was not this one.

What we call today the Galileo thermometer was, in fact, invented by a group of academicians and technicians known as the Accademia del Cimento of Florence. It’s true that this group included Galileo’s pupil, Torricelli and Torricelli’s pupil Viviani, but that is pretty much the only connection between the instrument and Galilei himself.

The writings of the time described the device as slow and lazy, and this is accurate, since it uses the changing density of liquids and the principle of buoyancy to measure the outside temperature. Buoyancy determines whether an object floats or sinks in a liquid, this way explaining how ships made of steel float in the water.

It’s actually pretty hard to find another more beautiful way to measure the temperature than this device, although it’s true that the readings are fairly accurate and not as good as those provided by a regular thermometer.

How it’s made

Manufactured since the end of the 17th century, the Galilean thermometer is made up of a sealed glass cylinder, and inside there’s a transparent liquid and a series of bulbs that also carry an attached weight.

Each one of the weights attached to a bulb is also tagged with an engraved number and a degree symbol. When it comes to the weights, they are actually calibrated counterweights and each one is different from the others.

Another particularity that makes this measuring instrument very appealing is the different coloring of each bulb. This is added so that all the liquids involved have the same density, but it’s also the element that adds an overall attraction of what is most definitely a very special thermometer.

 

How it works

You might remember from your science class that an object immersed in a fluid experiences two different forces: gravity which is pulling it downward and buoyancy which is pushing it upward. In the case of this thermometer, the force of gravity is the one that makes it work.

Besides being a beautiful object by itself, the Galileo thermometer uses the bulbs to read temperatures, as they rise and fall depending on these principles. The basic idea is that, as the temperature of the air changes, it transfers to the temperature of the liquid surrounding the bulbs which, as a result, changes its density.

Each bulb has the same volume and the same density, therefore the same magnitude of gravitational and buoyant forces act upon it at any given moment. However, each of these bulbs is also defined by the mass suspended from its base which increases the relative weight of the bulb.

This means that the effect of gravity is also altered compared to the other ones. As the density of the surrounding fluid changes, the force of gravity manages to overcome the buoyant force, thus making the bulbs sink or float. The principle is that as density decreases, the buoyant force does the same.

The temperature of each bulb remains constant so that as the temperature of the surrounding fluid increases, its density decreases. Since the buoyant force follows in the same way, the gravity continues to pull downwards and makes the bulb sink.

How to read a Galileo thermometer

At any given point, some of the bubbles float while others sink, and the one that sinks the most actually indicates the approximate temperature of the surroundings.

A small Galileo thermometer can have 6 degrees Fahrenheit of difference between the bulbs, which means that there’s enough room for errors. Most models cover temperatures between 68 and 84 degrees Fahrenheit which means they are suitable only for indoor spaces that are heated or air conditioned.

In order to read a Galileo thermometer all you have to do is to look at the lowest bulb that is floating and ignore the ones that are touching the bottom of the container. The bulbs that are neutrally buoyant that show the ambient temperature.

If there’s no bulb floating in the gap formed by the sunken and the rising bulbs, simply use the lowest bulb from the floating cluster to read the temperature. This thermometer is certainly not the most precise alternative, but it’s a very clever way to showcase some basic physics principles and have a beautiful object around the house.

If you would like to read about more precise measuring alternatives, you can check out our other articles on topics such as finding an effective infrared thermometer or finding out how an instant thermometer can help you out in your everyday life.

 

 

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Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.

If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.

How it gets released

Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.

First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.

Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.

Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.

 

Types of mercury

This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.

Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.

Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.

All of these forms have different degrees of toxicity and effects on the human body.

How methylmercury is formed

The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.

As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.

 

Exposure to mercury

On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.

Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.

Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.

The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.

In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.

Exposure effect on humans and animals

Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.

Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.

After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.

Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.

 

Preventive measures

Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.

Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.

If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.

Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.

 

 

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We use this term almost every day, but do we really know what’s behind it? The notion of temperature is related to many different things and there’s an entire science behind it. Besides that, there are many cool facts related to temperature that you might not be aware of but that are part of our lives.

In this article, we’ll take a look at only some of them since covering everything like an impossible task. However, here you’ll find seven facts about temperature in general that will make you think about it differently the next time you’ll wonder what to wear if it’s cold or warm outside.

The science behind temperature

Temperature is a measurement of heat energy that expresses how hot or cold something is. Given its usability, this measurement has a significant part in all fields of natural science, including Earth science, physics, chemistry, biology, and medicine.

Different measurement units have been developed to express temperature, the best known ones being the Celsius, Fahrenheit and Kelvin scales. The speed of the molecules is what determines the temperature of a substance. The faster this speed, the hotter the substance.

Another interesting aspect related to temperature regards the boiling point of water (an essential reference point for this topic), which is correlated to and depends on the atmospheric pressure.

Therefore, at sea level water boils at 212 degrees Fahrenheit, in Tiber water boils at 188.6 degrees Fahrenheit, while at the top of Mount Everest the boiling point is at 159.8 degrees Fahrenheit.

 

Hottest human-made temperature

We managed to achieve right here, on Earth, a temperature that is roughly 250,000 times hotter than the core of the sun. In case you are wondering what this would look like in figures, well here’s the answer – the hottest human-made temperature ever recorded is 7.2 trillion degrees Fahrenheit.

This outstanding recording has been achieved at the Brookhaven National Laboratory in New York, in the 2.4-mile-long Relativistic Heavy Ion Collider. The scientists who made this possible were attempting to recreate big-bang like conditions by creating a quark-gluon plasma.

Some facts and figure of the Solar System

The Solar System also has some interesting stories to tell when it comes to temperature. Since there are various planets involved, they all have certain particularities.

Let’s take the sun for example. We all know that it is pretty hot. Its center reaches around 27 million degrees Fahrenheit. If you want to convert this number to Celsius degrees, that would be around 15 million. Its exterior temperature is significantly lower and reaches 10,000 Fahrenheit (which is approximately 5,600 Celsius degrees).

The center of the Earth stands at approximately the same temperature as the surface of the sun, and it is now estimated at 10,800 Fahrenheit (which would mean around 6,000 Celsius degrees).

The sun’s center remains the hottest part of our Solar System, but there’s also a second-best and that is Jupiter which has a remarkably hot core that is roughly five times hotter than the surface of the sun.

However, there are cold temperature extremes as well that we can talk about. The coldest place is actually on the moon, where temperatures registered in some shadowed parts go as low as 30 Kelvin degrees above absolute zero.

 

The zeroth law

The field of thermodynamics had three major laws for a long time, but that changed in 1935 when scientists came up with a fourth one. This later one states that “if two systems are each in thermal equilibrium with a third one, they are also in thermal equilibrium with each other.”

However, once the law defined, scientists realized that it’s actually fundamental to the entire field of thermodynamics and that it can easily stand as a first rule, not as a fourth one. Therefore, they called it the “zeroth law.”

 

Extreme temperatures registered on Earth

Sometimes it seems that people didn’t take the environment into account as much as they should have when they established their homes. Some of these are in the most unlikely places. The coldest city in the world is in Siberia, and it’s called Yakutsk. Its 270,000 inhabitants often face temperatures as low as -40 degrees Fahrenheit.

The highest average temperature was recorded in Dallol, in Ethiopia, which registered an average temperature of 96 degrees in the 1690’s.

However, the record for the hottest workplace goes all the way to South Africa, to the Mponeng gold mine. Rock temperatures can reach 150 degrees Fahrenheit, and ice is pumped into the mine to ensure that people can work there.

Coldest human-made temperature

The coldest temperature ever achieved stands at around one hundred pico Kelvins and it’s necessary to use a magnetic cooling to get to temperatures this low. At these temperatures, matter tends to behave differently, which means there are many more discoveries to be made, especially in quantum mechanics.

 

The Planck temperature

Although throughout this article we’ve been discussing temperatures that could never be measured with the help of a normal underarm thermometer, there’s one more that stands in the farthest extreme and that our scientists only assume it exists. This is the Planck Temperature.

It is the hottest temperature most commonly mentioned in science and it’s believed it only occurred for a fraction of a moment after the Big Bang. Expressed in numbers, it stands at 10^32 Kelvin.

Just to get a grasp of what this means, think about the fact that it’s basically ten billion billion billion times hotter than what we managed to achieve here on earth. That was already 250,000 times hotter than the sun’s core. While it is possible that hotter temperatures exist, they would simply not be able to exist in our today’s reality.

We hope that you’ve enjoyed this article and that you’ll continue to research this fascinating topic further, since it goes from our everyday life that includes taking bath and getting dressed, to numbers so high or low that they remain only as concepts at this point.

If you want to read other interesting things about measuring instruments, you can check out our articles on topics such as effective infrared thermometers or digital thermometers for cooking.

 

 

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An anemometer is the most commonly used instrument which can measure the wind speed. The types of anemometers available are various, suited for specific situations, environments, and measurements.

The categories of anemometers are based on velocity and pressure units.

Velocity anemometers

Velocity anemometers include cup anemometers, vane anemometers, hot-wire anemometers, laser Doppler anemometers, ultrasonic ones and ping-pong-ball models.

 

Cup anemometers

The cup anemometer is a basic type that consists of four hemispherical cups attached to horizontal arms, which are connected to a vertical rod. The wind passing the cups in any horizontal direction spins the rod at a rate roughly proportional to the speed of the wind. Counting the rotations of the rod over a fixed period of time creates a value that is proportional to the average rate of the wind for a broad range of speeds. Another name used for this device is rotational anemometer.

 

Vane anemometers

Vane or propeller anemometer can commonly be described as a windmill. Unlike the cup anemometer, this device has its rod parallel to the direction of the wind, meaning horizontal. As the wind varies in direction, the rod has to be flexible to comply.

 

Hot-wire anemometers

The hot-wire anemometer includes a wire which is electrically heated to a temperature above that of the ambient. The wind flowing past the wire chills it. Since the electrical resistance of most metals is dependent on the temperature of the metal, a measurement can be done between the flow speed and the strength of the wire.

Hot-wire devices can further be classified as constant current anemometers, constant voltage anemometers, and constant-temperature anemometers. The voltage output provided by these units is the result of a specific circuit between the device trying to maintain the particular variable constant, which can be temperature, voltage, or current, following Ohm’s law.

Voltage can be calculated with another measurement instrument called a voltmeter and the electrical resistance with an ohm meter.

 

Laser Doppler anemometers

Laser Doppler anemometers use a beam of light produced by a laser divided into two beams. The particles flow along with air molecules where the beam exits reflect the light back into a detector, where it is measured according to the original laser beam.

When the particles are in fast motion, they produce a Doppler shift that is used to calculate wind speed in the laser’s light.

 

Ultrasonic anemometers

Ultrasonic anemometers were first introduced in the 1950s. They use ultrasonic sound waves to measure wind velocity. They time the speed of the wind according to the time of flight of sonic pulses among pairs of transducers. The determination provided by pairs of sensors can be combined to generate a measurement of velocity in a 1-, 2-, or 3-dimensional flow.

 

Ping-pong ball anemometers

This device is built from a ping-pong ball connected to a string. When the direction of the wind is horizontal, it presses on and moves the ball. As ping-pong balls are very light, they move smoothly even in calm winds. Calculating the angle between the string-ball device and the vertical provides an approximation of the speed of the wind.

 

Pressure anemometers

The first anemometers that measure the pressure of the wind have been categorized into plate and tube classes.

Plate anemometers

These devices consist of flat plates that are suspended from the top for the wind to deflect on the plates. Leon Battista Alberti, an Italian architect invented the first mechanical anemometer in 1450. It was reinvented in 1664 by Robert Hooke. Latest versions consist of flat plates, either circular or square, that are maintained normal to the wind by a wind vane.

 

Tube anemometers

The device consists of a U shaped glass tube containing a liquid manometer, with one of the ends bent horizontally in order to face the wind. The vertical end remains parallel to the wind flow.

When the wind blows into the mouth of the tube, it creates an increase of pressure on one side of the manometer. The wind blowing over the open end causes little change in pressure, on the other side of the manometer. The obtained elevation difference from the two legs of the tube indicates the speed of the wind.

 

 

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What types of anemometers are there?

 

You’ve most probably heard that mercury is a dangerous substance if you get exposed to it. If you’ve ever wanted to know more about this topic, then this article comes at the right time.

Before getting into what the dangers of mercury are, let’s take a moment and talk about it in general and what the potential sources of contamination are since there might be some things that could use some clarifications.

Mercury is a naturally occurring element

Mercury is part of what nature gave us by default and it exists in the air, water, and soil. It occurs naturally in our planet’s crust and it’s released into the environment through volcanic activity.

However, human activity is one of the leading causes of mercury releases, through coal-fired power stations, coal burning for residential heating and cooking, waste incinerators, other industrial processes, as well as mining for gold, mercury, and other metals.

There are several types of this substance you can encounter, as these are: elemental (or what is known as metallic), inorganic (through occupational exposure), and organic (to which we are exposed through food). Of course, all of these forms have different degrees of toxicity and effects on health.  

 

How you can get exposed

The story goes like this. The mercury is released into the environment, and from there it can be transformed into methylmercury through bacteria. Methylmercury is the organic form that we can ingest through our diet, and it’s toxic.

Then another process takes place which is called bioaccumulation and which occurs when an organism contains higher concentrations of a certain substance than its surroundings. Methylmercury bioaccumulates in fish and shellfish.

However, this is not the end of the story, as this process goes further and biomagnifies since nature follows its course. Large predatory fish eat the smaller ones, and the result is that they are more likely to ingest, and therefore contain, higher levels of mercury. Smaller fish also acquire some mercury by ingesting plankton.

As stated above, people can be exposed to various types of mercury, depending on the circumstances. However, the main contamination occurs by eating fish and shellfish containing high levels of the substance. Unfortunately, cooking the food does not eliminate mercury; therefore it’s not a solution in this case.

Another main source is occupational, as workers can inhale elemental mercury vapors created by industrial processes.

Sensitive groups

Two types of people are more commonly sensitive to the effects of mercury. The first ones are fetuses, and they are the most susceptible to developmental issues.

If a fetus is exposed to methylmercury in the womb, which can occur due to the mother’s consumption of fish and shellfish, the baby’s brain and nervous system can be affected. The substance’s primary health effect is an impaired neurological development.

Cognitive thinking, attention, language, memory, and fine motor and visual spatial skills can be affected for those children who have been exposed to methylmercury as fetuses.

The second group that is sensitive consists of those people who are regularly exposed to high levels of the substance. Chronic exposure can occur in populations that rely on fishing to survive or for people who are occupationally exposed.

When it comes to fishing populations, studies have shown that between 1.5/1000 and 17/1000 children developed cognitive impairment caused by the consumption of fish that contained mercury. These numbers applied to countries such as Brazil, Canada, Columbia, China, and Greenland.

 

Mercury exposure health effects

Both elemental and methylmercury are toxic and can affect the central and peripheral nervous systems. Inhaling mercury vapors can have harmful effects on the immune, digestive and immune systems, as well as on kidneys and lungs.

The inorganic salts of mercury are corrosive and can affect the eyes, skin, and gastrointestinal tract. They can also lead to kidney toxicity if ingested.

After a significant exposure either through ingestion, inhalation or through the skin, neurological and behavioral disorders can be observed. These symptoms include headaches, memory loss, cognitive and motor dysfunctions, tremors, or insomnia.

 

The type of exposure matters

Right now it seems like the unthinkable, but doctors in the late 19th century were giving patients significant amounts of mercury to drink in order to treat intestinal obstructions.

Although this is by no means advisable, it does lead to the understanding that there’s a significant difference between drinking mercury or being exposed to vapors. Inhalation is more damaging because the invisible particles get straight into the lungs, and from there into the blood system.

Effects on fertility

Recent studies have shown a correlation between high levels of mercury contained in the body through seafood consumption, and otherwise unexplainable infertility phenomena in women or abnormal analysis results in men.

To prevent all of these effects, you can follow the recommendations made by the U.S. Environmental Protection Agency and the Food and Drug Administration on which types of fish and seafood are least contaminated and try eating only those.

 

Prevention measures

Of course, you might be wondering what can you do to avoid getting exposed to this substance. One thing would be to identify all the potential sources that might be right now in your home and make sure they are safely kept.

For example, older underarm thermometers contain mercury in liquid form that, if the instrument gets broken, is potentially dangerous since it vaporizes at room temperature. When that happens, the air is filled with invisible particles that can quickly be absorbed by the body.

The vaporization process takes longer in the case of mercury, so if it gets into cracks and corners and is left there, you can be exposed for days, weeks, or even longer periods.

Another obvious thing to do is to avoid eating seafood during pregnancy, to prevent any contamination that might reach the womb. Once the baby is born, you might want to look into getting one of those safe and useful pediatric thermometers to prevent any type of unfortunate events.

If you suspect any contamination, you should see your doctor, take all the necessary tests, and then, if needed, undergo a dedicated protocol to cleanse your body from it.

 

 

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Science most definitely has a beautiful side, too, and the Galileo thermometer is one of the instruments that translate the exactitude of scientific observations and principles to useful objects that adorn any interior space.

Before taking a look at what a Galileo thermometer is, let’s take a moment and talk about the well-known scientist whose name it is carrying.

Who was Galileo Galilei

Born in Italy in 1564, Galileo Galilei was an astronomer, engineer, physicist, philosopher, and mathematician whose work greatly influenced many of the principles known at the time and altered the course of scientific research and knowledge towards modernity.

Although some of his findings were controversial during his lifetime, they were, of course, correct, thus setting a new path for science. His most notable work that was regarded as highly controversial was on heliocentrism and Copernicanism, which placed the sun at the center of the Solar System.

During his lifetime he was tried by the Inquisition, found suspect of heresy, and forced to recant. Galileo Galilei spent the rest of his days under house arrest. However, during this period he wrote some of his best-known works on kinematics and strength of materials.

He was also the one who discovered that the density of liquid changes as a result of increasing and decreasing temperatures, which, evidently, leads us to our topic, the Galileo thermometer.

 

The true inventors

Although you would expect that this thermometer was invented by the famous scientist, funnily enough, that is not actually the case. Galileo Galilei did invent an air thermometer, better known as a thermoscope, around 1603, but it was not this one.

What we call today the Galileo thermometer was, in fact, invented by a group of academicians and technicians known as the Accademia del Cimento of Florence. It’s true that this group included Galileo’s pupil, Torricelli and Torricelli’s pupil Viviani, but that is pretty much the only connection between the instrument and Galilei himself.

The writings of the time described the device as slow and lazy, and this is accurate, since it uses the changing density of liquids and the principle of buoyancy to measure the outside temperature. Buoyancy determines whether an object floats or sinks in a liquid, this way explaining how ships made of steel float in the water.

It’s actually pretty hard to find another more beautiful way to measure the temperature than this device, although it’s true that the readings are fairly accurate and not as good as those provided by a regular thermometer.

How it’s made

Manufactured since the end of the 17th century, the Galilean thermometer is made up of a sealed glass cylinder, and inside there’s a transparent liquid and a series of bulbs that also carry an attached weight.

Each one of the weights attached to a bulb is also tagged with an engraved number and a degree symbol. When it comes to the weights, they are actually calibrated counterweights and each one is different from the others.

Another particularity that makes this measuring instrument very appealing is the different coloring of each bulb. This is added so that all the liquids involved have the same density, but it’s also the element that adds an overall attraction of what is most definitely a very special thermometer.

 

How it works

You might remember from your science class that an object immersed in a fluid experiences two different forces: gravity which is pulling it downward and buoyancy which is pushing it upward. In the case of this thermometer, the force of gravity is the one that makes it work.

Besides being a beautiful object by itself, the Galileo thermometer uses the bulbs to read temperatures, as they rise and fall depending on these principles. The basic idea is that, as the temperature of the air changes, it transfers to the temperature of the liquid surrounding the bulbs which, as a result, changes its density.

Each bulb has the same volume and the same density, therefore the same magnitude of gravitational and buoyant forces act upon it at any given moment. However, each of these bulbs is also defined by the mass suspended from its base which increases the relative weight of the bulb.

This means that the effect of gravity is also altered compared to the other ones. As the density of the surrounding fluid changes, the force of gravity manages to overcome the buoyant force, thus making the bulbs sink or float. The principle is that as density decreases, the buoyant force does the same.

The temperature of each bulb remains constant so that as the temperature of the surrounding fluid increases, its density decreases. Since the buoyant force follows in the same way, the gravity continues to pull downwards and makes the bulb sink.

How to read a Galileo thermometer

At any given point, some of the bubbles float while others sink, and the one that sinks the most actually indicates the approximate temperature of the surroundings.

A small Galileo thermometer can have 6 degrees Fahrenheit of difference between the bulbs, which means that there’s enough room for errors. Most models cover temperatures between 68 and 84 degrees Fahrenheit which means they are suitable only for indoor spaces that are heated or air conditioned.

In order to read a Galileo thermometer all you have to do is to look at the lowest bulb that is floating and ignore the ones that are touching the bottom of the container. The bulbs that are neutrally buoyant that show the ambient temperature.

If there’s no bulb floating in the gap formed by the sunken and the rising bulbs, simply use the lowest bulb from the floating cluster to read the temperature. This thermometer is certainly not the most precise alternative, but it’s a very clever way to showcase some basic physics principles and have a beautiful object around the house.

If you would like to read about more precise measuring alternatives, you can check out our other articles on topics such as finding an effective infrared thermometer or finding out how an instant thermometer can help you out in your everyday life.

 

 

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Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.

If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.

How it gets released

Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.

First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.

Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.

Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.

 

Types of mercury

This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.

Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.

Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.

All of these forms have different degrees of toxicity and effects on the human body.

How methylmercury is formed

The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.

As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.

 

Exposure to mercury

On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.

Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.

Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.

The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.

In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.

Exposure effect on humans and animals

Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.

Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.

After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.

Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.

 

Preventive measures

Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.

Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.

If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.

Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.

 

 

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We use this term almost every day, but do we really know what’s behind it? The notion of temperature is related to many different things and there’s an entire science behind it. Besides that, there are many cool facts related to temperature that you might not be aware of but that are part of our lives.

In this article, we’ll take a look at only some of them since covering everything like an impossible task. However, here you’ll find seven facts about temperature in general that will make you think about it differently the next time you’ll wonder what to wear if it’s cold or warm outside.

The science behind temperature

Temperature is a measurement of heat energy that expresses how hot or cold something is. Given its usability, this measurement has a significant part in all fields of natural science, including Earth science, physics, chemistry, biology, and medicine.

Different measurement units have been developed to express temperature, the best known ones being the Celsius, Fahrenheit and Kelvin scales. The speed of the molecules is what determines the temperature of a substance. The faster this speed, the hotter the substance.

Another interesting aspect related to temperature regards the boiling point of water (an essential reference point for this topic), which is correlated to and depends on the atmospheric pressure.

Therefore, at sea level water boils at 212 degrees Fahrenheit, in Tiber water boils at 188.6 degrees Fahrenheit, while at the top of Mount Everest the boiling point is at 159.8 degrees Fahrenheit.

 

Hottest human-made temperature

We managed to achieve right here, on Earth, a temperature that is roughly 250,000 times hotter than the core of the sun. In case you are wondering what this would look like in figures, well here’s the answer – the hottest human-made temperature ever recorded is 7.2 trillion degrees Fahrenheit.

This outstanding recording has been achieved at the Brookhaven National Laboratory in New York, in the 2.4-mile-long Relativistic Heavy Ion Collider. The scientists who made this possible were attempting to recreate big-bang like conditions by creating a quark-gluon plasma.

Some facts and figure of the Solar System

The Solar System also has some interesting stories to tell when it comes to temperature. Since there are various planets involved, they all have certain particularities.

Let’s take the sun for example. We all know that it is pretty hot. Its center reaches around 27 million degrees Fahrenheit. If you want to convert this number to Celsius degrees, that would be around 15 million. Its exterior temperature is significantly lower and reaches 10,000 Fahrenheit (which is approximately 5,600 Celsius degrees).

The center of the Earth stands at approximately the same temperature as the surface of the sun, and it is now estimated at 10,800 Fahrenheit (which would mean around 6,000 Celsius degrees).

The sun’s center remains the hottest part of our Solar System, but there’s also a second-best and that is Jupiter which has a remarkably hot core that is roughly five times hotter than the surface of the sun.

However, there are cold temperature extremes as well that we can talk about. The coldest place is actually on the moon, where temperatures registered in some shadowed parts go as low as 30 Kelvin degrees above absolute zero.

 

The zeroth law

The field of thermodynamics had three major laws for a long time, but that changed in 1935 when scientists came up with a fourth one. This later one states that “if two systems are each in thermal equilibrium with a third one, they are also in thermal equilibrium with each other.”

However, once the law defined, scientists realized that it’s actually fundamental to the entire field of thermodynamics and that it can easily stand as a first rule, not as a fourth one. Therefore, they called it the “zeroth law.”

 

Extreme temperatures registered on Earth

Sometimes it seems that people didn’t take the environment into account as much as they should have when they established their homes. Some of these are in the most unlikely places. The coldest city in the world is in Siberia, and it’s called Yakutsk. Its 270,000 inhabitants often face temperatures as low as -40 degrees Fahrenheit.

The highest average temperature was recorded in Dallol, in Ethiopia, which registered an average temperature of 96 degrees in the 1690’s.

However, the record for the hottest workplace goes all the way to South Africa, to the Mponeng gold mine. Rock temperatures can reach 150 degrees Fahrenheit, and ice is pumped into the mine to ensure that people can work there.

Coldest human-made temperature

The coldest temperature ever achieved stands at around one hundred pico Kelvins and it’s necessary to use a magnetic cooling to get to temperatures this low. At these temperatures, matter tends to behave differently, which means there are many more discoveries to be made, especially in quantum mechanics.

 

The Planck temperature

Although throughout this article we’ve been discussing temperatures that could never be measured with the help of a normal underarm thermometer, there’s one more that stands in the farthest extreme and that our scientists only assume it exists. This is the Planck Temperature.

It is the hottest temperature most commonly mentioned in science and it’s believed it only occurred for a fraction of a moment after the Big Bang. Expressed in numbers, it stands at 10^32 Kelvin.

Just to get a grasp of what this means, think about the fact that it’s basically ten billion billion billion times hotter than what we managed to achieve here on earth. That was already 250,000 times hotter than the sun’s core. While it is possible that hotter temperatures exist, they would simply not be able to exist in our today’s reality.

We hope that you’ve enjoyed this article and that you’ll continue to research this fascinating topic further, since it goes from our everyday life that includes taking bath and getting dressed, to numbers so high or low that they remain only as concepts at this point.

If you want to read other interesting things about measuring instruments, you can check out our articles on topics such as effective infrared thermometers or digital thermometers for cooking.

 

 

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An anemometer is the most commonly used instrument which can measure the wind speed. The types of anemometers available are various, suited for specific situations, environments, and measurements.

The categories of anemometers are based on velocity and pressure units.

Velocity anemometers

Velocity anemometers include cup anemometers, vane anemometers, hot-wire anemometers, laser Doppler anemometers, ultrasonic ones and ping-pong-ball models.

 

Cup anemometers

The cup anemometer is a basic type that consists of four hemispherical cups attached to horizontal arms, which are connected to a vertical rod. The wind passing the cups in any horizontal direction spins the rod at a rate roughly proportional to the speed of the wind. Counting the rotations of the rod over a fixed period of time creates a value that is proportional to the average rate of the wind for a broad range of speeds. Another name used for this device is rotational anemometer.

 

Vane anemometers

Vane or propeller anemometer can commonly be described as a windmill. Unlike the cup anemometer, this device has its rod parallel to the direction of the wind, meaning horizontal. As the wind varies in direction, the rod has to be flexible to comply.

 

Hot-wire anemometers

The hot-wire anemometer includes a wire which is electrically heated to a temperature above that of the ambient. The wind flowing past the wire chills it. Since the electrical resistance of most metals is dependent on the temperature of the metal, a measurement can be done between the flow speed and the strength of the wire.

Hot-wire devices can further be classified as constant current anemometers, constant voltage anemometers, and constant-temperature anemometers. The voltage output provided by these units is the result of a specific circuit between the device trying to maintain the particular variable constant, which can be temperature, voltage, or current, following Ohm’s law.

Voltage can be calculated with another measurement instrument called a voltmeter and the electrical resistance with an ohm meter.

 

Laser Doppler anemometers

Laser Doppler anemometers use a beam of light produced by a laser divided into two beams. The particles flow along with air molecules where the beam exits reflect the light back into a detector, where it is measured according to the original laser beam.

When the particles are in fast motion, they produce a Doppler shift that is used to calculate wind speed in the laser’s light.

 

Ultrasonic anemometers

Ultrasonic anemometers were first introduced in the 1950s. They use ultrasonic sound waves to measure wind velocity. They time the speed of the wind according to the time of flight of sonic pulses among pairs of transducers. The determination provided by pairs of sensors can be combined to generate a measurement of velocity in a 1-, 2-, or 3-dimensional flow.

 

Ping-pong ball anemometers

This device is built from a ping-pong ball connected to a string. When the direction of the wind is horizontal, it presses on and moves the ball. As ping-pong balls are very light, they move smoothly even in calm winds. Calculating the angle between the string-ball device and the vertical provides an approximation of the speed of the wind.

 

Pressure anemometers

The first anemometers that measure the pressure of the wind have been categorized into plate and tube classes.

Plate anemometers

These devices consist of flat plates that are suspended from the top for the wind to deflect on the plates. Leon Battista Alberti, an Italian architect invented the first mechanical anemometer in 1450. It was reinvented in 1664 by Robert Hooke. Latest versions consist of flat plates, either circular or square, that are maintained normal to the wind by a wind vane.

 

Tube anemometers

The device consists of a U shaped glass tube containing a liquid manometer, with one of the ends bent horizontally in order to face the wind. The vertical end remains parallel to the wind flow.

When the wind blows into the mouth of the tube, it creates an increase of pressure on one side of the manometer. The wind blowing over the open end causes little change in pressure, on the other side of the manometer. The obtained elevation difference from the two legs of the tube indicates the speed of the wind.

 

 

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Analyzing wind speed with anemometers

 

You’ve most probably heard that mercury is a dangerous substance if you get exposed to it. If you’ve ever wanted to know more about this topic, then this article comes at the right time.

Before getting into what the dangers of mercury are, let’s take a moment and talk about it in general and what the potential sources of contamination are since there might be some things that could use some clarifications.

Mercury is a naturally occurring element

Mercury is part of what nature gave us by default and it exists in the air, water, and soil. It occurs naturally in our planet’s crust and it’s released into the environment through volcanic activity.

However, human activity is one of the leading causes of mercury releases, through coal-fired power stations, coal burning for residential heating and cooking, waste incinerators, other industrial processes, as well as mining for gold, mercury, and other metals.

There are several types of this substance you can encounter, as these are: elemental (or what is known as metallic), inorganic (through occupational exposure), and organic (to which we are exposed through food). Of course, all of these forms have different degrees of toxicity and effects on health.  

 

How you can get exposed

The story goes like this. The mercury is released into the environment, and from there it can be transformed into methylmercury through bacteria. Methylmercury is the organic form that we can ingest through our diet, and it’s toxic.

Then another process takes place which is called bioaccumulation and which occurs when an organism contains higher concentrations of a certain substance than its surroundings. Methylmercury bioaccumulates in fish and shellfish.

However, this is not the end of the story, as this process goes further and biomagnifies since nature follows its course. Large predatory fish eat the smaller ones, and the result is that they are more likely to ingest, and therefore contain, higher levels of mercury. Smaller fish also acquire some mercury by ingesting plankton.

As stated above, people can be exposed to various types of mercury, depending on the circumstances. However, the main contamination occurs by eating fish and shellfish containing high levels of the substance. Unfortunately, cooking the food does not eliminate mercury; therefore it’s not a solution in this case.

Another main source is occupational, as workers can inhale elemental mercury vapors created by industrial processes.

Sensitive groups

Two types of people are more commonly sensitive to the effects of mercury. The first ones are fetuses, and they are the most susceptible to developmental issues.

If a fetus is exposed to methylmercury in the womb, which can occur due to the mother’s consumption of fish and shellfish, the baby’s brain and nervous system can be affected. The substance’s primary health effect is an impaired neurological development.

Cognitive thinking, attention, language, memory, and fine motor and visual spatial skills can be affected for those children who have been exposed to methylmercury as fetuses.

The second group that is sensitive consists of those people who are regularly exposed to high levels of the substance. Chronic exposure can occur in populations that rely on fishing to survive or for people who are occupationally exposed.

When it comes to fishing populations, studies have shown that between 1.5/1000 and 17/1000 children developed cognitive impairment caused by the consumption of fish that contained mercury. These numbers applied to countries such as Brazil, Canada, Columbia, China, and Greenland.

 

Mercury exposure health effects

Both elemental and methylmercury are toxic and can affect the central and peripheral nervous systems. Inhaling mercury vapors can have harmful effects on the immune, digestive and immune systems, as well as on kidneys and lungs.

The inorganic salts of mercury are corrosive and can affect the eyes, skin, and gastrointestinal tract. They can also lead to kidney toxicity if ingested.

After a significant exposure either through ingestion, inhalation or through the skin, neurological and behavioral disorders can be observed. These symptoms include headaches, memory loss, cognitive and motor dysfunctions, tremors, or insomnia.

 

The type of exposure matters

Right now it seems like the unthinkable, but doctors in the late 19th century were giving patients significant amounts of mercury to drink in order to treat intestinal obstructions.

Although this is by no means advisable, it does lead to the understanding that there’s a significant difference between drinking mercury or being exposed to vapors. Inhalation is more damaging because the invisible particles get straight into the lungs, and from there into the blood system.

Effects on fertility

Recent studies have shown a correlation between high levels of mercury contained in the body through seafood consumption, and otherwise unexplainable infertility phenomena in women or abnormal analysis results in men.

To prevent all of these effects, you can follow the recommendations made by the U.S. Environmental Protection Agency and the Food and Drug Administration on which types of fish and seafood are least contaminated and try eating only those.

 

Prevention measures

Of course, you might be wondering what can you do to avoid getting exposed to this substance. One thing would be to identify all the potential sources that might be right now in your home and make sure they are safely kept.

For example, older underarm thermometers contain mercury in liquid form that, if the instrument gets broken, is potentially dangerous since it vaporizes at room temperature. When that happens, the air is filled with invisible particles that can quickly be absorbed by the body.

The vaporization process takes longer in the case of mercury, so if it gets into cracks and corners and is left there, you can be exposed for days, weeks, or even longer periods.

Another obvious thing to do is to avoid eating seafood during pregnancy, to prevent any contamination that might reach the womb. Once the baby is born, you might want to look into getting one of those safe and useful pediatric thermometers to prevent any type of unfortunate events.

If you suspect any contamination, you should see your doctor, take all the necessary tests, and then, if needed, undergo a dedicated protocol to cleanse your body from it.

 

 

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Science most definitely has a beautiful side, too, and the Galileo thermometer is one of the instruments that translate the exactitude of scientific observations and principles to useful objects that adorn any interior space.

Before taking a look at what a Galileo thermometer is, let’s take a moment and talk about the well-known scientist whose name it is carrying.

Who was Galileo Galilei

Born in Italy in 1564, Galileo Galilei was an astronomer, engineer, physicist, philosopher, and mathematician whose work greatly influenced many of the principles known at the time and altered the course of scientific research and knowledge towards modernity.

Although some of his findings were controversial during his lifetime, they were, of course, correct, thus setting a new path for science. His most notable work that was regarded as highly controversial was on heliocentrism and Copernicanism, which placed the sun at the center of the Solar System.

During his lifetime he was tried by the Inquisition, found suspect of heresy, and forced to recant. Galileo Galilei spent the rest of his days under house arrest. However, during this period he wrote some of his best-known works on kinematics and strength of materials.

He was also the one who discovered that the density of liquid changes as a result of increasing and decreasing temperatures, which, evidently, leads us to our topic, the Galileo thermometer.

 

The true inventors

Although you would expect that this thermometer was invented by the famous scientist, funnily enough, that is not actually the case. Galileo Galilei did invent an air thermometer, better known as a thermoscope, around 1603, but it was not this one.

What we call today the Galileo thermometer was, in fact, invented by a group of academicians and technicians known as the Accademia del Cimento of Florence. It’s true that this group included Galileo’s pupil, Torricelli and Torricelli’s pupil Viviani, but that is pretty much the only connection between the instrument and Galilei himself.

The writings of the time described the device as slow and lazy, and this is accurate, since it uses the changing density of liquids and the principle of buoyancy to measure the outside temperature. Buoyancy determines whether an object floats or sinks in a liquid, this way explaining how ships made of steel float in the water.

It’s actually pretty hard to find another more beautiful way to measure the temperature than this device, although it’s true that the readings are fairly accurate and not as good as those provided by a regular thermometer.

How it’s made

Manufactured since the end of the 17th century, the Galilean thermometer is made up of a sealed glass cylinder, and inside there’s a transparent liquid and a series of bulbs that also carry an attached weight.

Each one of the weights attached to a bulb is also tagged with an engraved number and a degree symbol. When it comes to the weights, they are actually calibrated counterweights and each one is different from the others.

Another particularity that makes this measuring instrument very appealing is the different coloring of each bulb. This is added so that all the liquids involved have the same density, but it’s also the element that adds an overall attraction of what is most definitely a very special thermometer.

 

How it works

You might remember from your science class that an object immersed in a fluid experiences two different forces: gravity which is pulling it downward and buoyancy which is pushing it upward. In the case of this thermometer, the force of gravity is the one that makes it work.

Besides being a beautiful object by itself, the Galileo thermometer uses the bulbs to read temperatures, as they rise and fall depending on these principles. The basic idea is that, as the temperature of the air changes, it transfers to the temperature of the liquid surrounding the bulbs which, as a result, changes its density.

Each bulb has the same volume and the same density, therefore the same magnitude of gravitational and buoyant forces act upon it at any given moment. However, each of these bulbs is also defined by the mass suspended from its base which increases the relative weight of the bulb.

This means that the effect of gravity is also altered compared to the other ones. As the density of the surrounding fluid changes, the force of gravity manages to overcome the buoyant force, thus making the bulbs sink or float. The principle is that as density decreases, the buoyant force does the same.

The temperature of each bulb remains constant so that as the temperature of the surrounding fluid increases, its density decreases. Since the buoyant force follows in the same way, the gravity continues to pull downwards and makes the bulb sink.

How to read a Galileo thermometer

At any given point, some of the bubbles float while others sink, and the one that sinks the most actually indicates the approximate temperature of the surroundings.

A small Galileo thermometer can have 6 degrees Fahrenheit of difference between the bulbs, which means that there’s enough room for errors. Most models cover temperatures between 68 and 84 degrees Fahrenheit which means they are suitable only for indoor spaces that are heated or air conditioned.

In order to read a Galileo thermometer all you have to do is to look at the lowest bulb that is floating and ignore the ones that are touching the bottom of the container. The bulbs that are neutrally buoyant that show the ambient temperature.

If there’s no bulb floating in the gap formed by the sunken and the rising bulbs, simply use the lowest bulb from the floating cluster to read the temperature. This thermometer is certainly not the most precise alternative, but it’s a very clever way to showcase some basic physics principles and have a beautiful object around the house.

If you would like to read about more precise measuring alternatives, you can check out our other articles on topics such as finding an effective infrared thermometer or finding out how an instant thermometer can help you out in your everyday life.

 

 

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Mercury is one of the substances we often hear about, especially when it comes to the dangers it poses, but we might have many questions on what it actually is, how to prevent exposures and what its effects might be otherwise.

If you find yourself wishing you would know more about the subject, in this article you’ll learn many useful things and, therefore, you’ll know how to tackle this issue and prevent any exposure in order to live a healthier life.

How it gets released

Before going into the details of its effects, let’s take a moment and talk about what mercury actually is and where you can find it.

First of all, mercury is an element that occurs naturally and can be found in every kind of medium: air, water, and soil. It normally occurs in the earth’s crust and it gets released into the environment through volcanic activity.

Of course, another significant cause of its release into the environment is the human activity. Unfortunately, here as well we have a significant impact through the coal-fired power stations we operate on a global level.

Other sources include residential coal burning for heating and household activities, industrial processes, waste incinerators, as well as mining for various metals such as gold.

 

Types of mercury

This substance that’s liquid at room temperature exists in various forms, so let’s take a look at each of these in order to better understand what the risks are.

Elemental (or metallic) mercury is the liquid substance that we all picture when we think about it. In the atmosphere, most mercury is found in elemental form, but the trick is that it’s a gas rather than a liquid.

Methylmercury is the one you should stay away from as much as possible since it’s the toxic form of mercury found in fish, but more on that a little further in this article. There’s also inorganic mercury to which people are exposed through their occupation.

All of these forms have different degrees of toxicity and effects on the human body.

How methylmercury is formed

The story is pretty simple. Once mercury is released into the environment, it can be transformed into methylmercury by bacteria. This resulting substance then bioaccumulates in fish and shellfish. Bioaccumulation means that an organism has higher concentrations of a certain substance than its surroundings.

As if this would not be enough, a secondary process takes place at the same time, which is biomagnification. Large predatory fish are more likely to contain high levels of mercury since they eat smaller fish that have also acquired mercury through the ingestion of plankton.

 

Exposure to mercury

On some level, all humans are exposed to mercury, although these levels are rather low. However, in some cases, when the levels are very high, problems start to arise. There are two general groups of people who are sensitive to mercury exposure and in these cases, special measure should be taken.

Fetuses are most susceptible to developmental issues if exposed. The presence of methylmercury in the womb can be a result of the mother’s consumption of seafood. This can have a negative impact on the baby’s nervous system and brain.

Given that the primary health effect of this exposure is an impaired neurological development, things such as memory, attention, language, cognitive thinking, motor skills might be affected in those children who were exposed to the substance as fetuses.

The second group is formed by people who are regularly exposed (which is defined as chronic exposure) to high levels of the element. Populations that rely on subsistence fishing and those who are occupationally exposed are prone to be a part of this group.

In populations such as China, Brazil, Canada, Columbia or Greenland, between 1.5/1000 and 17/1000 children showed developmental issues caused by eating fish that contained mercury.

Exposure effect on humans and animals

Mercury is not useful to the human body, so you can at best think about it as poison. Its effects vary depending on a number of factors such as age, duration and form of exposure, and level of toxicity. When it enters the body, mercury is stored in the kidneys, blood, spleen, liver, brain and even bones.

Elemental mercury and methylmercury are toxic to the central nervous system, as well as to the peripheral one. Inhaling it is the worst type of exposure, as it’s quickly absorbed through the lungs and heads towards the organs, leading to effects on the immune, digestive and nervous systems, as well as on lungs and kidneys.

After exposure, whether it’s through inhalation, ingestion or contact with the skin, neurological and behavioral disorders could be observed, including insomnia, tremors, memory loss, headaches or cognitive and motor dysfunctions.

Of course, besides the effects on the human body, the mercury released in the environment has an impact on animals as well. The most prone ones are those that eat other fish-eating animals. Harmful effects can include reduced reproduction, slower development, abnormal behavior or even death.

 

Preventive measures

Besides the measures that should be taken on a global level, there are some things that you can do right away in order to reduce the potential exposure risks you might be facing.

Take a look around your house and if there’s an older version of an underarm thermometer containing mercury, make sure that it is safely stored without running the risk of being broken. Especially if you have children, you should use a digital thermometer for babies and keep everything safe.

If you are pregnant and want to make sure that your baby is protected, avoid eating too much fish and shellfish, especially those species that have been identified as prone to contain high levels of methylmercury. As a rule of thumb, bigger fish, such as marlin, shark, tuna or swordfish, are to be avoided.

Even as the child is in his or her early years, you should be careful and not include too often in the diet those species of fish marked as potentially risky. Keep in mind that children exposed to mercury are particularly sensitive because the ratio between food, water, and air intake and individual body weight is much higher compared to adults.

 

 

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We use this term almost every day, but do we really know what’s behind it? The notion of temperature is related to many different things and there’s an entire science behind it. Besides that, there are many cool facts related to temperature that you might not be aware of but that are part of our lives.

In this article, we’ll take a look at only some of them since covering everything like an impossible task. However, here you’ll find seven facts about temperature in general that will make you think about it differently the next time you’ll wonder what to wear if it’s cold or warm outside.

The science behind temperature

Temperature is a measurement of heat energy that expresses how hot or cold something is. Given its usability, this measurement has a significant part in all fields of natural science, including Earth science, physics, chemistry, biology, and medicine.

Different measurement units have been developed to express temperature, the best known ones being the Celsius, Fahrenheit and Kelvin scales. The speed of the molecules is what determines the temperature of a substance. The faster this speed, the hotter the substance.

Another interesting aspect related to temperature regards the boiling point of water (an essential reference point for this topic), which is correlated to and depends on the atmospheric pressure.

Therefore, at sea level water boils at 212 degrees Fahrenheit, in Tiber water boils at 188.6 degrees Fahrenheit, while at the top of Mount Everest the boiling point is at 159.8 degrees Fahrenheit.

 

Hottest human-made temperature

We managed to achieve right here, on Earth, a temperature that is roughly 250,000 times hotter than the core of the sun. In case you are wondering what this would look like in figures, well here’s the answer – the hottest human-made temperature ever recorded is 7.2 trillion degrees Fahrenheit.

This outstanding recording has been achieved at the Brookhaven National Laboratory in New York, in the 2.4-mile-long Relativistic Heavy Ion Collider. The scientists who made this possible were attempting to recreate big-bang like conditions by creating a quark-gluon plasma.

Some facts and figure of the Solar System

The Solar System also has some interesting stories to tell when it comes to temperature. Since there are various planets involved, they all have certain particularities.

Let’s take the sun for example. We all know that it is pretty hot. Its center reaches around 27 million degrees Fahrenheit. If you want to convert this number to Celsius degrees, that would be around 15 million. Its exterior temperature is significantly lower and reaches 10,000 Fahrenheit (which is approximately 5,600 Celsius degrees).

The center of the Earth stands at approximately the same temperature as the surface of the sun, and it is now estimated at 10,800 Fahrenheit (which would mean around 6,000 Celsius degrees).

The sun’s center remains the hottest part of our Solar System, but there’s also a second-best and that is Jupiter which has a remarkably hot core that is roughly five times hotter than the surface of the sun.

However, there are cold temperature extremes as well that we can talk about. The coldest place is actually on the moon, where temperatures registered in some shadowed parts go as low as 30 Kelvin degrees above absolute zero.

 

The zeroth law

The field of thermodynamics had three major laws for a long time, but that changed in 1935 when scientists came up with a fourth one. This later one states that “if two systems are each in thermal equilibrium with a third one, they are also in thermal equilibrium with each other.”

However, once the law defined, scientists realized that it’s actually fundamental to the entire field of thermodynamics and that it can easily stand as a first rule, not as a fourth one. Therefore, they called it the “zeroth law.”

 

Extreme temperatures registered on Earth

Sometimes it seems that people didn’t take the environment into account as much as they should have when they established their homes. Some of these are in the most unlikely places. The coldest city in the world is in Siberia, and it’s called Yakutsk. Its 270,000 inhabitants often face temperatures as low as -40 degrees Fahrenheit.

The highest average temperature was recorded in Dallol, in Ethiopia, which registered an average temperature of 96 degrees in the 1690’s.

However, the record for the hottest workplace goes all the way to South Africa, to the Mponeng gold mine. Rock temperatures can reach 150 degrees Fahrenheit, and ice is pumped into the mine to ensure that people can work there.

Coldest human-made temperature

The coldest temperature ever achieved stands at around one hundred pico Kelvins and it’s necessary to use a magnetic cooling to get to temperatures this low. At these temperatures, matter tends to behave differently, which means there are many more discoveries to be made, especially in quantum mechanics.

 

The Planck temperature

Although throughout this article we’ve been discussing temperatures that could never be measured with the help of a normal underarm thermometer, there’s one more that stands in the farthest extreme and that our scientists only assume it exists. This is the Planck Temperature.

It is the hottest temperature most commonly mentioned in science and it’s believed it only occurred for a fraction of a moment after the Big Bang. Expressed in numbers, it stands at 10^32 Kelvin.

Just to get a grasp of what this means, think about the fact that it’s basically ten billion billion billion times hotter than what we managed to achieve here on earth. That was already 250,000 times hotter than the sun’s core. While it is possible that hotter temperatures exist, they would simply not be able to exist in our today’s reality.

We hope that you’ve enjoyed this article and that you’ll continue to research this fascinating topic further, since it goes from our everyday life that includes taking bath and getting dressed, to numbers so high or low that they remain only as concepts at this point.

If you want to read other interesting things about measuring instruments, you can check out our articles on topics such as effective infrared thermometers or digital thermometers for cooking.

 

 

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An anemometer is the most commonly used instrument which can measure the wind speed. The types of anemometers available are various, suited for specific situations, environments, and measurements.

The categories of anemometers are based on velocity and pressure units.

Velocity anemometers

Velocity anemometers include cup anemometers, vane anemometers, hot-wire anemometers, laser Doppler anemometers, ultrasonic ones and ping-pong-ball models.

 

Cup anemometers

The cup anemometer is a basic type that consists of four hemispherical cups attached to horizontal arms, which are connected to a vertical rod. The wind passing the cups in any horizontal direction spins the rod at a rate roughly proportional to the speed of the wind. Counting the rotations of the rod over a fixed period of time creates a value that is proportional to the average rate of the wind for a broad range of speeds. Another name used for this device is rotational anemometer.

 

Vane anemometers

Vane or propeller anemometer can commonly be described as a windmill. Unlike the cup anemometer, this device has its rod parallel to the direction of the wind, meaning horizontal. As the wind varies in direction, the rod has to be flexible to comply.

 

Hot-wire anemometers

The hot-wire anemometer includes a wire which is electrically heated to a temperature above that of the ambient. The wind flowing past the wire chills it. Since the electrical resistance of most metals is dependent on the temperature of the metal, a measurement can be done between the flow speed and the strength of the wire.

Hot-wire devices can further be classified as constant current anemometers, constant voltage anemometers, and constant-temperature anemometers. The voltage output provided by these units is the result of a specific circuit between the device trying to maintain the particular variable constant, which can be temperature, voltage, or current, following Ohm’s law.

Voltage can be calculated with another measurement instrument called a voltmeter and the electrical resistance with an ohm meter.

 

Laser Doppler anemometers

Laser Doppler anemometers use a beam of light produced by a laser divided into two beams. The particles flow along with air molecules where the beam exits reflect the light back into a detector, where it is measured according to the original laser beam.

When the particles are in fast motion, they produce a Doppler shift that is used to calculate wind speed in the laser’s light.

 

Ultrasonic anemometers

Ultrasonic anemometers were first introduced in the 1950s. They use ultrasonic sound waves to measure wind velocity. They time the speed of the wind according to the time of flight of sonic pulses among pairs of transducers. The determination provided by pairs of sensors can be combined to generate a measurement of velocity in a 1-, 2-, or 3-dimensional flow.

 

Ping-pong ball anemometers

This device is built from a ping-pong ball connected to a string. When the direction of the wind is horizontal, it presses on and moves the ball. As ping-pong balls are very light, they move smoothly even in calm winds. Calculating the angle between the string-ball device and the vertical provides an approximation of the speed of the wind.

 

Pressure anemometers

The first anemometers that measure the pressure of the wind have been categorized into plate and tube classes.

Plate anemometers

These devices consist of flat plates that are suspended from the top for the wind to deflect on the plates. Leon Battista Alberti, an Italian architect invented the first mechanical anemometer in 1450. It was reinvented in 1664 by Robert Hooke. Latest versions consist of flat plates, either circular or square, that are maintained normal to the wind by a wind vane.

 

Tube anemometers

The device consists of a U shaped glass tube containing a liquid manometer, with one of the ends bent horizontally in order to face the wind. The vertical end remains parallel to the wind flow.

When the wind blows into the mouth of the tube, it creates an increase of pressure on one side of the manometer. The wind blowing over the open end causes little change in pressure, on the other side of the manometer. The obtained elevation difference from the two legs of the tube indicates the speed of the wind.

 

 

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