Temperature: Keeping It Cool Learn all about temperature. Winter is here. In some places that means thermometers hit zero! In countries besides the United States, it hits zero a lot more often because they use Celsius instead of Fahrenheit to measure temperature. We often think of freezing as anything below the temperature when water freezes—32 degrees Fahrenheit or zero Celsius. But things can get much, much colder than that. Let’s explore a few fun facts about temperature, including the ultimate cold, Absolute Zero. Fahrenheit The system used in the U.S., Fahrenheit, was proposed in 1724 by a guy of the same name. As best anyone can tell, he set the freezing point of pure water at 32 degrees based on zero being the freezing point of a brine solution (water with a high concentration of salt). You use Fahrenheit every day. It’s used for the weather report on TV, on the radio, and on weather apps. Almost any car you’ve been in recently will show the temperature somewhere in Fahrenheit. The sign outside your credit union might also show the current temperature in Fahrenheit. Fahrenheit Fun Facts: Water freezes at 32 degrees. Water boils at 212 degrees. Average body temperature is 98.6 degrees. Celsius Celsius is named after the guy that came up with the scale. It was originally known as the centigrade scale because there are 100 degrees between freezing and boiling water,and “centi” means 100 in Latin. When Celsius first came up with his temperature scale, boiling was zero and freezing was 100 degrees—everything was switched around! You have probably used Celsius in science class or heard it while traveling in another country. Cool Celsius Concepts: Water freezes at zero degrees. Water boils at 100 degrees. Average body temperature is 37 Those aren’t the only scales to measure temperature. Fahrenheit and Celsius are the two most common, but there are about six major scales. Most have long gone out of use. One that does get used often, but not in daily life, is the Kelvin scale. The Kelvin scale is different from Celsius and Fahrenheit because it doesn’t base itself on the boiling point and freezing point of water, but on when the atoms of an object stop moving. Wait, what? Atoms can stop moving? Yes! That is known as Absolute Zero. Theoretically, nothing can be colder than that point. Anything colder than that and you start to get into dark matter or matter that does not behave in any rational way. So how cold is Absolute Zero? Minus 273 Celsius or minus 460 Fahrenheit. To give some perspective, the coldest recorded temperature on Earth was minus 89C, or minus 128F, at Russia’s Vostok Station. That was in July of 1983, but since it was in the south pole, it was winter down there. Other random temperature fun facts: Minus 40 is the same in Celsius and Fahrenheit. All matter is affected by temperature change; water is often used as the base because it is so universal. The Sun is 5,600 Kelvin. The Universe ranges between 3,500,000,000K and 3K. Understanding temperature is important in almost every aspect of life from knowing when to go sledding or go to the pool to learning science.