COOL Classroom 2.1

Discover Thermometers - What's the Scale?

Temperature is a measurement of the amount of energy in an object. The more energy, the warmer the object.

In 1724, a Dutch-German-Polish physicist Daniel Gabriel Fahrenheit (1686–1736)developed a scale to use while performing experiments. He based his scale on reference points: one point was the freezing temperature of water, the other point was the temperature of a human body. On his scale water freezes at 32 degrees and boils at 212 degrees. This scale is named after him: Fahrenheit.

The Fahrenheit scale was used for weather and climate information, as well as industrial and medical purposes in English-speaking countries until the 1960s. In the late 1960s and 1970s, the Celsius scale replaced Fahrenheit in many countries.

The Celsius scale is named after the Swedish astronomer Anders Celsius (1701–1744), who developed this scale in 1742. He also used the freezing point of water as a reference point, but called it zero degrees on his scale. Water boils at 100 degrees Celsius.

In the picture below you can see the 2 temperature scales and their measurements for freezing and boiling water.

Fahrenheit is still used in the United States and Belize for everyday applications. For example, U.S. weather forecasts, food cooking, and freezing temperatures are typically given in degrees Fahrenheit. Scientists, such as meteorologists, use Celsius or Kelvin in all countries.

There are websites online that will quickly convert a Fahrenheit temperature to a Celsius temperature for you.
Click here to go to the online converter.

An engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907), didn’t want to have ANY negative temperatures. He thought that zero should be the COLDEST possible temperature. So he designed a scale and it is named Kelvin. Absolute zero known as 0 K is −273.15 °C, which is also −459.67 °F. That is COLD… 459 degrees below freezing.

Click here to go to a NASA site to investigate the 3 temperature scales: Celsius, Fahrenheit, and Kelvin.