Tuesday, June 12, 2007

Temperature

Temperature is a physical property of a system that underlies the common notions of hot and cold; something that is hotter has the greater temperature. Temperature is one of the principal parameters of thermodynamics. The temperature of a system is defined as simply the average energy of microscopic motions of a single particle in the system per degree of freedom. For a solid, these microscopic motions are principally the vibrations of the constituent atoms about their sites in the solid. For an ideal monatomic gas, the microscopic motions are the translational motions of the constituent gas particles. For multiatomic gas vibrational and rotational motion should be included too.

Temperature is measured with thermometers that may be calibrated to a variety of temperature scales. Throughout the world (except for in the U.S.), the Celsius scale is used for most temperature measuring purposes. The entire scientific world (the U.S. included) measures temperature using the Celsius scale, and thermodynamic temperature using the Kelvin scale. Many engineering fields in the U.S., especially high-tech ones, also use the Kelvin and Celsius scales. The bulk of the U.S. however, (its lay people, industry, popular meteorology, and government) relies upon the Fahrenheit scale. Other engineering fields in the U.S. also rely upon the Rankine scale when working in thermodynamic-related disciplines such as combustion.

2 comments:

Robyn said...

we've been studying that in science. But you used lots of big words I dont know what they are :(

Tori_Z said...

Don't feel bad, Robyn. I don't know what all the words mean myself. But, you can get the gist of the meanings by reading the words around them and thinking about their meanings. This doesn't work all the time, but it can be useful in learning the meanings of new words when you don't have a dictionary handy. Or, when you do have a dictionary handy but can't be bothered to go and get it. LOL!