On Wednesday, March 19, 2014 11:31:28 PM UTC, Liz R wrote: > > Thank you. Here is a link to the article in question. Unfortunately I > don't wish to spend $32 on buying it in its entirety, but the abstract > gives the general idea. It looks as though the heat produced by erasing a > bit of information has been experimentally detected via what looks like > some delicate measurements. > > (Note - this doesn't indicate that any information is actually being > destroyed! The bit in question has been turned from the state of a molecule > into heat radiation or thermal motion, so unitarity isn't violated :-) > > http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html<http://www.nature.com/search/executeSearch?sp-advanced=true&sp-m=0&siteCode=default&sp-q=&sp-p=all&sp-q-2=Berut&sp-p-2=all&sp-q-3=&sp-p-3=all&sp-q-4=483&sp-q-5=&sp-q-6=187&sp-q-10=&sp-q-11=&sp-q-12=&sp-start-month=&sp-start-year=&sp-end-month=&sp-end-year=&sp-date-range=0&sp-q-8=&sp-s=&sp-c=25> > > Experimental verification of Landauer’s principle linking information and > thermodynamics > > - Antoine > Bérut<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#auth-1> > , > - Artak > Arakelyan<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#auth-2> > , > - Artyom > Petrosyan<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#auth-3> > , > - Sergio > Ciliberto<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#auth-4> > , > - Raoul > Dillenschneider<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#auth-5> > > - & Eric > Lutz<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#auth-6> > > > > - > Affiliations<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#affil-auth> > - > Contributions<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#contrib-auth> > > - Corresponding > author<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#corres-auth> > > Nature 483,187–189(08 March 2012)doi:10.1038/nature10872 Received 11 > October 2011 Accepted 17 January 2012 Published online 07 March 2012 > Article tools > > - > Citation<http://www.nature.com/nature/journal/v483/n7388/ris/nature10872.ris> > - > Reprints<https://s100.copyright.com/AppDispatchServlet?publisherName=NPGR&publication=Nature&title=Experimental+verification+of+Landauer%2F%26%23x27%3Bs+principle+linking+information+and+thermodynamics&contentID=10.1038%2Fnature10872&volumeNum=483&issueNum=7388&numPages=3&pageNumbers=pp187-189&orderBeanReset=true&publicationDate=2012-03-07&author=Antoine+B%26%23x000E9%3Brut%2C+Artak+Arakelyan%2C+Artyom+Petrosyan%2C+Sergio+Ciliberto%2C+Raoul+Dillenschneider%2C+Eric+Lutz> > > - Rights & > permissions<https://s100.copyright.com/AppDispatchServlet?publisherName=NPG&publication=Nature&title=Experimental+verification+of+Landauer%2F%26%23x27%3Bs+principle+linking+information+and+thermodynamics&contentID=10.1038%2Fnature10872&volumeNum=483&issueNum=7388&numPages=3&pageNumbers=pp187-189&publicationDate=2012-03-07&author=Antoine+B%26%23x000E9%3Brut%2C+Artak+Arakelyan%2C+Artyom+Petrosyan%2C+Sergio+Ciliberto%2C+Raoul+Dillenschneider%2C+Eric+Lutz> > > - Article > metrics<http://www.nature.com/nature/journal/v483/n7388/nature10872/metrics> > > In 1961, Rolf Landauer argued that the erasure of information is a > dissipative > process1<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#ref1>. > > A minimal quantity of heat, proportional to the thermal energy and called > the Landauer bound, is necessarily produced when a classical bit of > information is deleted. A direct consequence of this logically irreversible > transformation is that the entropy of the environment increases by a finite > amount. Despite its fundamental importance for information theory and > computer > science2<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#ref2>, > > 3<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#ref3>, > > 4<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#ref4>, > > 5<http://www.nature.com/nature/journal/v483/n7388/full/nature10872.html#ref5>, > > the erasure principle has not been verified experimentally so far, the main > obstacle being the difficulty of doing single-particle experiments in the > low-dissipation regime. Here we experimentally show the existence of the > Landauer bound in a generic model of a one-bit memory. Using a system of a > single colloidal particle trapped in a modulated double-well potential, we > establish that the mean dissipated heat saturates at the Landauer bound in > the limit of long erasure cycles. This result demonstrates the intimate > link between information theory and thermodynamics. It further highlights > the ultimate physical limit of irreversible computation. > > > > On 20 March 2014 12:09, L.W. Sterritt <[email protected] <javascript:> > > wrote: > >> Liz, >> Discussion of this issue: Berut et al, Experimental verification of >> Landauer’s principle linking information and thermodynamics, Nature >> *483,* 187-189 (2012). >> >> Lanny Sterritt >> >> On Mar 19, 2014, at 1:53 PM, LizR <[email protected] <javascript:>> wrote: >> >> On 20 March 2014 00:54, Edgar L. Owen <[email protected] <javascript:>>wrote: >> >>> Brent, >>> >>> If information is not being lost then the amount of information in the >>> universe is increasing at a tremendous rate as new events occur, and has >>> been since the beginning. So where is all that new information being >>> stored? How can ever increasing amounts of information be being stored in >>> the SAME amount of matter states? >>> >>> As far as I know, unitary evolution in QM implies that the information >> content of the universe remains constant. This is why entropy is emergent, >> for example, even though it appears on the macroscale to change the amount >> of order and disorder. Since the laws of physics are time agnostic at the >> fundamental level (bar the usual caveat involving CPT violation) this is to >> be expected. You couldn't play physical scenarios backwards even in theory >> if information was being created, and the evolution of the wave function >> wouldn't be unitary if it was being lost. Hence it stays constant.. >> >> I always thought information was a context of energy and vice verca. I'm probably going to keep on thinking that until until someone puts me out of my misery by pointing what is fundamentally - or even superficially - different.
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