Jasmine Porter Physics 1010 SLCC Discoveries in Thermodynamics: Thermometer Everyone in the world today knows what a thermometer is and how they work but many people don’t know the history behind them including myself. A thermometer is a scale that measures temperature. Thermometers use two types of materials that change when heated and cooled. One material is mercury and expands when heated and contracts when cool. In the United States we measure temperature in Fahrenheit. Other places use Celsius and even Kelvins. Before the thermometer was invented there was something call the thermoscope that was very similar to the thermometer just without the scale. The thermoscope only could tell you when something was getting hotter, and it could also not tell you exact temperature. It would rise and expand and that is how you would know it was getting hotter and then when it would cool it would slowly contract back together. The thermometer was invented by many scientists. It was perfected so much by each inventor that it finally is today what it is. In 1592 Galileo Galilei was the first one to invent the thermometer. “It was simply a round bottom flask with a glass tube coming out the top, which was placed upside down in a container of water or wine.”(True Physics). Galileo’s made a scale for his thermometer to measure the degrees of it. He didn’t specify a certain degrees to be the boiling point of water for his scale on his thermometer. Which made his thermometer not very accurate. In 1641 a man named Ferdinand II Grand Duke of Tuscany created a new thermometer that was closed. He had a colored alcohol in a glass tube. His thermometer worked by when the alcohol would heat up it would expand and the heat would be measured in degrees. Another man then updated the thermometer in 1741, named Gabriel Fahrenheit. This man invented using mercury in the thermometer and that is what we used still up until it became a safety concern. This thermometer gives you a very accurate reading of temperature. Gabriel Fahrenheit also came up with a measurement of degrees based on our body temperature. This is where we get __ degrees F. He created a freezing point and a boiling point of water. He also established how warm our average body temperature should be. This measurement is mostly just used in America today. Another measurement of temperature used today is Celsius. In 1742, there was a Swedish scientist named Anders Celsius. He invented a different way to measure degrees in something called Celsius. He came up with his measurements by dividing the boiling and freezing point by 100 degrees. Celsius is used widely around the world to measure temperature. The last measurement people may use today are the Kelvin. Kelvin degrees were invented by a man named Sir William Thomson, Lord Kelvin of Scotland. “The Kelvin scale is the current standard unit for measuring temperature” (True Physics). This man decided to make 0 degrees the lowest degrees possible. One kelvin is equal to one degree Celsius. I had no idea that that we measured temperature in Kelvins. That was something that I learned that was new. I also never knew that so many people helped invent the thermometer and perfect it, into what it is today. Many people get credibility for this invention because they all made it better in a drastic way. This was interesting to learn about the history behind the thermometer. I enjoyed reading about all the men who contributed in this invention and learned about why we have the degrees names that we do. I learned a lot and am glad I got this chance. Work Cited Bellis, Mary. The History of the Thermometer. http://inventors.about.com/od/tstartinventions/a/History-Of-The-Thermometer.htm. 2013. May, 4. Caldwell, Anthony. Holmes, Declan. History of Thermometers. http://physics.ie/leaving-certphysics/heat/history-of-thermometers/. 2013. May 4, 2013.