What temperature is called absolute zero? Absolute zero temperature

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: on the temperature of the phase transition 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 after 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.

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.

Zero and zero noun, m., used. compare often Morphology: (no) what? zero and zero, why? zero and zero, (see) what? zero and zero, what? zero and zero, what about? about zero, zero; pl. What? zeros and zeros, (no) what? zeros and zeros, why? zeros and zeros, (I see)… … Dmitriev's Explanatory Dictionary

Absolute zero (zero). Razg. Neglected 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

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 awaits him ahead?...

Have you ever thought about how low 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 curious people.

What is absolute zero

Even if you didn’t like physics since childhood, you are probably familiar with 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 -273.15 degrees Celsius. This value is called absolute zero. In other words, this is the minimum possible limit to which the physical body can be cooled. There is even an absolute temperature scale (Kelvin scale), in which absolute zero is the reference point, and one division of the scale is equal to one degree. Scientists around the world do not stop working to achieve this value, as this promises enormous prospects for humanity.

Why is this so important

Extremely low and extremely high temperatures are closely related to the concepts of superfluidity and superconductivity. The disappearance of electrical resistance in superconductors will make it possible to achieve unimaginable efficiency values and eliminate any energy losses. If we could find a way that would allow us to freely reach the value of “absolute zero,” many of humanity’s problems would be solved. Trains hovering above the rails, lighter and smaller engines, transformers and generators, high-precision magnetoencephalography, high-precision watches - these are just a few examples of what superconductivity can bring to our lives.

Latest Scientific Advances

In September 2003, researchers from MIT and NASA were able to cool sodium gas to a record low. During the experiment, they were only half a billionth of a degree short of the finish line (absolute zero). During the tests, the sodium was constantly in a magnetic field, which kept it from touching the walls of the container. If it were possible to overcome the temperature barrier, molecular motion in the gas would completely stop, because such cooling would extract all the energy from the sodium. The researchers used a technique whose author (Wolfgang Ketterle) received the Nobel Prize in Physics in 2001. The key point in the tests was the gas processes of Bose-Einstein condensation. 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 now, absolute zero temperature remains unattainable for science, although scientists have been able to approach it to a negligible distance.

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 off 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.