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."
Don't know if you want to count this: "During the 1970s, David Lee, Douglas Osheroff and Robert Coleman Richardson discovered two phase transitions along the melting curve, which were soon realized to be the two superfluid phases of helium-3.[21][22] The transition to a superfluid occurs at 2.491 millikelvins (i.e., 0.002491 K) on the melting curve. They were awarded the 1996 Nobel Prize in Physics for their discovery." http://en.wikipedia.org/wiki/Helium-3 -----Original Message----- From: math-fun-bounces@mailman.xmission.com [mailto:math-fun-bounces@mailman.xmission.com] On Behalf Of Warren D Smith Sent: Tuesday, December 10, 2013 4:23 PM To: math-fun@mailman.xmission.com Subject: [EXTERNAL] [math-fun] coldest
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." _______________________________________________ math-fun mailing list math-fun@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/math-fun
In 1991 a Finnish group (Hakonen et al.) discovered spontaneous ordering among the nuclear spins in silver at 560 picokelvins. That may still be the record, for observed phase transitions in ordinary bulk matter. -Veit On Dec 11, 2013, at 9:17 AM, "Cordwell, William R" <wrcordw@sandia.gov> wrote:
Don't know if you want to count this:
"During the 1970s, David Lee, Douglas Osheroff and Robert Coleman Richardson discovered two phase transitions along the melting curve, which were soon realized to be the two superfluid phases of helium-3.[21][22] The transition to a superfluid occurs at 2.491 millikelvins (i.e., 0.002491 K) on the melting curve. They were awarded the 1996 Nobel Prize in Physics for their discovery."
participants (4)
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Cordwell, William R -
David Makin -
Veit Elser -
Warren D Smith