Thermometers today is absolutely normal thing. The first thing we do, going outside, look how many degrees on the thermometer. But it was not always. Only in 1714 appeared more or less usable thermometer. It was invented by the German physicist Gabriel Fahrenheit.
Initially Fahrenheit constructed two alcohol thermometer, but with their help it was possible to conduct only a relatively accurate measurement. Then the German physicist decided to use a mercury thermometer, this invention proved to be more successful. In their thermometers he used several scales, the latter of which was based on three fixed points. The first was the temperature of the mixture of ice, water and ammonia, denoted by 0 degrees. The second is the temperature of the mixture of ice and water, marked as 32 degrees. The third temperature Cipriano, which corresponded to 212 degrees. This scale was later named after its Creator. The Fahrenheit scale is still used in England and the United States.
Thirty years later, the Swedish astronomer Anders Celsius experimented with mercury thermometer. He conducted experiments to study the dependence of the melting point of ice and boiling point of water from atmospheric pressure. Celsius came to the conclusion that it is expedient to divide the distance between these two points on the temperature scale at 100 intervals. The number 100 has been identified, the melting point of ice. 0 is the boiling point of water.
However, it is convenient to use the scale in ascending order. Student Celsius Martin Streamer turned the scale of the teacher, making it what it has become today. The Celsius scale used in almost all countries.
English scientist William Kelvin in 1860 proposed a new model of the temperature scale, based on the kinetic energy of the molecules. The temperature in the minus 273 degrees (Celsius) corresponds to zero kinetic energy of the molecules. Since none of the substances is not more cooling, the temperature at minus 273 degrees can be considered as "absolute zero". In the Kelvin scale for the beginning taken the absolute zero, and each division is equal to the ordinary degrees Celsius. This scale proved to be very useful for scientists, because it can adequately describe all the phenomena occurring in the Universe.