What is called absolute zero temperature. Absolute zero temperature

ABSOLUTE ZERO

ABSOLUTE ZERO, the temperature at which all components of the system have the least amount of energy allowed by the laws of QUANTUM MECHANICS; zero on the Kelvin temperature scale, or -273.15°C (-459.67° Fahrenheit). At this temperature, the entropy of the system - the amount of energy available to do useful work - is also zero, although the total amount of energy of the system may be non-zero.

Scientific and technical encyclopedic dictionary.

See what "ABSOLUTE ZERO" is in other dictionaries:

Temperature is the minimum limit of temperature that a physical body can have. Absolute zero serves as the starting point for an absolute temperature scale, such as the Kelvin scale. On the Celsius scale, absolute zero corresponds to a temperature of −273 ... Wikipedia

ABSOLUTE ZERO TEMPERATURE- the beginning of the thermodynamic temperature scale; located at 273.16 K (Kelvin) below (see) water, i.e. equal to 273.16°C (Celsius). Absolute zero is the lowest temperature in nature and practically unattainable... Big Polytechnic Encyclopedia

This is the minimum temperature limit that a physical body can have. Absolute zero serves as the starting point for an absolute temperature scale, such as the Kelvin scale. On the Celsius scale, absolute zero corresponds to a temperature of −273.15 °C.... ... Wikipedia

Absolute zero temperature is the minimum temperature limit that a physical body can have. Absolute zero serves as the starting point for an absolute temperature scale, such as the Kelvin scale. On the Celsius scale, absolute zero corresponds to... ... Wikipedia

Razg. Neglected An insignificant, insignificant person. FSRY, 288; BTS, 24; ZS 1996, 33 ...

zero- absolute zero … Dictionary of Russian Idioms

Zero and zero noun, m., used. compare often Morphology: (no) what? zero and zero, why? zero and zero, (see) what? zero and zero, what? zero and zero, what about? about zero, zero; pl. What? zeros and zeros, (no) what? zeros and zeros, why? zeros and zeros, (I see)… … Dmitriev's Explanatory Dictionary

Absolute zero (zero). Razg. Neglected An insignificant, insignificant person. FSRY, 288; BTS, 24; ZS 1996, 33 V zero. 1. Jarg. they say Joking. iron. About severe intoxication. Yuganovs, 471; Vakhitov 2003, 22. 2. Zharg. music Exactly, in full accordance with... ... Large dictionary of Russian sayings

absolute- absolute absurdity, absolute authority, absolute impeccability, absolute disorder, absolute fiction, absolute immunity, absolute leader, absolute minimum, absolute monarch, absolute morality, absolute zero… … Dictionary of Russian Idioms

Books

Absolute zero, Absolute Pavel. The life of all the creations of the mad scientist of the Nes race is very short. But the next experiment has a chance to exist. What awaits him ahead?...

Absolute temperature zero corresponds to 273.15 degrees Celsius below zero, 459.67 below zero Fahrenheit. For the Kelvin temperature scale, this temperature itself is the zero mark.

The essence of absolute zero temperature

The concept of absolute zero comes from the very essence of temperature. Any body that releases into the external environment during. At the same time, body temperature decreases, i.e. less energy remains. Theoretically, this process can continue until the amount of energy reaches such a minimum that the body can no longer give it away.
A distant harbinger of such an idea can already be found in M.V. Lomonosov. The great Russian scientist explained heat by “rotary” movement. Consequently, the maximum degree of cooling is a complete stop of such movement.

According to modern concepts, absolute zero temperature is at which molecules have the lowest possible energy level. With less energy, i.e. at a lower temperature, no physical body can exist.

Theory and practice

Absolute zero temperature is a theoretical concept; it is impossible to achieve it in practice, in principle, even in scientific laboratories with the most sophisticated equipment. But scientists manage to cool the substance to very low temperatures, which are close to absolute zero.

At such temperatures, substances acquire amazing properties that they cannot have under ordinary circumstances. Mercury, which is called "living silver" because it is in a state close to liquid, becomes solid at this temperature - to the point that it can be used to drive nails. Some metals become brittle, like glass. Rubber becomes just as hard. If you hit a rubber object with a hammer at a temperature close to absolute zero, it will break like glass.

This change in properties is also associated with the nature of heat. The higher the temperature of the physical body, the more intense and chaotic the molecules move. As the temperature decreases, the movement becomes less intense and the structure becomes more orderly. So a gas becomes a liquid, and a liquid becomes a solid. The ultimate level of order is the crystal structure. At ultra-low temperatures, even substances that normally remain amorphous, such as rubber, acquire it.

Interesting phenomena also occur with metals. The atoms of the crystal lattice vibrate with less amplitude, electron scattering decreases, and therefore electrical resistance decreases. The metal acquires superconductivity, the practical application of which seems very tempting, although difficult to achieve.

Sources:

Livanova A. Low temperatures, absolute zero and quantum mechanics

Body– this is one of the basic concepts in physics, which means the form of existence of matter or substance. This is a material object that is characterized by volume and mass, sometimes also by other parameters. The physical body is clearly separated from other bodies by a boundary. There are several special types of physical bodies; their listing should not be understood as a classification.

In mechanics, a physical body is most often understood as a material point. This is a kind of abstraction, the main property of which is the fact that the real dimensions of the body can be neglected for solving a specific problem. In other words, a material point is a very specific body that has dimensions, shape and other similar characteristics, but they are not important in order to solve the existing problem. For example, if you need to count an object on a certain section of the path, you can completely ignore its length when solving the problem. Another type of physical body considered by mechanics is an absolutely rigid body. The mechanics of such a body are exactly the same as the mechanics of a material point, but additionally it has other properties. An absolutely rigid body consists of points, but neither the distance between them nor the distribution of mass changes under the loads to which the body is subjected. This means that it cannot be deformed. To determine the position of an absolutely rigid body, it is enough to specify a coordinate system attached to it, usually Cartesian. In most cases, the center of mass is also the center of the coordinate system. There is no absolutely rigid body, but for solving many problems such an abstraction is very convenient, although it is not considered in relativistic mechanics, since with movements whose speed is comparable to the speed of light, this model demonstrates internal contradictions. The opposite of an absolutely rigid body is a deformable body,

The limiting temperature at which the volume of an ideal gas becomes equal to zero is taken as absolute zero temperature. However, the volume of real gases at absolute zero temperature cannot vanish. Does this temperature limit make sense then?

The limiting temperature, the existence of which follows from the Gay-Lussac law, makes sense, since it is practically possible to bring the properties of a real gas closer to the properties of an ideal one. To do this, you need to take an increasingly rarefied gas, so that its density tends to zero. Indeed, as the temperature decreases, the volume of such a gas will tend to the limit, close to zero.

Let's find the value of absolute zero on the Celsius scale. Equating volume VV formula (3.6.4) zero and taking into account that

Hence the absolute zero temperature is

* More accurate absolute zero value: -273.15 °C.

This is the extreme, lowest temperature in nature, that “greatest or last degree of cold”, the existence of which Lomonosov predicted.

Kelvin scale

Kelvin William (Thomson W.) (1824-1907) - an outstanding English physicist, one of the founders of thermodynamics and the molecular kinetic theory of gases.

Kelvin introduced the absolute temperature scale and gave one of the formulations of the second law of thermodynamics in the form of the impossibility of completely converting heat into work. He calculated the size of molecules based on measuring the surface energy of the liquid. In connection with the laying of the transatlantic telegraph cable, Kelvin developed the theory of electromagnetic oscillations and derived a formula for the period of free oscillations in a circuit. For his scientific achievements, W. Thomson received the title of Lord Kelvin.

The English scientist W. Kelvin introduced the absolute temperature scale. Zero temperature on the Kelvin scale corresponds to absolute zero, and the unit of temperature on this scale is equal to a degree on the Celsius scale, so absolute temperature T is related to temperature on the Celsius scale by the formula

(3.7.6)

Figure 3.11 shows the absolute scale and the Celsius scale for comparison.

The SI unit of absolute temperature is called the kelvin (abbreviated K). Therefore, one degree on the Celsius scale is equal to one degree on the Kelvin scale: 1 °C = 1 K.

Thus, absolute temperature, according to the definition given by formula (3.7.6), is a derived quantity that depends on the Celsius temperature and on the experimentally determined value of a. However, it is of fundamental importance.

From the point of view of molecular kinetic theory, absolute temperature is related to the average kinetic energy of the chaotic movement of atoms or molecules. At T = O K the thermal movement of molecules stops. This will be discussed in more detail in Chapter 4.

Dependence of volume on absolute temperature

Using the Kelvin scale, Gay-Lussac's law (3.6.4) can be written in a simpler form. Because

(3.7.7)

The volume of a gas of a given mass at constant pressure is directly proportional to the absolute temperature.

It follows that the ratio of volumes of gas of the same mass in different states at the same pressure is equal to the ratio of absolute temperatures:

(3.7.8)

There is a minimum possible temperature at which the volume (and pressure) of an ideal gas vanishes. This is absolute zero temperature:-273 °C. It is convenient to count the temperature from absolute zero. This is how the absolute temperature scale is constructed.

Absolute zero corresponds to a temperature of −273.15 °C.

It is believed that absolute zero is unattainable in practice. Its existence and position on the temperature scale follows from extrapolation of observed physical phenomena, and such extrapolation shows that at absolute zero the energy of thermal motion of molecules and atoms of a substance should be equal to zero, that is, the chaotic movement of particles stops, and they form an ordered structure, occupying clear position in the nodes of the crystal lattice. However, in fact, even at absolute zero temperature, the regular movements of the particles that make up matter will remain. The remaining oscillations, such as zero-point oscillations, are due to the quantum properties of the particles and the physical vacuum that surrounds them.

At present, in physical laboratories it has been possible to obtain temperatures exceeding absolute zero by only a few millionths of a degree; to achieve it itself, according to the laws of thermodynamics, is impossible.

Notes

Literature

G. Burmin. Assault on absolute zero. - M.: “Children’s Literature”, 1983.

Learning Objective

Understand why absolute zero is a natural indicator of the zero point.

Main points

Absolute zero is universal, that is, all matter is in the ground state at this indicator.
K has quantum mechanical zero energy. But in interpretation, kinetic energy can be zero, and thermal energy disappears.
The lowest temperature in laboratory conditions reached 10-12 K. The minimum natural temperature was 1 K (expansion of gases in the Boomerang Nebula).

Terms

Entropy is a measure of how uniform energy is distributed in a system.
Thermodynamics is a branch of science that studies heat and its relationship with energy and work.

Absolute zero is the minimum temperature at which entropy reaches its lowest value. That is, this is the smallest indicator that can be observed in the system. This is a universal concept and acts as the zero point in the system of temperature units.

Graph of pressure versus temperature for different gases with constant volume. Note that all graphs extrapolate to zero pressure at one temperature

A system at absolute zero is still endowed with quantum mechanical zero-point energy. According to the uncertainty principle, the position of particles cannot be determined with absolute accuracy. If a particle is displaced at absolute zero, it still has a minimum energy reserve. But in classical thermodynamics, kinetic energy can be zero, and thermal energy disappears.

The zero point of a thermodynamic scale, such as Kelvin, is equal to absolute zero. International agreement has established that the temperature of absolute zero reaches 0K on the Kelvin scale and -273.15°C on the Celsius scale. The substance exhibits quantum effects at minimum temperatures, such as superconductivity and superfluidity. The lowest temperature in laboratory conditions was 10-12 K, and in the natural environment - 1 K (rapid expansion of gases in the Boomerang Nebula).

Rapid expansion of gases leads to minimum observed temperature