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Federal State Budgetary Educational Institution of Higher Professional Education
"Voronezh State Pedagogical University"
Department of General Physics
on the topic: "Absolute zero temperature"
Completed by: 1st year student, FMF,
PI, Kondratenko Irina Alexandrovna
Checked by: Assistant of the Department of General
physicists Afonin G.V.
Voronezh-2013
Introduction………………………………………………………. 3
1.Absolute zero…………………………………………...4
2.History……………………………………………………… 6
3. Phenomena observed near absolute zero………..9
Conclusion……………………………………………………… 11
List of used literature…………………………..12
Introduction
For many years, researchers have been attacking the absolute zero temperature. As you know, the temperature equal to absolute zero characterizes the ground state of a system of many particles - the state with the lowest possible energy, at which atoms and molecules perform the so-called "zero" vibrations. Thus, deep cooling close to absolute zero (it is believed that absolute zero itself is unattainable in practice) opens up unlimited possibilities for studying the properties of matter.
1. Absolute zero
Absolute zero temperature (more rarely - absolute zero temperature) - the minimum temperature limit that a physical body in the Universe. Absolute zero is the starting point for 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 is taken to be 273.16 K (exactly), which corresponds to 0.01 ° C, so that on the Celsius scale absolute zero corresponds to temperature -273.15°C.
In the framework of the applicability of thermodynamics, absolute zero is unattainable in practice. Its existence and position on the temperature scale follows from the extrapolation of the observed physical phenomena, while such extrapolation shows that at absolute zero the energy of the thermal motion of molecules and atoms of a substance must be equal to zero, that is, the chaotic motion of particles stops, and they form an ordered structure, occupying clear position in the nodes crystal lattice(liquid helium is an exception). However, from the point of view of quantum physics, even at absolute zero temperature, there are zero fluctuations, which are due to the quantum properties of particles and the physical vacuum surrounding them.
As the temperature of the system tends to absolute zero, its entropy, heat capacity, thermal expansion coefficient also tend to zero, and the chaotic motion of the particles that make up the system stops. In a word, matter becomes supersubstance with superconductivity and superfluidity.
The absolute zero temperature is unattainable in practice, and obtaining temperatures approaching it as close as possible is a complex experimental problem, but temperatures have already been obtained that are only millionths of a degree away from absolute zero. .
Let us find the value of absolute zero on the Celsius scale by equating the volume V to zero and taking into account that
Hence the absolute zero temperature is -273°C.
This is the limiting, lowest temperature in nature, that “greatest or last degree of cold”, the existence of which Lomonosov predicted.
Fig.1. Absolute scale and Celsius scale
Unit absolute temperature in the SI system is called kelvin (abbreviated as K). Therefore, one degree Celsius is equal to one degree Kelvin: 1 °C = 1 K.
Thus, the absolute temperature is a derivative 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 the molecular kinetic theory, the absolute temperature is related to the average kinetic energy of the random motion of atoms or molecules. At T = 0 K, the thermal motion of molecules stops.
2. History
The physical concept of "absolute zero temperature" is very important for modern science: such a concept as superconductivity, the discovery of which made a splash in the second half of the 20th century, is closely related to it.
To understand what absolute zero is, one should refer to the works of such famous physicists as G. Fahrenheit, A. Celsius, J. Gay-Lussac and W. Thomson. It was they who played a key role in the creation of the main temperature scales still used today.
The first to offer his own temperature scale in 1714 was the German physicist G. Fahrenheit. At the same time, the temperature of the mixture, which included snow and ammonia, was taken as absolute zero, that is, the lowest point on this scale. The next important indicator was the normal temperature of the human body, which began to equal 1000. Accordingly, each division of this scale was called the “degree Fahrenheit”, and the scale itself was called the “Fahrenheit scale”.
After 30 years, the Swedish astronomer A. Celsius proposed his own temperature scale, where the main points were the melting temperature of ice and the boiling point of 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 mass of 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 the 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 gas. From this law, the obvious conclusion followed: the temperature equal to -273 ° C is the lowest temperature, even approaching which it is impossible to reach it. This temperature is called "absolute zero temperature". Moreover, absolute zero became the starting point for creating the absolute temperature scale, in which the English physicist W. Thomson, also known as Lord Kelvin, took an active part. His main research concerned the proof that no body in nature can be cooled below absolute zero. At the same time, he actively used the second law of thermodynamics, therefore, introduced by him in 1848 absolute scale temperature became known as the thermodynamic or “Kelvin scale.” In subsequent years and decades, only a numerical refinement of the concept of “absolute zero” took place.
Fig.2. Relationship between Fahrenheit (F), Celsius (C) and Kelvin (K) temperature scales.
It is also worth noting that absolute zero plays a very important role in the SI system. The thing is that in 1960 at the next General Conference on Weights and Measures, the unit of thermodynamic temperature - kelvin - became one of the six basic units of measurement. At the same time, it was specifically stipulated that one degree Kelvin
is numerically equal to one degree Celsius, only here the reference point "according to Kelvin" is considered to be absolute zero.
The main physical meaning of absolute zero is that, according to the basic physical laws, at such a 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 should take a clear position in the main points of the crystal lattice, forming an ordered system.
Currently, using special equipment, scientists have been able to obtain a temperature only a few millionths higher than absolute zero. It is physically impossible to achieve this value itself because of the second law of thermodynamics.
3. Phenomena observed near absolute zero
At temperatures close to absolute zero, purely quantum effects can be observed at the macroscopic level, such as:
1. Superconductivity - the property of some materials to have strictly zero electrical resistance when they reach a temperature below a certain value (critical temperature). Several hundreds of compounds, pure elements, alloys and ceramics are known that pass into the superconducting state.
Superconductivity is a quantum phenomenon. It is also characterized by the Meissner effect, which consists in the complete displacement of the magnetic field from the bulk of the superconductor. The existence of this effect shows that superconductivity cannot be described simply as ideal conductivity in the classical sense. Opening in 1986-1993 a number of high-temperature superconductors (HTSCs) pushed far the temperature limit of superconductivity and allowed the practical use of superconducting materials not only at the temperature of liquid helium (4.2 K), but also at the boiling point of liquid nitrogen (77 K), a much cheaper cryogenic liquid.
2. Superfluidity - the ability of a substance in a special state (quantum liquid), which occurs when the temperature drops to absolute zero (thermodynamic phase), to flow through narrow slots and capillaries without friction. Until recently, superfluidity was known only for liquid helium, but in last years superfluidity was also discovered in other systems: in rarefied atomic Bose condensates, solid helium.
Superfluidity is explained as follows. Since helium atoms are bosons, quantum mechanics allows an arbitrary number of particles to be in the same state. Near absolute zero temperatures, all helium atoms are in the ground energy state. Since the energy of the states is discrete, an atom can receive not any energy, but only one that is equal to the energy gap between adjacent energy levels. But at low temperatures, the collision energy may be less than this value, as a result of which energy dissipation simply will not occur. The fluid will flow without friction.
3. The Bose-Einstein condensate is an aggregate state of matter, which is based on bosons cooled to temperatures close to absolute zero (less than a millionth of a degree above absolute zero). In such a highly chilled state, it is enough big number atoms are in their lowest possible quantum states and quantum effects begin to manifest themselves at the macroscopic level.
Conclusion
The study of the properties of matter near absolute zero is of great interest to science and technology.
Many properties of a substance, veiled at room temperature by thermal phenomena (for example, thermal noise), begin to manifest themselves more and more as the temperature decreases, allowing one to study in its pure form the regularities and relationships inherent in a given substance. Research in the field of low temperatures made it possible to discover many new natural phenomena, such as, for example, the superfluidity of helium and the superconductivity of metals.
At low temperatures, the properties of materials change dramatically. Some metals increase their strength, become ductile, others become brittle, like glass.
The study of physicochemical properties at low temperatures will make it possible in the future to create new substances with predetermined properties. All this is very valuable for the design and construction of spacecraft, stations and instruments.
It is known that during radar studies of cosmic bodies, the received radio signal is very small and it is difficult to distinguish it from various noises. Molecular oscillators and amplifiers recently created by scientists operate at very low temperatures and therefore have a very low noise level.
The low-temperature electrical and magnetic properties of metals, semiconductors and dielectrics make it possible to develop fundamentally new radio engineering devices of microscopic dimensions.
Extremely low temperatures are used to create the vacuum required, for example, for the operation of giant nuclear particle accelerators.
Bibliography
- http://wikipedia.org
- http://rudocs.exdat.com
- http://fb.ru
Short description
For many years, researchers have been attacking the absolute zero temperature. As you know, the temperature equal to absolute zero characterizes the ground state of a system of many particles - the state with the lowest possible energy, at which atoms and molecules perform the so-called "zero" vibrations. Thus, deep cooling close to absolute zero (it is believed that absolute zero itself is unattainable in practice) opens up unlimited possibilities for studying the properties of matter.
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 the extrapolation of the observed physical phenomena, while such extrapolation shows that at absolute zero the energy of the thermal motion of molecules and atoms of a substance must be equal to zero, that is, the chaotic motion of particles stops, and they form an ordered structure, occupying a 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 fluctuations, such as zero-point vibrations, are due to the quantum properties of the particles and the physical vacuum that surrounds them.
At present, physical laboratories have been able to obtain temperatures exceeding absolute zero by only a few millionths of a degree; it is impossible to achieve it, according to the laws of thermodynamics.
Notes
Literature
- G. Burmin. Storming absolute zero. - M .: "Children's literature", 1983.
see also
Wikimedia Foundation. 2010 .
Synonyms: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 ... ... encyclopedic Dictionary
Temperatures, the origin of the 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 practically been reached, ... ... Modern Encyclopedia
Temperatures are the origin of the temperature reading on the thermodynamic temperature scale. Absolute zero is located 273.16.C below the temperature of the triple point of water, for which the value of 0.01.C is accepted. Absolute zero is fundamentally unattainable (see ... ... Big Encyclopedic Dictionary
The temperature expressing the absence of heat is 218 ° C. Vocabulary foreign words included in the Russian language. Pavlenkov F., 1907. absolute zero temperature (phys.) – the lowest possible temperature (273.15°C). Large dictionary ... ... Dictionary of foreign words of the Russian language
absolute zero- The extremely low temperature at which the thermal movement of molecules stops, in the Kelvin scale absolute zero (0°K) corresponds to -273.16 ± 0.01°C ... Geography Dictionary
Exist., number of synonyms: 15 round zero (8) little man (32) small fry ... Synonym dictionary
Extremely low temperature at which the thermal movement of molecules stops. pressure and volume ideal gas, according to Boyle's Mariotte's law, becomes equal to zero, and the reference point for the absolute temperature on the Kelvin scale is taken ... ... Ecological dictionary
absolute zero- - [A.S. Goldberg. English Russian Energy Dictionary. 2006] Topics energy in general EN zeropoint … Technical Translator's Handbook
Absolute temperature reference point. Corresponds to 273.16 ° C. At present, in physical laboratories, it was possible to obtain a temperature exceeding absolute zero by only a few millionths of a degree, but to achieve it, according to the laws ... ... Collier 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 aiskinamasis 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 aiskinamasis žodynas
Where do you think the coldest place in our universe is located? Today it is Earth. For example, the surface temperature of the moon is -227 degrees Celsius, and the temperature of the vacuum that surrounds us is 265 degrees below zero. However, in a laboratory on Earth, a person can achieve temperatures much lower in order to study the properties of materials in ultra-low temperatures. Materials, individual atoms, and even light subjected to extreme cooling begin to exhibit unusual properties.
The first experiment of this kind was carried out at the beginning of the 20th century by physicists who studied electrical properties mercury at low temperatures. At -262 degrees Celsius, mercury begins to exhibit the properties of superconductivity, reducing the resistance to electric current to almost zero. Further experiments also revealed other interesting properties of cooled materials, including superfluidity, which is expressed in the "leakage" of matter through solid partitions and out of closed containers.
Science has determined the lowest achievable temperature - minus 273.15 degrees Celsius, but practically such a temperature is unattainable. In practice, temperature is an approximate measure of the energy contained in an object, so absolute zero indicates that the body does not radiate anything, and no energy can be extracted from this object. But despite this, scientists are trying to get as close as possible to absolute zero temperature, the current record was set in 2003 in the laboratory of the Massachusetts Institute of Technology. Scientists were only 810 billionths of a degree short of absolute zero. They cooled a cloud of sodium atoms held in place by a powerful magnetic field.
It would seem - what is the applied meaning of such experiments? It turns out that researchers are interested in such a concept as a Bose-Einstein condensate, which is a special state of matter - not a gas, solid or liquid, but simply a cloud of atoms with the same quantum state. This form of matter was predicted by Einstein and the Indian physicist Satyendra Bose in 1925, and was obtained only 70 years later. One of the scientists who achieved this state of matter is Wolfgang Ketterle, who received Nobel Prize in the field of physics.
One of the remarkable properties of the Bose-Einstein Condensate (BEC) is the ability to control the movement of light rays. In a vacuum, light travels at 300,000 km per second, which is the fastest speed achievable in the universe. But light can propagate more slowly if it propagates not in a vacuum, but in matter. With the help of BEC, it is possible to slow down the movement of light to low speeds, and even stop it. Due to the temperature and density of the condensate, the light emission slows down and can be "captured" and converted directly into electricity. This current can be transferred to another BEC cloud and converted back into light radiation. This feature is in great demand for telecommunications and computing. Here I don’t understand a little - after all, devices that convert light waves into electricity and vice versa ALREADY exists... Apparently, the use of BEC allows this conversion to be carried out faster and more accurately.
One of the reasons why scientists are so eager to get an absolute zero is an attempt to understand what is happening and has happened to our Universe, what thermodynamic laws operate in it. At the same time, researchers understand that extracting all the energy to the last from the atom is practically unattainable.
Absolute zero temperature
Absolute zero temperature is the minimum temperature limit that a physical body can have. Absolute zero serves as the reference point for an absolute temperature scale, such as the Kelvin scale. On the Celsius scale, absolute zero corresponds to -273.15 °C.
It is believed that absolute zero is unattainable in practice. Its existence and position on the temperature scale follows from the extrapolation of the observed physical phenomena, while such extrapolation shows that at absolute zero the energy of the thermal motion of molecules and atoms of a substance must be equal to zero, that is, the chaotic motion of particles stops, and they form an ordered structure, occupying a 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 fluctuations, such as zero-point vibrations, are due to the quantum properties of the particles and the physical vacuum that surrounds them.
At present, physical laboratories have been able to obtain temperatures exceeding absolute zero by only a few millionths of a degree; it is impossible to achieve it, according to the laws of thermodynamics.
Notes
Literature
- G. Burmin. Storming absolute zero. - M .: "Children's literature", 1983.
see also
Wikimedia Foundation. 2010 .
- Absolute zero temperature
- Absolute zero temperature
See what "Absolute Zero Temperature" is in other dictionaries:
Absolute zero temperature- Absolute zero temperature is the minimum temperature limit that a physical body can have. Absolute zero is the starting point for an absolute temperature scale, such as the Kelvin scale. On the Celsius scale, absolute zero corresponds to ... ... Wikipedia
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... Scientific and technical encyclopedic dictionary
Absolute temperature scale
Absolute thermodynamic temperature- Chaotic thermal motion on the plane of gas particles such as atoms and molecules There are two definitions of temperature. One from a molecular kinetic point of view, the other from a thermodynamic point of view. Temperature (from Latin temperatura proper ... ... Wikipedia
Absolute temperature scale- Chaotic thermal motion on the plane of gas particles such as atoms and molecules There are two definitions of temperature. One from a molecular kinetic point of view, the other from a thermodynamic point of view. Temperature (from Latin temperatura proper ... ... Wikipedia
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 for doing useful work - is also 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:
Temperatures are the minimum temperature limit that a physical body can have. Absolute zero is 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 origin 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 almost unattainable ... Great Polytechnic Encyclopedia
This is the minimum temperature limit that a physical body can have. Absolute zero is 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 is 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. FSRYA, 288; BTS, 24; ZS 1996, 33 ...
zero- absolute zero … Dictionary of Russian Idioms
Zero and zero n., m., use. comp. often Morphology: (no) what? zero and zero, why? zero and zero, (see) what? zero and zero, what? zero and zero, about what? about zero, zero; pl. what? zeros and zeros, (no) what? zeros and zeros, why? zeros and zeros, (I see) ... ... Dictionary Dmitrieva
Absolute zero (zero). Razg. Neglect An insignificant, insignificant person. FSRYA, 288; BTS, 24; ZS 1996, 33 To zero. 1. Jarg. they say Shuttle. iron. About severe intoxication. Yuganov, 471; Vakhitov 2003, 22. 2. Jarg. music Exactly, in full accordance with ... ... Big 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 lies ahead for him?...
