Any physical body, including all objects in the Universe, has a minimum temperature or its limit. The starting point of any temperature scale is considered to be the value of absolute zero temperature. But this is only in theory. The chaotic movement of atoms and molecules, which give up their energy at this time, has not yet been stopped in practice.
This is the main reason why absolute zero temperatures cannot be reached. There are still debates about the consequences of this process. From the point of view of thermodynamics, this limit is unattainable, since the thermal movement of atoms and molecules stops completely, and a crystal lattice is formed.
Representatives of quantum physics envision the presence of minimum zero oscillations at absolute zero temperatures.
What is the value of absolute zero temperature and why it cannot be achieved
At the General Conference on Weights and Measures, a reference or reference point was established for the first time for measuring instruments that determine temperature indicators.
Currently, in the International System of Units, the reference point for the Celsius scale is 0°C for freezing and 100°C for boiling, the value of absolute zero temperatures is equal to −273.15°C.
Using temperature values on the Kelvin scale according to the same International System of Units, boiling of water will occur at the reference value of 99.975 ° C, absolute zero is equal to 0. On the Fahrenheit scale the indicator corresponds to -459.67 degrees.
But, if these data are obtained, why then is it impossible to achieve absolute zero temperatures in practice? For comparison, we can take the well-known speed of light, which is equal to the constant physical value of 1,079,252,848.8 km/h.
However, this value cannot be achieved in practice. It depends on the transmission wavelength, the conditions, and the required absorption of a large amount of energy by the particles. To obtain the value of absolute zero temperatures, a large output of energy is required and the absence of its sources to prevent it from entering atoms and molecules.
But even in conditions of complete vacuum, scientists were unable to obtain either the speed of light or absolute zero temperatures.
Why is it possible to reach approximately zero temperatures, but not absolute zero?
What will happen when science can come close to achieving the extremely low temperature of absolute zero remains only in the theory of thermodynamics and quantum physics. What is the reason why absolute zero temperatures cannot be achieved in practice.
All known attempts to cool a substance to the lowest limit due to maximum energy loss led to the fact that the heat capacity of the substance also reached a minimum value. The molecules were simply no longer able to give up the remaining energy. As a result, the cooling process stopped without reaching absolute zero.
When studying the behavior of metals under conditions close to absolute zero temperatures, scientists found that a maximum decrease in temperature should provoke a loss of resistance.
But the cessation of the movement of atoms and molecules only led to the formation of a crystal lattice, through which passing electrons transferred part of their energy to stationary atoms. Again, it was not possible to reach absolute zero.
In 2003, the temperature was only half a billionth of 1°C short of absolute zero. NASA researchers used a Na molecule to conduct experiments, which was always in a magnetic field and gave up its energy.
The closest achievement was achieved by scientists at Yale University, who in 2014 achieved a figure of 0.0025 Kelvin. The resulting compound, strontium monofluoride (SrF), lasted only 2.5 seconds. And in the end it still disintegrated into atoms.
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 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
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
Science
Until recently, the coldest temperature a physical body could have was considered to be “absolute zero” on the Kelvin scale. This matches −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 mid-19th century, 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 do not always lose energy at absolute zero.
Scientists from Ludwig Maximilian University in Munich and Max Planck Institute for Quantum Optics gas was created in Garching, which became colder than absolute zero by several nanokelvins.
They cooled about 100,000 atoms to a 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 the Big Bang, when the Universe was born.
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 permanently inhabited place on Earth. It was founded by Russia in 1957 and is located at an altitude of 3488 meters above sea level.
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-Aziziya in Libya, amounting to 57.7 degrees Celsius, was refuted World Meteorological Organization due to unreliable data.
The term “temperature” appeared at a time when physicists thought that warm bodies consisted of more of a specific substance - caloric - than the same bodies, but cold ones. And temperature was interpreted as a value corresponding to the amount of caloric in the body. Since then, the temperature of any body has been measured in degrees. But in fact it is a measure of the kinetic energy of moving molecules, and, based on this, it should be measured in Joules, in accordance with the System of Units C.
The concept of “absolute zero temperature” comes from the second law of thermodynamics. According to it, the process of heat transfer from a cold body to a hot one is impossible. This concept was introduced by the English physicist W. Thomson. For his achievements in physics, he was given the title of nobility “Lord” and the title “Baron Kelvin”. In 1848, W. Thomson (Kelvin) proposed using a temperature scale in which he took absolute zero temperature, corresponding to extreme cold, as the starting point, and took degrees Celsius as the division value. The Kelvin unit is 1/27316 of the temperature of the triple point of water (about 0 degrees C), i.e. temperature at which pure water immediately exists in three forms: ice, liquid water and steam. temperature is the lowest possible low temperature at which the movement of molecules stops and it is no longer possible to extract thermal energy from a substance. Since then, the absolute temperature scale has been named after him.
Temperature is measured on different scales
The most commonly used temperature scale is called the Celsius scale. It is built on two points: the temperature of water from liquid to steam and water to ice. A. Celsius in 1742 proposed dividing the distance between reference points into 100 intervals, and taking water as zero, with the freezing point as 100 degrees. But the Swede K. Linnaeus suggested doing the opposite. Since then, water has frozen at zero degrees A. Celsius. Although it should boil exactly at Celsius. Absolute zero Celsius corresponds to minus 273.16 degrees Celsius.
There are several more temperature scales: Fahrenheit, Reaumur, Rankin, Newton, Roemer. They have different division prices. For example, the Reaumur scale is also built on the reference points of boiling and freezing of water, but it has 80 divisions. The Fahrenheit scale, which appeared in 1724, is used in everyday life only in some countries of the world, including the USA; one is the temperature of the mixture of water ice and ammonia and the other is the temperature of the human body. The scale is divided into one hundred divisions. Zero Celsius corresponds to 32 Conversion of degrees to Fahrenheit can be done using the formula: F = 1.8 C + 32. Reverse conversion: C = (F - 32)/1.8, where: F - degrees Fahrenheit, C - degrees Celsius. If you are too lazy to count, go to an online service for converting Celsius to Fahrenheit. In the box, enter the number of degrees Celsius, click "Calculate", select "Fahrenheit" and click "Start". The result will appear immediately.
Named in honor of the English (more precisely Scottish) physicist William J. Rankin, who was a contemporary of Kelvin and one of the creators of technical thermodynamics. There are three important points in his scale: the beginning is absolute zero, the freezing point of water is 491.67 degrees Rankine and the boiling point of water is 671.67 degrees. The number of divisions between the freezing of water and its boiling for both Rankine and Fahrenheit is 180.
Most of these scales are used exclusively by physicists. And 40% of American high school students surveyed today said that they do not know what absolute zero temperature is.
Even if you're not a physicist, you're probably familiar with the concept of temperature. But if you're unlucky enough to grow up in the forest or on another planet, here's a quick overview.
Temperature is a measure of the amount of internal random energy of a material. The word "internal" is very important. Throw a snowball, and although the main movement will be quite fast, the snowball will remain quite cold. On the other hand, if you look at air molecules flying around a room, an ordinary oxygen molecule is frying at thousands of kilometers per hour.
We usually stay quiet when it comes to technical details, so just for the experts, we'll point out that temperature is a little more complicated than we said. The true definition of temperature involves how much energy you need to expend for each unit of entropy (disorder, if you want a clearer word;). But let's skip the subtleties and just focus on the fact that random air or water molecules in the ice will move or vibrate slower and slower as the temperature drops.
Absolute zero is a temperature of -273.15 degrees Celsius, -459.67 Fahrenheit and simply 0 Kelvin. This is the point where thermal movement stops completely.
Does everything stop?
In the classical consideration of the issue, everything stops at absolute zero, but it is at this moment that the terrible face of quantum mechanics peeks out from around the corner. One of the predictions of quantum mechanics that has spoiled the blood is that you can never measure the exact position or momentum of a particle with perfect certainty. This is known as Heisenberg uncertainty principle.
If you could cool a sealed room to absolute zero, strange things would happen (more on that later). The air pressure would drop to almost zero, and since air pressure usually opposes gravity, the air would collapse into a very thin layer on the floor.
But even so, if you can measure individual molecules, you'll find something interesting: they vibrate and spin, just a little bit of quantum uncertainty at work. To dot the i's, if you measure the rotation of carbon dioxide molecules at absolute zero, you will find that oxygen atoms fly around the carbon at several kilometers per hour - much faster than you thought.
The conversation reaches a dead end. When we talk about the quantum world, movement loses its meaning. At these scales, everything is determined by uncertainty, so it's not that the particles are stationary, you just you'll never be able to measure them like this as if they were motionless.
How low can you go?
The pursuit of absolute zero essentially faces the same problems as . To reach the speed of light requires an infinite amount of energy, and reaching absolute zero requires the extraction of an infinite amount of heat. Both of these processes are impossible, if anything.
Despite the fact that we have not yet achieved the actual state of absolute zero, we are very close to it (although “very” in this case is a very loose concept; like a nursery rhyme: two, three, four, four and a half, four on a string, four by a hair's breadth, five). The coldest temperature ever recorded on Earth was recorded in Antarctica in 1983, at -89.15 degrees Celsius (184K).
Of course, if you want to cool down in a childish way, you need to dive into the depths of space. The entire universe is bathed in the remnants of radiation from the Big Bang, in the emptiest regions of space - 2.73 degrees Kelvin, which is little colder than the temperature of the liquid helium we were able to obtain on Earth a century ago.
But low-temperature physicists are using freeze rays to take the technology to a whole new level. It may surprise you to know that freeze rays take the form of lasers. But how? Lasers are supposed to burn.
Everything is true, but lasers have one feature - one might even say, the ultimate: all light is emitted at one frequency. Ordinary neutral atoms do not interact with light at all unless the frequency is precisely tuned. If an atom flies towards a light source, the light receives a Doppler shift and reaches a higher frequency. The atom absorbs less photon energy than it could. So if you tune the laser lower, fast-moving atoms will absorb light, and by emitting a photon in a random direction, they will lose a little energy on average. If you repeat the process, you can cool the gas to a temperature of less than one nanoKelvin, a billionth of a degree.
Everything takes on a more extreme tone. The world record for lowest temperature is less than one-tenth of a billion degrees above absolute zero. Devices that achieve this trap atoms in magnetic fields. “Temperature” depends not so much on the atoms themselves, but on the spin of atomic nuclei.
Now, to restore justice, we need to get a little creative. When we usually imagine something frozen to one billionth of a degree, you probably get a picture of even air molecules freezing in place. One can even imagine a destructive apocalyptic device that freezes the backs of atoms.
Ultimately, if you really want to experience low temperatures, all you have to do is wait. After about 17 billion years, the background radiation in the Universe will cool down to 1K. In 95 billion years the temperature will be approximately 0.01K. In 400 billion years, deep space will be as cold as the coldest experiment on Earth, and even colder after that. If you're wondering why the universe is cooling so quickly, say thank you to our old friends: entropy And dark energy. The universe is in acceleration mode, entering a period of exponential growth that will continue forever. Things will freeze very quickly.
What do we care?
All this, of course, is wonderful, and breaking records is also nice. But what's the point? Well, there are plenty of good reasons to understand the low temperatures, and not just as a winner.
The good folks at NIST, for example, would just like to make a cool clock. Time standards are based on things like the frequency of the cesium atom. If the cesium atom moves too much, it creates uncertainty in the measurements, which will eventually cause the clock to malfunction.
But more importantly, especially from a scientific perspective, materials behave crazy at extremely low temperatures. For example, just as a laser is made of photons that are synchronized with each other - at the same frequency and phase - so a material known as a Bose-Einstein condensate can be created. In it, all atoms are in the same state. Or imagine an amalgam in which each atom loses its individuality and the entire mass reacts as one null-super-atom.
At very low temperatures, many materials become superfluids, meaning they can have no viscosity at all, stack in ultra-thin layers, and even defy gravity to achieve a minimum of energy. Also, at low temperatures, many materials become superconducting, meaning there is no electrical resistance. capable of reacting to external magnetic fields in such a way as to completely cancel them inside the metal. As a result, you can combine cold temperature and a magnet and get something like levitation.
Why is there absolute zero, but not absolute maximum?
Let's look at the other extreme. If temperature is simply a measure of energy, then we can simply imagine atoms getting closer and closer to the speed of light. This can't go on forever, can it?
The short answer is: we don't know. It's possible that there literally is such a thing as infinite temperature, but if there is an absolute limit, the young universe provides some pretty interesting clues as to what it is. The highest temperature ever known (at least in our universe) probably occurred during what is known as Planck's time. It was a moment 10^-43 seconds after the Big Bang when gravity separated from quantum mechanics and physics became exactly what it is now. The temperature at that time was approximately 10^32 K. This is a septillion times hotter than the inside of our Sun.
Again, we're not at all sure if this is the hottest temperature it could be. Since we don't even have a large model of the universe at Planck's time, we're not even sure the universe boiled to such a state. In any case, we are many times closer to absolute zero than to absolute heat.