This is the coldest place on Earth under natural conditions.? The coldest place on >Earth was in a physics experiment at a temperature of 50 nK.? This was touted as the >coldest place in the universe.
--In year 2000 a Finnish lab cooled a rhodium metal chunk to 100 picoKelvin.. http://ltl.tkk.fi/wiki/LTL/World_record_in_low_temperatures (Was this really the coldest temperature in the universe? Perhaps there are natural refrigerators out there somewhere?) I am interested in the lowest temperature at which a physical system is known to undergo a phase transition. For example helium liquefying at 4.2K. Rhodium supposedly becomes superconductor at 325 microkelvins for example; that is much lower. I'd be interested in any lower-T candidates you can name (even speculative ones not yet demonstrated in lab). A Bose-Einstein condensate gas phase consisting of approximately 2000 rubidium-87 atoms was made via laser cooling and trapping below 170 nanoK effective temperature, but I don't know if we should admit that, since it really was a highly unnatural form of "matter."