Coldest temperature achieved on Earth
Encyclopedia
The lowest temperature ever recorded at the surface of the Earth
was −89.2 C at the Russian Vostok Station
in Antarctica July 21, 1983. Lower temperatures have been achieved in the laboratory, including a record low temperature of 100 pK, or 1.0 × 10-10 K in 1999.
created a special lab in Leiden with the aim of producing liquid helium
. In 1908 he managed to lower the temperature to less than four degrees above absolute zero
, to less than −269 °C (3 Kelvin). Only in this exceptionally cold state will helium liquefy, the boiling point of helium being at −268.94 °C. Kamerlingh Onnes received a Nobel Prize
for his achievement.
Onnes method relied upon depressurising the subject gases, causing them to cool. This follows from the first law of thermodynamics;
where U = internal energy
, Q = heat
added to the system, W = work
done by the system.
Consider a gas in a box of set volume. If the pressure in the box is higher than atmospheric pressure, then upon opening the box our gas will do work on the surrounding atmosphere to expand. As this expansion is adiabatic
and the gas has done work
Now as the internal energy has decreased so has the temperature.
's Low Temperature Lab. However, this was the temperature of one particular type of motion—a quantum property called nuclear spin—not the overall average thermodynamic temperature for all possible degrees of freedom. At such low temperatures, the concept of "temperature
" becomes multifaceted since molecular motion cannot be assumed to average out across degrees of freedom.
The current apparatus for achieving low temperatures has two stages. The first utilizes a helium dilution refrigerator
to get to temperatures of millikelvins, then the next stage uses adiabatic nuclear demagnetisation to reach picokelvins.
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
was −89.2 C at the Russian Vostok Station
Vostok Station
Vostok Station was a Russian Antarctic research station. It was at the southern Pole of Cold, with the lowest reliably measured natural temperature on Earth of −89.2 °C . Research includes ice core drilling and magnetometry...
in Antarctica July 21, 1983. Lower temperatures have been achieved in the laboratory, including a record low temperature of 100 pK, or 1.0 × 10-10 K in 1999.
Early cooling
In 1904 Dutch scientist Heike Kamerlingh OnnesHeike Kamerlingh Onnes
Heike Kamerlingh Onnes was a Dutch physicist and Nobel laureate. He pioneered refrigeration techniques, and he explored how materials behaved when cooled to nearly absolute zero. He was the first to liquify helium...
created a special lab in Leiden with the aim of producing liquid helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...
. In 1908 he managed to lower the temperature to less than four degrees above absolute zero
Absolute zero
Absolute zero is the theoretical temperature at which entropy reaches its minimum value. The laws of thermodynamics state that absolute zero cannot be reached using only thermodynamic means....
, to less than −269 °C (3 Kelvin). Only in this exceptionally cold state will helium liquefy, the boiling point of helium being at −268.94 °C. Kamerlingh Onnes received a Nobel Prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
for his achievement.
Onnes method relied upon depressurising the subject gases, causing them to cool. This follows from the first law of thermodynamics;
where U = internal energy
Internal energy
In thermodynamics, the internal energy is the total energy contained by a thermodynamic system. It is the energy needed to create the system, but excludes the energy to displace the system's surroundings, any energy associated with a move as a whole, or due to external force fields. Internal...
, Q = heat
Heat
In physics and thermodynamics, heat is energy transferred from one body, region, or thermodynamic system to another due to thermal contact or thermal radiation when the systems are at different temperatures. It is often described as one of the fundamental processes of energy transfer between...
added to the system, W = work
Work (thermodynamics)
In thermodynamics, work performed by a system is the energy transferred to another system that is measured by the external generalized mechanical constraints on the system. As such, thermodynamic work is a generalization of the concept of mechanical work in mechanics. Thermodynamic work encompasses...
done by the system.
Consider a gas in a box of set volume. If the pressure in the box is higher than atmospheric pressure, then upon opening the box our gas will do work on the surrounding atmosphere to expand. As this expansion is adiabatic
Adiabatic process
In thermodynamics, an adiabatic process or an isocaloric process is a thermodynamic process in which the net heat transfer to or from the working fluid is zero. Such a process can occur if the container of the system has thermally-insulated walls or the process happens in an extremely short time,...
and the gas has done work
Now as the internal energy has decreased so has the temperature.
Modern cooling
As of November 2000, nuclear spin temperatures below 100 pK were reported for an experiment at the Aalto UniversityAalto University
Aalto University is a Finnish university established on January 1, 2010, by the merger of the Helsinki University of Technology, the Helsinki School of Economics, and the University of Art and Design Helsinki....
's Low Temperature Lab. However, this was the temperature of one particular type of motion—a quantum property called nuclear spin—not the overall average thermodynamic temperature for all possible degrees of freedom. At such low temperatures, the concept of "temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
" becomes multifaceted since molecular motion cannot be assumed to average out across degrees of freedom.
The current apparatus for achieving low temperatures has two stages. The first utilizes a helium dilution refrigerator
Dilution refrigerator
A dilution refrigerator is a cryogenic device first proposed by Heinz London. Its refrigeration process uses a mixture of two isotopes of helium: helium-3 and helium-4...
to get to temperatures of millikelvins, then the next stage uses adiabatic nuclear demagnetisation to reach picokelvins.
See also
- Absolute zeroAbsolute zeroAbsolute zero is the theoretical temperature at which entropy reaches its minimum value. The laws of thermodynamics state that absolute zero cannot be reached using only thermodynamic means....
- Timeline of low-temperature technologyTimeline of low-temperature technologyThe following is a timeline of low-temperature technology and cryogenic technology .-16th century BCE – 17th century CE :...
- Dilution refrigeratorDilution refrigeratorA dilution refrigerator is a cryogenic device first proposed by Heinz London. Its refrigeration process uses a mixture of two isotopes of helium: helium-3 and helium-4...
- Adiabatic demagnetization
- Details of HUT experiment, including details of the cryostat