Is absolute zero. Why can't we reach absolute zero temperatures? Comparison of temperature scales

The limiting temperature at which the volume of an ideal gas becomes equal to zero is taken as absolute zero temperature.

Let's find the value absolute zero on the Celsius scale.
Equating volume V in formula (3.1) zero and taking into account that

.

Hence the absolute zero temperature is

t= –273 °C. 2

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

The highest temperatures on Earth—hundreds of millions of degrees—are obtained during explosions of thermonuclear bombs. Even higher temperatures are typical for the inner regions of some stars.

2More accurate value of absolute zero: –273.15 °C.

Kelvin scale

The English scientist W. Kelvin introduced absolute scale temperatures 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

T = t + 273. (3.2)

In Fig. 3.2 shows the absolute scale and the Celsius scale for comparison.

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

Thus, absolute temperature, according to the definition given by formula (3.2), is a derived quantity that depends on the Celsius temperature and on the experimentally determined value of a.

Reader: Which one then physical meaning has an absolute temperature?

Let us write expression (3.1) in the form

.

Considering that temperature on the Kelvin scale is related to temperature on the Celsius scale by the relation T = t + 273, we get

Where T 0 = 273 K, or

Since this relation is valid for arbitrary temperature T, then Gay-Lussac’s law can be formulated as follows:

For a given mass of gas at p = const the following relation holds:

Task 3.1. At a temperature T 1 = 300 K gas volume V 1 = 5.0 l. Determine the volume of gas at the same pressure and temperature T= 400 K.

STOP! Decide for yourself: A1, B6, C2.

Problem 3.2. During isobaric heating, the volume of air increased by 1%. By what percentage did the absolute temperature increase?

= 0,01.

Answer: 1 %.

Let's remember the resulting formula

STOP! Decide for yourself: A2, A3, B1, B5.

Charles's Law

The French scientist Charles experimentally established that if a gas is heated so that its volume remains constant, the pressure of the gas will increase. The dependence of pressure on temperature has the form:

R(t) = p 0 (1 + b t), (3.6)

Where R(t) – pressure at temperature t°C; R 0 – pressure at 0 °C; b is the temperature coefficient of pressure, which is the same for all gases: 1/K.

Reader: Surprisingly, the temperature coefficient of pressure b is exactly equal to the temperature coefficient of volumetric expansion a!

Let us take a certain mass of gas with a volume V 0 at temperature T 0 and pressure R 0 . For the first time, maintaining the gas pressure constant, we heat it to a temperature T 1 . Then the gas will have a volume V 1 = V 0 (1 + a t) and pressure R 0 .

The second time, maintaining the volume of gas constant, we heat it to the same temperature T 1 . Then the gas will have pressure R 1 = R 0 (1 + b t) and volume V 0 .

Since in both cases the gas temperature is the same, the Boyle–Mariotte law is valid:

p 0 V 1 = p 1 V 0 Þ R 0 V 0 (1 + a t) = R 0 (1 + b t)V 0 Þ

Þ 1 + a t = 1 + b tÞ a = b.

So it's not surprising that a = b, no!

Let us rewrite Charles' law in the form

.

Considering that T = t°С + 273 °С, T 0 = 273 °C, we get

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.

see also

Wikimedia Foundation. 2010.

See what “Absolute zero” is in other dictionaries:

Temperatures, the origin 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 ... ... encyclopedic Dictionary

Temperatures, the origin of temperature 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

Temperatures is the starting point for temperature 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

Temperature, which expresses 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

absolute zero- The extremely low temperature at which the thermal movement of molecules stops; on the Kelvin scale, absolute zero (0°K) corresponds to –273.16±0.01°C... Dictionary of Geography

Noun, number of synonyms: 15 round zero (8) small man (32) small fry ... Synonym dictionary

The 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

absolute zero- - [A.S. Goldberg. English-Russian energy dictionary. 2006] Energy topics in general EN zeropoint ... Technical Translator's Guide

The beginning of the absolute temperature reference. 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- absoliutusis nulis statusas T sritis Standartizacija ir metrologija apibrėžtis Termodinaminės temperatūros atskaitos pradžia, esanti 273.16 K žemiau vandens trigubojo taško. Tai 273.16 °C, 459.69 °F arba 0 K temperatūra. atitikmenys: engl.… … Penkiakalbis aiškinamasis metrologijos terminų žodynas

absolute zero- absoliutusis nulis statusas T sritis chemija apibrėžtis Kelvino skalės nulis (−273.16 °C). atitikmenys: engl. absolute zero rus. absolute zero... Chemijos terminų aiškinamasis žodynas

Any measurement requires the presence of a reference point. Temperature is no exception. For the Fahrenheit scale, this zero mark is the temperature of snow mixed with table salt; for the Celsius scale, it is the freezing temperature of water. But there is a special temperature reference point - absolute zero.

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 has energy that it gives off to external environment during heat transfer. 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 a state of matter in which molecules have the lowest possible energy level. With less energy, i.e. at lower temperatures none physical body cannot 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 and brittle. 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. Atoms crystal lattice oscillate with less amplitude, electron scattering decreases, and therefore electrical resistance decreases. The metal acquires superconductivity, practical use which seems very tempting, although difficult to achieve.

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... ... encyclopedic Dictionary

absolute zero temperature- 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

ABSOLUTE ZERO- 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

ABSOLUTE ZERO- temperature is the starting point of temperature 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

ABSOLUTE ZERO- 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

ABSOLUTE ZERO- 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 ... ... encyclopedic Dictionary

ABSOLUTE ZERO- 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

ABSOLUTE ZERO- 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

The physical concept of “absolute zero temperature” has for modern science very important: closely related to it is the concept of superconductivity, the discovery of which created a real sensation in the second half of the twentieth century.

To understand what absolute zero is, you should turn to the works of such famous physicists as G. Fahrenheit, A. Celsius, J. Gay-Lussac and W. Thomson. They played a key role in the creation of the main temperature scales still in use today.

The first to propose his temperature scale was the German physicist G. Fahrenheit in 1714. At the same time, the temperature of the mixture, which included snow and ammonia, was taken as absolute zero, that is, as the lowest point of this scale. The next important indicator was which became equal to 1000. Accordingly, each division of this scale was called “degree Fahrenheit”, and the scale itself was called “Fahrenheit scale”.

30 years later, the Swedish astronomer A. Celsius proposed his own temperature scale, where the main points were the melting temperature of ice and water. This scale was called the “Celsius scale”; it is still popular in most countries of the world, including Russia.

In 1802, while conducting his famous experiments, the French scientist J. Gay-Lussac discovered that the volume of a gas at constant pressure is directly dependent on temperature. But the most curious thing was that when the temperature changed by 10 Celsius, the volume of gas increased or decreased by the same amount. Having made the necessary calculations, Gay-Lussac found that this value was equal to 1/273 of the volume of the gas at a temperature of 0C.

This law led to the obvious conclusion: a temperature equal to -2730C is the lowest temperature, even if you come close to it, it is impossible to achieve it. It is this temperature that is called “absolute zero temperature.”

Moreover, absolute zero became the starting point for the creation of the absolute temperature scale, in which the English physicist W. Thomson, also known as Lord Kelvin, took an active part.

His main research concerned proving that no body in nature can be cooled below absolute zero. At the same time, he actively used the second one; therefore, the absolute temperature scale he introduced in 1848 began to be called the thermodynamic or “Kelvin scale.”

In subsequent years and decades, there was only a numerical clarification of the concept of “absolute zero”, which, after numerous agreements, began to be considered equal to -273.150C.

It is also worth noting that absolute zero plays a very important role in The whole point is that in 1960, at the next General Conference on Weights and Measures, the unit of thermodynamic temperature - the kelvin - became one of the six basic units of measurement. At the same time, it was specially stipulated that one degree Kelvin is numerically equal to one, but the reference point “according to Kelvin” is usually considered to be absolute zero, that is, -273.150C.

The main physical meaning of absolute zero is that, according to the basic physical laws, at this temperature the energy of motion elementary particles, such as atoms and molecules, is equal to zero, and in this case any chaotic movement of these same particles should stop. At a temperature equal to absolute zero, atoms and molecules must take a clear position at the main points of the crystal lattice, forming an ordered system.

Nowadays, using special equipment, scientists have been able to obtain temperatures that are only a few parts per million above absolute zero. It is physically impossible to achieve this value itself due to the second law of thermodynamics described above.