Any measurement requires a reference point. Temperature is no exception. For the Fahrenheit scale, this zero point is the temperature of the snow mixed with table salt, for the Celsius scale - the freezing point 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 to the external environment during heat transfer. In this case, the body temperature decreases, i.e. there is less energy left. Theoretically, this process can continue until the amount of energy reaches such a minimum at which 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" motion. Therefore, the limiting degree of cooling is a complete stop of such movement. According to modern ideas, absolute zero temperature is a state of matter in which the molecules are at 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 the conditions of scientific laboratories with the most sophisticated equipment. But scientists manage to cool matter to very low temperatures, which are close to absolute zero. At such temperatures, substances acquire amazing properties that they cannot have under normal circumstances. Mercury, called "living silver" because of its near-liquid state, becomes solid at this temperature, to the point where it can hammer nails. Some metals become brittle, like glass. Rubber becomes hard and brittle. If, at a temperature close to absolute zero, you hit a rubber object with a hammer, it will break like glass. Such a 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 ordered. So the gas becomes a liquid, and the liquid becomes a solid. The limiting level of order is the crystal structure. At ultralow temperatures, even substances that remain amorphous in their normal state, such as rubber, acquire it. Interesting phenomena also occur with metals. The atoms of the crystal lattice vibrate with a smaller amplitude, the scattering of electrons decreases, therefore, the electrical resistance decreases. The metal acquires superconductivity, practical use which seems very tempting, although difficult to achieve.The science
Until recently, the coldest temperature that a physical body could have was the temperature of "absolute zero" on the Kelvin scale. It corresponds −273.15 degrees Celsius or −460 degrees Fahrenheit.
Now physicists from Germany have been able to reach temperatures below absolute zero. Such a discovery will help scientists understand phenomena such as dark energy and create new forms of matter.
Absolute zero temperature
In the middle of the 19th century, the British physicist Lord Kelvin created the absolute temperature scale and determined that nothing can be colder than absolute zero. When particles are at absolute zero temperature, they stop moving and have no energy.
The temperature of an object is a measure of how much the atoms are moving. The colder the object, the slower the atoms move. At absolute zero, or -273.15 degrees Celsius, atoms stop moving.
In the 1950s, physicists began to argue that particles don't always lose energy at absolute zero.
Scientists from Ludwig Maximilian University in Munich and Max Planck Institute for Quantum Optics in Garching created a gas that became colder than absolute zero by a few nanokelvins.
They cooled about 100,000 atoms to a positive temperature of a few nanokelvins (a nanokelvin is one billionth of a kelvin) and used a network of laser beams and magnetic fields to control the behavior of the atoms and push them to a new temperature limit.
highest temperature
If the lowest possible temperature is considered absolute zero, then what temperature can be considered its opposite - the highest temperature? According to cosmological models, the highest possible temperature is the Planck temperature, which corresponds to 1.416785(71)x1032 kelvins (141 nonillion 679 octillion degrees).
Our Universe has already passed through the Planck temperature. This happened 10^-42 seconds after big bang when the universe was born.
The lowest temperature on Earth
The lowest temperature on Earth was recorded on July 21, 1983 at Vostok station in Antarctica, and it was -89.2 degrees Celsius.
Vostok Station is the coldest permanent inhabited place on Earth. It was founded by Russia in 1957 and is located at an altitude of 3488 meters above sea level.
The highest temperature on Earth
The highest temperature on Earth was recorded on July 10, 1913 in Death Valley in California and it was 56.7 degrees Celsius.
The previous record for the highest temperature in the world in the city of Al Aziziyah in Libya, which amounted to 57.7 degrees Celsius, was refuted World Meteorological Organization because of the unreliability of the data.
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
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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. Dictionary of foreign words included in the Russian language. Pavlenkov F., 1907. absolute zero temperature (phys.) – 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, 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) small man(32) small fry ... Synonym dictionary
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 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
Have you ever thought about how cold the temperature can be? What is absolute zero? Will humanity ever be able to achieve it and what opportunities will open up after such a discovery? These and other similar questions have long occupied the minds of many physicists and simply inquisitive people.
What is absolute zero
Even if you didn’t like physics since childhood, you probably know the concept of temperature. Thanks to the molecular kinetic theory, we now know that there is a certain static connection between it and the movements of molecules and atoms: the higher the temperature of any physical body, the faster its atoms move, and vice versa. The question arises: "Is there such a lower limit at which elementary particles will freeze in place?". Scientists believe that this is theoretically possible, the thermometer will be at around -273.15 degrees Celsius. This value is called absolute zero. In other words, this is the minimum possible limit to which a physical body can be cooled. There is even an absolute temperature scale (the Kelvin scale), in which absolute zero is the reference point, and a unit division of the scale is equal to one degree. Scientists around the world do not stop working to achieve this value, as this promises great prospects for humanity.
Why is it so important
Extremely low and extremely high temperatures are closely related to the concept of superfluidity and superconductivity. The disappearance of electrical resistance in superconductors will make it possible to achieve unthinkable values of efficiency and eliminate any energy losses. If it were possible to find a way that would allow one to freely reach the value of "absolute zero", many of the problems of mankind would be solved. Trains hovering over the rails, lighter and smaller engines, transformers and generators, high-precision magnetoencephalography, high-precision clocks are just a few examples of what superconductivity can bring to our lives.
Latest scientific achievements
In September 2003, researchers from MIT and NASA managed to cool sodium gas to an all-time low. During the experiment, they were only half a billionth of a degree short of the finish line (absolute zero). During the tests, sodium was always in a magnetic field, which kept it from touching the walls of the container. If it were possible to overcome the temperature barrier, the molecular movement in the gas would completely stop, because such cooling would extract all the energy from sodium. The researchers applied the technique, the author of which (Wolfgang Ketterle) received in 2001 Nobel Prize in physics. The key point in the tests carried out were the gaseous Bose-Einstein condensation processes. Meanwhile, no one has yet canceled the third law of thermodynamics, according to which absolute zero is not only an insurmountable, but also an unattainable value. In addition, the Heisenberg uncertainty principle applies, and atoms simply cannot stop dead in their tracks. Thus, for the time being, the absolute zero temperature for science remains unattainable, although scientists have been able to approach it at a negligibly small distance.
The physical concept of "absolute zero temperature" has for modern science very important: 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 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 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 mass 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 at a temperature equal to 0C.
The obvious conclusion followed from this law: the temperature equal to -2730C 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 one, therefore, the absolute temperature scale introduced by him in 1848 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, which, after numerous agreements, began to be considered equal to -273.150С.
It is also worth noting that absolute zero plays a very important role 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, only here the reference point “according to Kelvin” is considered to be absolute zero, that is, -273.150С.
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 very 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 described above.
