Measure the temperature of the mankind learned about 400 years ago.But the first devices that resemble the current thermometers, appeared only in the X V III century.The inventor of the thermometer was the first scientist Gabriel Fahrenheit.All the world was invented by several different temperature scales, some of them were more popular and are still in use, others gradually went out of use.
temperature scale - a system of temperature values which may be compared with each other.Since the temperature does not relate to the quantity to be directly measured, the value associated with changes in its temperature state of a substance (e.g., water).All temperature scale, usually two fixed points corresponding to the selected transition temperature of the thermometric substances in different phases.This so-called reference points.Examples of reference points can serve as a point of boiling water, the point of hardening gold and so on. N. One of the points is taken as the reference point.The interval between them is divided into a certain number of equal segments that are isolated.The unit of measurement of the temperature of one degree is generally accepted.
most popular and have received the most widespread in the world's temperature scale - the scale of Celsius and Fahrenheit.However, look at the order of the existing scale and try to compare them in terms of ease of use and practical benefits.The most prominent of five scales:
1. Fahrenheit scale was invented by Fahrenheit, a German scientist.One cold winter day in 1709 the mercury in the thermometer scientist dropped to a very low temperature, which it proposed to adopt a zero for the new scale.Another reference point was the temperature of the human body.The freezing point of water on the scale of its steel case + 32 °, and a boiling point of + 212 °.Fahrenheit is not particularly well thought-out and comfortable.Previously, it was widely used in English-speaking countries, now - almost exclusively in the United States.
2. On a scale of Reaumur, invented by the French scientist Rene de Reaumur in 1731, the reference point is the lower the freezing point of water.The scale is based on the use of alcohol, which expands when heated, was adopted for the degree thousandth of the volume of alcohol in a vessel and the tube at the origin.Now this scale is out of use.
3. Celsius (proposed by the Swede Anders Celsius in 1742) for the accepted zero temperature of the mixture of ice and water (the temperature at which ice melts), the other main point - the temperature at which water boils.The interval between them was decided to be divided into 100 parts, and one part is taken as the unit of measurement - degree Celsius.This scale is more rational than the Fahrenheit and Reaumur scale, now used everywhere.
4. Kelvin Scale was invented in 1848 by Lord Kelvin (William Thomson, an English scientist).It zero point corresponds to the lowest possible temperature at which molecular motion is terminated substance.This value was theoretically calculated in the study of the properties of gases.Celsius, this value corresponds to approximately - 273 ° C, t. E.zero Celsius equals 273 K. The unit of the new scale was one kelvin (originally called "Kelvin").
5. Rankin Scale (named after the Scottish physicist W. Rankin) is the same principle that the Kelvin scale and dimension the same as the Fahrenheit scale.This system is practically not widespread.
The temperatures, which gives us the Fahrenheit and Celsius, can be easily transformed into each other.When translating "in the mind" (ie. E. Quickly without using special tables) values Fahrenheit to Celsius is necessary to reduce the initial figure of 32 units and multiply by 5/9.On the other hand (from Celsius to Fahrenheit) - to multiply the original value at 9/5 and add 32. For comparison, the temperature of absolute zero Celsius - 273,15 °, for Farengeytu- 459,67 °.
