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Temperature
The lowest temperature is 0 °K, the highest temperature is ≈ 1,4 · 1032 °K.
Explanation
The temperature can drop below 0 degrees. We're talking about 0 °C, from Celsius. It can be much colder, and the lowest temperature is −273.15 °C. That is called 0 °K, from Kelvin. Lower is not possible. It is said that at that temperature the atoms no longer move. Even time then stands still and has no meaning anymore.
According to the laws of thermodynamics you cannot reach 0 °K by cooling further and further. Yet physicists have approached it by only thousandths. For quantum systems in quasi-equilibrium (e.g., spins out of equilibrium with the electromagnetic field), negative temperatures are achievable.
There is apparently a highest temperature. Several million degrees are not uncommon. On the sun it is pretty hot, but it could be worse. Nevertheless ∞ °K has no meaning.
HistoryThe German mathematician Max Planck described that entropy is zero at absolute zero. The German chemist Walther Nernst formulated the third law of thermodynamics in 1905 as a consequence of this. |