Absolute temperature - there is such a thing

We all know that the bodies around us are hot or cold. A glass in which pour boiling water is hot, but the same glass, when it is empty, is cold. We feel cold or warmth when we touch the glass. And what exactly do we feel? To understand this scientists introduced a concept such as temperature.

Initially, when the molecular-kinetic theory was not yet created, scientists believed that a special material-the heat-is responsible for the temperature. It is he, or rather, its number, determines whether the body will be hot or cold. This is similar to an assessment of how "strong" a mixture of matter and heat has been obtained. Proceeding from this analogy, the strength of alcoholic beverages and temperature are measured in the same units - degrees.

Now the temperature is considered a measure of the kinetic energy of the molecules and serves, in particular, as a measure of the degree of heating of the bodies. To evaluate it, scientists use energy units: in the system of SI units this will be a joule. But to measure the temperature began long before the advent of the energy theory. As already mentioned, a special unit of measure is used in daily activities - a degree.

Practice several different approaches to measuring temperature. For each of them there is a temperature scale for setting a unit of degree. They are called by the names of scientists who proposed the method of determination - the scale of Fahrenheit, Reaumur, Celsius. The principle is that they take a range of temperatures and divide it into a certain number. So, according to the Celsius system, 0 degrees is equal to the freezing point of water, and 100 degrees to the temperature of its boiling. This range is divided by 100 and gets a value of 1 degree.

In each system, to establish a value of one degree, use their own reference points, while the same body in each of them will have its own temperature. True, its value can be translated from one scale to another. But scientists have introduced a new concept - absolute temperature. It is again connected with the understanding of temperature as a measure of the energy of the thermal motion of molecules.

From this approach it follows that the absolute temperature is one that is counted from absolute zero, which is the temperature at which the thermal motion is completely absent, and the internal energy of the body is minimal. This way of estimating it is made on the so-called Kelvin scale, for the origin in which the absolute zero temperature is assumed equal to minus 273.15 degrees Celsius.

Thus, the absolute temperature in everyday understanding does not differ from the usual one - it has just another starting point. Of course, no one will say that on the street, plus 296.15 degrees Kelvin, when there is plus 23 degrees Celsius, although both figures will be fair. Temperatures on the Kelvin scale are a completely different application, not related to everyday situations.

It turns out that the absolute temperature or temperature on the Kelvin scale is an instrument used mainly by scientists. They apply it when considering a variety of theoretical and practical issues related to the study of properties, possibilities and phenomena occurring in the surrounding world. Ordinary people who are not related to science should be more interested in the practical use of such a notion as absolute temperature.

The introduction of the definition of absolute zero leads to many curious phenomena. For example, when trying to achieve it, there is such a phenomenon as superconductivity. Theoretically, if the conductor of an electric current is cooled to zero Kelvin degrees (0 ° K), thermal motion in the volume of matter will stop, the electrical resistance of the conductor will tend to zero, and current losses will be minimal. However, it is believed that in practice the absolute zero temperature is unattainable, although in laboratory conditions it was possible to approach the given value as close as possible.

No less interesting is the phenomenon of superfluidity. If the absolute temperature of the gas begins to drop, then at a certain value, for each gas of its own, a gas passes into the liquid. When helium turns into a liquid, it acquires the ability to penetrate through the smallest capillaries. For use in everyday life, such phenomena are not yet applied, but they allow us to understand many questions of quantum mechanics and fundamental science.

Such a concept as absolute temperature is used in theoretical studies and practical experiments on the study of the surrounding world. In addition to it, the very concept of temperature from the point of view of the molecular-kinetic theory is considered in the article.