Editing Absolute zero (section)

==Relation with Bose–Einstein condensate==
{{Main|Bose–Einstein condensate}}

[[File:Bose Einstein condensate.png|left|thumb|Velocity-distribution data of a gas of [[rubidium]] atoms at a temperature within a few billionths of a degree above absolute zero. Left: just before the appearance of a Bose–Einstein condensate. Center: just after the appearance of the condensate. Right: after further evaporation, leaving a sample of nearly pure condensate.]]
A [[Bose–Einstein condensate]] (BEC) is a [[state of matter]] of a dilute gas of weakly interacting [[boson]]s confined in an external potential and cooled to temperatures very near absolute zero. Under such conditions, a large fraction of the bosons occupy the lowest [[quantum state]] of the external potential, at which point quantum effects become apparent on a [[macroscopic scale]].<ref>{{Cite journal |last=Donley |first=Elizabeth A. |last2=Claussen |first2=Neil R. |last3=Cornish |first3=Simon L. |last4=Roberts |first4=Jacob L. |last5=Cornell |first5=Eric A. |last6=Wieman |first6=Carl E. |year=2001 |title=Dynamics of collapsing and exploding Bose–Einstein condensates |journal=Nature |volume=412 |issue=6844 |pages=295–299 |arxiv=cond-mat/0105019 |bibcode=2001Natur.412..295D |doi=10.1038/35085500 |pmid=11460153 |s2cid=969048}}</ref>

This state of matter was first predicted by [[Satyendra Nath Bose]] and [[Albert Einstein]] in 1924–1925. Bose first sent a paper to Einstein on the [[quantum statistics]] of light quanta (now called [[photon]]s). Einstein was impressed, translated the paper from English to German and submitted it for Bose to the ''[[Zeitschrift für Physik]]'', which published it. Einstein then extended Bose's ideas to material particles (or matter) in two other papers.<ref>Clark, Ronald W. "Einstein: The Life and Times" (Avon Books, 1971) pp. 408–9 {{ISBN|0-380-01159-X}}</ref>

Seventy years later, in 1995, the first gaseous [[Bose–Einstein condensate|condensate]] was produced by [[Eric Allin Cornell|Eric Cornell]] and [[Carl Wieman]] at the [[University of Colorado at Boulder]] [[NIST]]-[[JILA]] lab, using a gas of [[rubidium]] atoms cooled to {{nowrap|170 [[nano-|nanokelvin]]}} ({{val|1.7|e=-7|u=K}}).<ref>{{Cite web |last=Levi |first=Barbara Goss |author-link=Barbara Goss Levi |year=2001 |title=Cornell, Ketterle, and Wieman Share Nobel Prize for Bose–Einstein Condensates |url=http://www.physicstoday.org/pt/vol-54/iss-12/p14.html |archive-url=https://web.archive.org/web/20071024134547/http://www.physicstoday.org/pt/vol-54/iss-12/p14.html |archive-date=24 October 2007 |access-date=26 January 2008 |website=Search & Discovery |publisher=Physics Today online}}</ref><ref>{{Cite web |title=New State of Matter Seen Near Absolute Zero |url=http://physics.nist.gov/News/Update/950724.html |url-status=dead |archive-url=https://web.archive.org/web/20100601175245/http://physics.nist.gov/News/Update/950724.html |archive-date=1 June 2010 |publisher=NIST}}</ref>

In 2003, researchers at the [[Massachusetts Institute of Technology]] (MIT) achieved a temperature of {{nowrap|450 ± 80 picokelvin}} ({{val|4.5|e=-10|u=K}}) in a BEC of sodium atoms.<ref>{{Cite journal |last=Leanhardt |first=A. E. |last2=Pasquini |first2=T. A. |last3=Saba |first3=M. |last4=Schirotzek |first4=A. |last5=Shin |first5=Y. |last6=Kielpinski |first6=D. |last7=Pritchard |first7=D. E. |last8=Ketterle |first8=W. |year=2003 |title=Cooling Bose–Einstein Condensates Below 500 Picokelvin |url=http://www.dsf.unica.it/~michele/michele/picokelvin.pdf |url-status=live |journal=Science |volume=301 |issue=5639 |pages=1513–1515 |bibcode=2003Sci...301.1513L |doi=10.1126/science.1088827 |pmid=12970559 |s2cid=30259606 |archive-url=https://ghostarchive.org/archive/20221009/http://www.dsf.unica.it/~michele/michele/picokelvin.pdf |archive-date=9 October 2022}}</ref> The associated [[black body]] (peak emittance) wavelength of 6.4 megameters is roughly the radius of Earth.

In 2021, University of Bremen physicists achieved a BEC with a temperature of only {{nowrap|38 picokelvin}}, the current coldest temperature record.<ref name=":0" />