Absolute zero temperature

Absolute zero temperature(less often - absolute zero temperature) - the minimum temperature limit that a physical body in the Universe can have. Absolute zero serves as the origin of an absolute temperature scale, such as the Kelvin scale. In 1954, the X General Conference on Weights and Measures established a thermodynamic temperature scale with one reference point - the triple point of water, the temperature of which was taken to be 273.16 K (exact), which corresponds to 0.01 °C, so that on the Celsius scale the temperature corresponds to absolute zero −273.15 °C.

Phenomena observed near absolute zero

At temperatures close to absolute zero, purely quantum effects can be observed at the macroscopic level, such as:

Notes

Literature

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

see also

Wikimedia Foundation.

• 2010.
• Goering

Kshapanaka

See what “Absolute zero temperature” is in other dictionaries: ABSOLUTE ZERO TEMPERATURE - thermodynamic reference point. temp; located 273.16 K below the triple point temperature (0.01 ° C) of water (273.15 ° C below zero temperature on the Celsius scale, (see TEMPERATURE SCALES). The existence of a thermodynamic temperature scale and A. n. T.… …

Physical encyclopedia absolute zero temperature - the beginning of the absolute temperature reading on the thermodynamic temperature scale. Absolute zero is located 273.16ºC below the triple point temperature of water, which is assumed to be 0.01ºC. Absolute zero temperature is fundamentally unattainable... ...

Physical encyclopedia encyclopedic Dictionary - absoliutusis nulis statusas T sritis Energetika apibrėžtis Termodinaminės temperatūros atskaitos pradžia, esanti 273.16 K žemiau trigubojo vandens taško. Pagal trečiąjį termodinamikos dėsnį, absoliutusis nulis nepasiekiamas. atitikmenys: engl.… …

Aiškinamasis šiluminės ir branduolinės technikos terminų žodynas Absolute zero temperature - the initial reading on the Kelvin scale is a negative temperature of 273.16 degrees on the Celsius scale...

The beginnings of modern natural science- temperature, the beginning of the temperature reading on the thermodynamic temperature scale. Absolute zero is located 273.16°C below the triple point temperature of water (0.01°C). Absolute zero is fundamentally unattainable, temperatures have almost been reached... ... Modern encyclopedia

The beginnings of modern natural science- temperature is the beginning of the temperature reading on the thermodynamic temperature scale. Absolute zero is located at 273.16.C below the temperature of the triple point of water, for which the value is 0.01.C. Absolute zero is fundamentally unattainable (see... ... Big Encyclopedic Dictionary

The beginnings of modern natural science- temperature, expressing the absence of heat, is equal to 218 ° C. Dictionary of foreign words included in the Russian language. Pavlenkov F., 1907. absolute zero temperature (physical) - the lowest possible temperature (273.15°C). Big dictionary... ... Dictionary of foreign words of the Russian language

The beginnings of modern natural science- temperature, the beginning of temperature on the thermodynamic temperature scale (see THERMODYNAMIC TEMPERATURE SCALE). Absolute zero is located 273.16 °C below the temperature of the triple point (see TRIPLE POINT) of water, for which it is accepted ... ... - the beginning of the absolute temperature reading on the thermodynamic temperature scale. Absolute zero is located 273.16ºC below the triple point temperature of water, which is assumed to be 0.01ºC. Absolute zero temperature is fundamentally unattainable... ...

The beginnings of modern natural science- extremely low temperature, at which the thermal movement of molecules stops. The pressure and volume of an ideal gas, according to Boyle-Mariotte’s law, becomes equal to zero, and the beginning of the absolute temperature on the Kelvin scale is taken to be... ... Ecological dictionary

The beginnings of modern natural science- the beginning of the absolute temperature count. Corresponds to 273.16° C. Currently, in physical laboratories it has been possible to obtain a temperature exceeding absolute zero by only a few millionths of a degree, and to achieve it, according to the laws... ... Collier's Encyclopedia

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 is the amount of energy suitable for completing useful work, - also equals zero, although the total amount of energy of the system may be different from 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. Neglect An insignificant, insignificant person. FSRY, 288; BTS, 24; ZS 1996, 33 ...

zero- absolute zero … Dictionary of Russian Idioms

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Absolute zero (zero). Razg. Neglect 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

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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, which they cannot have under normal 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.

Absolute zero(absolute zero) – the beginning of the absolute temperature, starting from 273.16 K below the triple point of water (the equilibrium point of three phases - ice, water and water vapor); At absolute zero, the movement of molecules stops, and they are in a state of “zero” motion. Or: the lowest temperature at which a substance contains no thermal energy.

Absolute zero Start absolute temperature reading. Corresponds to -273.16 ° C. At present, in physical laboratories it has been possible to obtain a temperature exceeding absolute zero by only a few millionths of a degree, but according to the laws of thermodynamics, it is impossible to achieve it. At absolute zero, the system would be in a state with the lowest possible energy (in this state, atoms and molecules would perform “zero” vibrations) and would have zero entropy (zero disorder). The volume of an ideal gas at the point of absolute zero must be equal to zero, and to determine this point, the volume of real helium gas is measured at sequential lowering the temperature until it liquefies at low pressure (-268.9 ° C) and extrapolates to the temperature at which the volume of gas in the absence of liquefaction would become zero. Absolute temperature thermodynamic scale is measured in kelvins, denoted by the symbol K. Absolute thermodynamic the scale and the Celsius scale are simply offset from one another and are related by the ratio K = °C + 273.16 °.

Story

The word “temperature” arose in those days when people believed that more heated bodies contained a larger amount of a special substance - caloric - than less heated ones. Therefore, temperature was perceived as the strength of a mixture of body matter and caloric. For this reason, the units of measurement for the strength of alcoholic beverages and temperature are called the same - degrees.

Since temperature is the kinetic energy of molecules, it is clear that it is most natural to measure it in energy units (i.e. in the SI system in joules). However, temperature measurement began long before the creation of the molecular kinetic theory, so practical scales measure temperature in conventional units - degrees.

Kelvin scale

Thermodynamics uses the Kelvin scale, in which temperature is measured from absolute zero (the state corresponding to the minimum theoretically possible internal energy of a body), and one kelvin is equal to 1/273.16 of the distance from absolute zero to the triple point of water (the state in which ice, water and water pairs are in equilibrium). Boltzmann's constant is used to convert kelvins into energy units. Derived units are also used: kilokelvin, megakelvin, millikelvin, etc.

Celsius

In everyday life, the Celsius scale is used, in which 0 is the freezing point of water, and 100° is the boiling point of water at atmospheric pressure. Since the freezing and boiling points of water are not well defined, the Celsius scale is currently defined using the Kelvin scale: a degree Celsius is equal to a kelvin, absolute zero is taken to be −273.15 °C. The Celsius scale is practically very convenient because water is very common on our planet and our life is based on it. Zero Celsius is a special point for meteorology, since the freezing of atmospheric water changes everything significantly.

Fahrenheit

In England and especially in the USA, the Fahrenheit scale is used. In this scale, the interval from the temperature itself is divided into 100 degrees. cold winter in the city where Fahrenheit lived, to the temperature of the human body. Zero degrees Celsius is 32 degrees Fahrenheit, and a degree Fahrenheit is equal to 5/9 degrees Celsius.

The current definition of the Fahrenheit scale is as follows: it is a temperature scale in which 1 degree (1 °F) is equal to 1/180th the difference between the boiling point of water and the melting temperature of ice at atmospheric pressure, and the melting point of ice is +32 °F. Temperature on the Fahrenheit scale is related to temperature on the Celsius scale (t °C) by the ratio t °C = 5/9 (t °F - 32), 1 °F = 5/9 °C. Proposed by G. Fahrenheit in 1724.

Reaumur scale

Proposed in 1730 by R. A. Reaumur, who described the alcohol thermometer he invented.

The unit is the degree Reaumur (°R), 1 °R is equal to 1/80 of the temperature interval between the reference points - the melting temperature of ice (0 °R) and the boiling point of water (80 °R)

1 °R = 1.25 °C.

Currently, the scale has fallen out of use; it survived longest in France, the author’s homeland.

Comparison of temperature scales

Normal human body temperature is 36.6 °C ±0.7 °C, or 98.2 °F ±1.3 °F. The commonly quoted value of 98.6°F is an exact conversion to Fahrenheit of the 19th century German value of 37°C. Because this value is not in the range normal temperature according to modern ideas, we can say that it contains excessive (incorrect) precision. Some values ​​in this table have been rounded.

Comparison of Fahrenheit and Celsius scales

(o F- Fahrenheit scale, oC- Celsius scale)

To convert degrees Celsius to Kelvin, you must use the formula T=t+T 0 where T is the temperature in kelvins, t is the temperature in degrees Celsius, T 0 =273.15 kelvins. The size of a degree Celsius is equal to a kelvin.

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 the 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.