<div dir="ltr">Hi all,<div><br></div><div>Since Joe asked, I will add my two cents. </div><div>Interpreting these interesting results will be confusing unless we untangle two different though linked conceptions of information: the intrinsic statistical entropy of the signal vs the relationship that constraint on that signal statistic has to extrinsic work imposed on it to achieve this constrained state. The former is often described as syntactic information and the latter roughly corresponds to semantic information (though I don't like to use these terms because of their contamination by linguistic assumptions). </div><div><br></div><div>The standard measure of information as it is relevant to the Maxwell's demon thought experiment, and which has been explored in the past by such luminaries as Szillard, Brillouin, Landauer, etc., is what is at stake in this study. I believe that this information-energy conversion reflects the relation between potential (micro)states of the system (signal, channel, medium) under consideration and a constrained variant state, such that this reduction in degrees of freedom is the basis for the decreased uncertainty obtained. Since the constrained informational state of a physical medium is one that is necessarily displaced from its ground state there is an implicit energetic potential. As Landauer (1991) pointed out "Information is physical." It's not just a mathematical abstraction.</div><div><br></div><div>Where this can be confusing is that more colloquial uses of the term also implicate its referential property, which is bracketed from consideration in the sort of physically-minded analyses like the ones alluded to here. If we consider this additional referential aspect and its role in the reported study we will need to bring into consideration all the additional computational and manipulative apparatus and the physical work involved to precisely assess the effect. As the commentary article by <span style="color:rgb(0,0,0);font-family:Arial,sans-serif;font-size:13px;line-height:18px">Van den Broeck points out, this effectively dwarfs the microenergetics that is the focus of the study. I like his comparison to the energy disparities of current fusion experiments. But of course the final referential step is interpretation of these results by experimenters, since the instruments are only transducing signals. So one shouldn't worry that somehow this suggests that meaning might be equivalent to energy.</span></div><div><span style="color:rgb(0,0,0);font-family:Arial,sans-serif;font-size:13px;line-height:18px"><br></span></div><div><span style="color:rgb(0,0,0);font-family:Arial,sans-serif;font-size:13px;line-height:18px">There are many other important considerations here that I have skipped over such as the submicroscopic nature of this effect. It is important to recognize the counterintuitive nature of such atomic scale effects, that for example have become increasingly important for understanding molecular processes within living cells. It is at this scale that we may find important applications of these findings.</span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Fri, Jan 15, 2016 at 1:23 AM, Xueshan Yan <span dir="ltr"><<a href="mailto:yxs@pku.edu.cn" target="_blank">yxs@pku.edu.cn</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><u></u>
<div lang="EN-CA" link="blue" bgcolor="#ffffff" vlink="purple">
<div dir="ltr" align="left"><font face="微软雅黑">Dear Colleague，</font></div>
<div> </div>
<div dir="ltr" align="left"><font face="微软雅黑">Right? Wrong? We had better have some
judgments criterions. If it is true that information can be converted to energy,
we can ask geneticist, human communication researcher etc. to give some
significant answer from their practical work, empty talk here is
endless.</font></div>
<div> </div>
<div dir="ltr" align="left"><font face="微软雅黑">We can have the conclusion that
information can be converted to matter from teleportation study, does anyone
accept it？</font></div>
<div> </div>
<div dir="ltr" align="left"><font face="微软雅黑">Best，</font></div>
<div> </div>
<div dir="ltr" align="left"><font face="微软雅黑">Xueshan</font></div><font face="微软雅黑"></font><br>
<div dir="ltr" lang="zh-cn" align="left">
<hr>
<font size="2" face="Tahoma"><b>From:</b> <a href="mailto:fis-bounces@listas.unizar.es" target="_blank">fis-bounces@listas.unizar.es</a>
[mailto:<a href="mailto:fis-bounces@listas.unizar.es" target="_blank">fis-bounces@listas.unizar.es</a>] <b>On Behalf Of </b>Joseph
Brenner<br><b>Sent:</b> Friday, January 15, 2016 3:51 PM<br><b>To:</b>
fis<br><b>Subject:</b> [Fis] Fw: Toyabe 2010 [ Information converted to energy ]
/ Van denBroeck 2010 Thermodynamics of Information: REQUEST TOTERRENCE
DEACON<br></font><br></div><div><div class="h5">
<div></div>
<div><font size="2" face="Arial">Dear Folks,</font></div>
<div><font size="2" face="Arial"></font> </div>
<div><font size="2" face="Arial">I do not wish to be negative, but I think this
example is contaminated by a homunculus. There are so much energy coming into
the system from various sources that the alleged result is not surprising. I
would be glad to be wrong but the decision should be up to someone like Terry
with far greater knowledge than I.</font></div>
<div><font size="2" face="Arial"></font> </div>
<div><font size="2" face="Arial">Thank you,</font></div>
<div><font size="2" face="Arial"></font> </div>
<div><font size="2" face="Arial">Joseph</font></div>
<div><font size="2" face="Arial"></font> </div>
<div><font size="2" face="Arial"></font> </div>
<div style="FONT:10pt arial">----- Original Message -----
<div style="BACKGROUND:#e4e4e4"><b>From:</b> <a title="Collierj@ukzn.ac.za" href="mailto:Collierj@ukzn.ac.za" target="_blank">John Collier</a>
</div>
<div><b>To:</b> <a title="fis@listas.unizar.es" href="mailto:fis@listas.unizar.es" target="_blank">fis</a> </div>
<div><b>Sent:</b> Friday, January 15, 2016 8:09 AM</div>
<div><b>Subject:</b> [Fis] Toyabe 2010 [ Information converted to energy ] / Van
den Broeck 2010 Thermodynamics of Information / Cartlidge 2010 Information
converted to energy</div></div>
<div><br></div>
<div>
<p class="MsoNormal"><span style="COLOR:#1f497d">Stan Salthe sent the item below
to Pedro and myself, but not to the list, as he had used up his posting
allotment. With the permission of both of them, who think that this is an
important issue, I am posting some brief comments I made back to Stan, as well
as Stan’s email content, in the hope that the issue will get more discussion
this time.(I posted a link to the 2010 article when it came out.) The
relevant material starts below the line, and Stan’s email forwarded from Malcolm
Dean is below that. It concerns the use of changed boundary conditions to move
things rather than energy differences, suggesting that information can be used
instead of energy to cause changes in a system (another way of looking at this
is that information can be a force in itself, not merely a constraint on other
actions). In particular, the final state has greater free energy than the
initial state (it is in end state potential energy of the manipulated particles
in an electric field), the energy arising from the manipulation of the boundary
conditions based on the particle location. The original authors described this
as </span><b>information-to-energy conversion.</b><span style="COLOR:#1f497d"><u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d"><u></u> <u></u></span></p>
<div style="TEXT-ALIGN:center" class="MsoNormal" align="center"><span style="COLOR:#1f497d">
<hr align="center" size="2" width="100%">
</span></div>
<p class="MsoNormal"><span style="COLOR:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d">I posted a different pointer to
this to fis some time ago, but the reaction from the list was almost nothing, or
skeptical, though the main objection was that we could understand what was going
on without using the information concept. My response to that was that not
using the word does not mean that the concept is not being used.
<u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d">Of course, if you think that
information is always meaningful to some interpreter (alternatively, always a
coding of something that has had meaning to some mind, or the like) then the
argument in the paper is a nonstarter. I would argue that this puts unnecessary
obstacles in the way of a unified approach to information, and that the issue of
the interpretation of information gets obscured by presupposing information is
carried only by meaningful communication. <u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d">John
Collier<u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d">Professor Emeritus and Senior
Research Associate<u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d">University of
KwaZulu-Natal<u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d"><a href="http://web.ncf.ca/collier" target="_blank">http://web.ncf.ca/collier</a><u></u><u></u></span></p>
<p class="MsoNormal"><span style="COLOR:#1f497d"><u></u> <u></u></span></p>
<p class="MsoNormal"><b><span style="FONT-FAMILY:'Tahoma','sans-serif';FONT-SIZE:10pt" lang="EN-US">From:</span></b><span style="FONT-FAMILY:'Tahoma','sans-serif';FONT-SIZE:10pt" lang="EN-US"> Stanley
N Salthe [<a href="mailto:ssalthe@binghamton.edu" target="_blank">mailto:ssalthe@binghamton.edu</a>]
<br><b>Sent:</b> Thursday, 14 January 2016 4:56 PM<br><b>To:</b> Pedro Marijuan;
John Collier<br><b>Subject:</b> Fwd: Toyabe 2010 [ Information converted to
energy ] / Van den Broeck 2010 Thermodynamics of Information / Cartlidge 2010
Information converted to energy<u></u><u></u></span></p>
<p class="MsoNormal"><span style="FONT-FAMILY:'Times New Roman','serif';FONT-SIZE:12pt"><u></u> <u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p style="MARGIN-BOTTOM:12pt" class="MsoNormal">---------- Forwarded message
----------<br>From: <b>Malcolm Dean</b> <<a href="mailto:malcolmdean@gmail.com" target="_blank">malcolmdean@gmail.com</a>><br>Date: Thu,
Jan 14, 2016 at 6:13 AM<br>Subject: Toyabe 2010 [ Information converted to
energy ] / Van den Broeck 2010 Thermodynamics of Information / Cartlidge 2010
Information converted to energy<br>To: <u></u><u></u></p>
<p class="MsoNormal"><a href="http://www.nature.com/nphys/journal/v6/n12/full/nphys1821.html" target="_blank">http://www.nature.com/nphys/journal/v6/n12/full/nphys1821.html</a><u></u><u></u></p>
<p class="MsoNormal"><u></u><u></u></p>
<p class="MsoNormal">Nature Physics 6, 988–992 (2010)
doi:10.1038/nphys1821<u></u><u></u></p>
<p class="MsoNormal"><b>Experimental demonstration of information-to-energy
conversion and validation of the generalized Jarzynski
equality</b><u></u><u></u></p>
<p class="MsoNormal">Shoichi Toyabe,<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Takahiro Sagawa,<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Masahito Ueda,<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">Eiro Muneyuki<u></u><u></u></p>
<p class="MsoNormal"> <u></u><u></u></p>
<p class="MsoNormal">& Masaki Sano<br><br>In 1929, Leó Szilárd invented a
feedback protocol1 in which a hypothetical intelligence—dubbed Maxwell’s
demon—pumps heat from an isothermal environment and transforms it into work.
After a long-lasting and intense controversy it was finally clarified that the
demon’s role does not contradict the second law of thermodynamics, implying that
we can, in principle, convert information to free energy2, 3, 4, 5, 6. An
experimental demonstration of this information-to-energy conversion, however,
has been elusive. Here we demonstrate that a non-equilibrium feedback
manipulation of a Brownian particle on the basis of information about its
location achieves a Szilárd-type information-to-energy conversion. Using
real-time feedback control, the particle is made to climb up a
spiral-staircase-like potential exerted by an electric field and gains free
energy larger than the amount of work done on it. This enables us to verify the
generalized Jarzynski equality7, and suggests a new fundamental principle of an
‘information-to-heat engine’ that converts information into energy by feedback
control.<br><br><br><a href="http://www.nature.com/nphys/journal/v6/n12/full/nphys1834.html" target="_blank">http://www.nature.com/nphys/journal/v6/n12/full/nphys1834.html</a><u></u><u></u></p>
<p class="MsoNormal"> [ <------- Please send this PDF if you have
access. -- M. ]<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u><u></u></p>
<p class="MsoNormal"><u></u><u></u></p>
<p class="MsoNormal">Nature Physics 6, 937–938 (2010)
doi:10.1038/nphys1834<u></u><u></u></p>
<p style="MARGIN-BOTTOM:12pt" class="MsoNormal"><b>Thermodynamics of information:
Bits for less or more for bits?</b><br>Christian Van den Broeck<u></u><u></u></p>
<p class="MsoNormal">Recent advances in the formulation of the second law of
thermodynamics have rekindled interest in the connections between statistical
mechanics and information processing. Now a 'Brownian computer' has approached
the theoretical limits set by the rejuvenated second law. Or has
it?<br><br><br><br><br><a href="http://physicsworld.com/cws/article/news/2010/nov/19/information-converted-to-energy" target="_blank">http://physicsworld.com/cws/article/news/2010/nov/19/information-converted-to-energy</a><br>Physics
World, 19<u></u><u></u></p>
<p class="MsoNormal"><u></u><u></u></p>
<p class="MsoNormal">November 2010<b><u></u><u></u></b></p>
<p class="MsoNormal"><b><u></u><u></u></b></p>
<p style="MARGIN-BOTTOM:12pt" class="MsoNormal"><b>Information converted to
energy</b><u></u><u></u></p>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">Physicists
in Japan have shown experimentally that a particle can be made to do work simply
by receiving information, rather than energy. They say that their demonstration,
which uses a feedback system to control the electric potential of tiny
polystyrene beads, does not violate the second law of thermodynamics and could
in future lead to new types of microscopic devices.<u></u><u></u></span></p>
<p class="MsoNormal"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">The
experiment, carried out by Shoichi Toyabe of Chuo University in Tokyo and
colleagues, is essentially the practical realization of a thought experiment
proposed by James Clerk Maxwell in 1871. Maxwell envisaged a gas initially at
uniform temperature contained in a box separated into two compartments, with a
tiny intelligent being, later called "Maxwell's demon", controlling a shutter
between the two compartments. By knowing the velocity of every molecule in the
box, the demon can in principle time the opening and closing of the shutter to
allow the build-up of faster molecules in one compartment and slower ones in the
other. In this way, the demon can decrease the entropy inside the box without
transferring energy directly to the particles, in apparent contradiction of the
second law of thermodynamics.</span><span style="FONT-FAMILY:'Times New Roman','serif';FONT-SIZE:12pt"><u></u><u></u></span></p>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">Among
the many responses to this conundrum was that of Leó Szilárd in 1929, who argued
that the demon must consume energy in the act of measuring the particle speeds
and that this consumption will lead to a net increase in the system's entropy.
In fact, Szilárd formulated an equivalence between energy and information,
calculating that <i>kT</i>ln2 (or about 0.69 <i>kT</i>) is both the
minimum amount of work needed to store one bit of binary information and the
maximum that is liberated when this bit is erased, where <i>k</i> is
Boltzmann's constant and <i>T</i> is the temperature of the storage
medium.<u></u><u></u></span></p>
<h3 style="LINE-HEIGHT:15pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:#6c6cb7;FONT-SIZE:12pt">Spiral
staircase<u></u><u></u></span></h3>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">Toyabe
and colleagues have observed this energy-information equivalence by varying an
electric field so that it represents a kind of spiral staircase. The difference
in electrical potential between successive steps on the staircase
is <i>kT</i>, meaning that a thermally fluctuating particle placed in the
field will occasionally jump up a step but more often than not it will take a
step downwards. What the researchers did was to intervene so that whenever the
particle does move upwards they place the equivalent of a barrier behind it,
preventing the particle from falling beyond this point. Repeating the process
allows it to gradually climb the staircase.<u></u><u></u></span></p>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">The
experiment consisted of a 0.3 µm-diameter particle made up of two
polystyrene beads that was pinned to a single point on the underside of the top
of a glass box containing an aqueous solution. The shape of an applied electric
field forced the particle to rotate in one direction or, in other words, to fall
down the potential-energy staircase. Buffered by the molecules in the solution,
however, the particle every so often rotated slightly in the opposite direction,
allowing it to take a step upwards.<u></u><u></u></span></p>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">By
tracking the particle's motion using a video camera and then using
image-analysis software to identify when the particle had rotated against the
field, the researchers were able to raise the metaphorical barrier behind it by
inverting the field's phase. In this way they could gradually raise the
potential of the particle even though they had not imparted any energy to it
directly.<u></u><u></u></span></p>
<h3 style="LINE-HEIGHT:15pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:#6c6cb7;FONT-SIZE:12pt">Quantifiable
breakthrough<u></u><u></u></span></h3>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">In
recent years other groups have shown that <b>collections of particles can be
rearranged so as to reduce their entropy without providing them with energy
directly. The breakthrough in the latest work is to have quantified the
conversion of information to energy. By measuring the particle's degree of
rotation against the field, Toyabe and colleagues found that they could convert
the equivalent of one bit information to 0.28 <i>kT</i>ln2 of energy or, in
other words, that they could exploit more than a quarter of the information's
energy content.</b><u></u><u></u></span></p>
<p class="MsoNormal"><span style="FONT-FAMILY:'Times New Roman','serif';FONT-SIZE:12pt"><u></u> <u></u></span></p>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">The
research is described in <cite><span style="FONT-FAMILY:'Arial','sans-serif'">Nature Physics</span></cite>, and in
an accompanying article Christian Van den Broeck of the University of Hasselt in
Belgium describes the result as "a direct verification of information-to-energy
conversion" but points out that the conversion factor is an idealized figure. As
he explains, it regards just the physics taking place on the microscopic scale
and ignores the far larger amount of energy consumed by the macroscopic devices,
among them the computers and human operators involved. He likens the energy gain
to that obtained in an experimental fusion facility, which is dwarfed by the
energy needed to run the experiment. "They are cheating a little bit," joked Van
den Broeck over the telephone. "This is not something you can put on the shelf
and sell at this point."<u></u><u></u></span></p>
<p style="LINE-HEIGHT:13.5pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">However,
Van den Broeck does believe that the work could lead to practical applications
within perhaps the next 30 or 40 years. He points out that as devices get ever
more miniature the energy content of the information used to control them
– <i>kT</i> at room temperature being equivalent to about
4 × 10<sup>–21</sup> J – will approach that required to operate
them. "Nobody thinks of using bits to boil water," he says, "but that would in
principle be possible at nanometre scales." And he speculates that molecular
processes occurring in nature might already be converting information to energy
in some way. "The message is that processes taking place on the nanoscale are
completely different from those we are familiar with, and that information is
part of that picture."<u></u><u></u></span></p>
<h3 style="LINE-HEIGHT:15pt;MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:11.5pt">About
the author<u></u><u></u></span></h3>
<p style="MARGIN:0cm 0cm 0pt"><span style="FONT-FAMILY:'Arial','sans-serif';COLOR:black;FONT-SIZE:10pt">Edwin
Cartlidge is a science writer based in Rome<u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal"><span>John
Collier<u></u><u></u></span></p>
<p class="MsoNormal"><span>Professor Emeritus
and Senior Research Associate<u></u><u></u></span></p>
<p class="MsoNormal"><span>University of
KwaZulu-Natal<u></u><u></u></span></p>
<p class="MsoNormal"><span><a href="http://web.ncf.ca/collier" target="_blank">http://web.ncf.ca/collier</a><u></u><u></u></span></p>
<p class="MsoNormal"><u></u> <u></u></p></div>
<p>
</p><hr>
<p></p>_______________________________________________<br>Fis mailing
list<br><a href="mailto:Fis@listas.unizar.es" target="_blank">Fis@listas.unizar.es</a><br><a href="http://listas.unizar.es/cgi-bin/mailman/listinfo/fis" target="_blank">http://listas.unizar.es/cgi-bin/mailman/listinfo/fis</a><br><p></p></div></div></div>
<br>_______________________________________________<br>
Fis mailing list<br>
<a href="mailto:Fis@listas.unizar.es">Fis@listas.unizar.es</a><br>
<a href="http://listas.unizar.es/cgi-bin/mailman/listinfo/fis" rel="noreferrer" target="_blank">http://listas.unizar.es/cgi-bin/mailman/listinfo/fis</a><br>
<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature">Professor Terrence W. Deacon<br>University of California, Berkeley</div>
</div>