Discussion

Amontons hypothesized a state devoid of heat in a paper published in 1703.

All systems in thermodynamic equilibrium at absolute zero have vanishing entropy. This principle is called the Nernst heat theorem, or. the third law of thermodynamics. Walther Hermann Nernst (1864-1941) Germany.

It is impossible reduce the temperature of any systems to absolute zero in a finite number of steps.

The Laws of Thermodynamics

0. There is a game.
1. You can't win.
2. You must lose.
3. You can't quit. (Alternate: You can't cheat.)

Cryogenic Milestones
date	kelvin temperature	event
1724	233	Cascade series Gabriel Fahrenheit, Holland
1834	163	Mixture of dry ice, snow, and ether Charles Thilorier, Paris
1877	133	Droplets of liquid oxygen Raoul Pictet, Geneva / Louis Cailletet, Paris
1883	90	Measurable quantity of liquid oxygen Zygmunt Wróblewski & Karol Olszewski, Kraków
1886	54	Oxygen solidified James Dewar, Robert Lennox & James Heath, London
1898	21	Hydrogen liquefied James Dewar, Robert Lennox & James Heath, London
1899	14	Hydrogen solidified James Dewar, Robert Lennox & James Heath, London
1908	4	Helium liquefied Kamerlingh Onnes, Leiden
1908	1	Evaporation of liquid helium Kamerlingh Onnes, Leiden
1926	0.95	Helium solidified under 26 atm pressure Willem Keesom, Leiden
1933	0.53 / 0.27	Adiabatic demagnetization of paramagnetic salts William Giauque, Berkeley / Wander de Haas, Leiden
1956	16 × 10−6	Adiabatic nuclear demagnetization  Franz Simon & Miklós Kürti, Oxford
1970s	????	???? ????
1980s	????	???? ????
1993   1999   2000	280 × 10−12 250 × 10−12 100 × 10−12	Adiabatic nuclear demagnetization of rhodium Helsinki University of Technology

Onnes' helium liquefaction cascade: chloromethane, ethylene, oxygen, liquid air, hydrogen, helium. Onnes had a monopoly on the production of liquid helium

William Francis Giauque & Peter Joseph William Debye, adiabatic demagnetization of paramagnetic salts: iron ammonium alum, chromium potassium alum, cerium magnesium nitrate

superconductivity

superfluidity