Argonne researchers posit way to locally circumvent Second Law of Thermodynamics

The second law of thermodynamics isn't really a fundamental physical law, but rather a promise based on statistics that says "disorder will increase or stay constant in a closed physical system".

That said, it's entirely possible for entropy to spontaneously decrease in a closed system, the probability of this happening is just astronomically small for typical macroscopic systems.

Example:

If you have a system consisting of two compartments that are separated by a wall, where one of the compartments contains N particles. The system has low entropy because all the particles are on one side of it. Now, if you remove the barrier between the two compartments, particles will distribute evenly on both sides, increasing the entropy of the system. If we assume that the position of the particles is random, the probability of finding all of them on one side of the system is (1/2)^N, which quickly converges to zero for most macroscopic systems, which often contain > 10^23 particles.

Countdown to a sci-fi movie where this idea is only half understood and the "proof of concept" device opens a portal to hell, where we meet the real Maxwell's demon...

Now that I've typed this, I want to see it happen.

From the publication itself:

> Note that in the discussed example the reservoir acts as some quantum analogue of the classical Maxwell demon. Namely, having been prepared in a special state, the reservoir is able to decrease the entropy of the system without the energy exchange with it, and can be referred to as a ‘quantum Maxwell demon’ […] In what was discussed above, an electron interaction with the quantum spin does not induce any correlations between the electron and the spin and, therefore, no classical correlations are present. Hence an important distinction between how do quantum and classical Maxwell’s demons operate.

So, it sounds like the "refrigerator-at-a-distance" (and thus energy transmission, when combined with a heat engine) actually (1) is more of a battery, and (2) doesn't interact with classical systems.

Is my reading correct?

Could have sworn that one of the tricky things about that law was that while it may appear that you are decreasing entropy locally, you are just increasing it somewhere else, thus entropy still increased in aggregate.

> if a small theoretical being sat at the door between the hot and cold rooms and only let through particles traveling at a certain speed. This theoretical imp is called "Maxwell's demon."

Maxwell's demon is considered a slight of hand because it requires energy to perform its task. But if a passive energy-free equivalent can be found with a novel quantum substrate then any liquid could be separated into hot and cold pools. I am highly sceptical of such a claim. The difference in temperature between these hypothetical pools would likely be too small to create any useful energy.

See also:

https://en.wikipedia.org/wiki/Exergy

https://en.wikipedia.org/wiki/Thermoelectric_generator

> "Although the violation is only on the local scale, the implications are far-reaching," Vinokur said. "This provides us a platform for the practical realization of a quantum Maxwell's demon, which could make possible a local quantum perpetual motion machine."

> For example, he said, the principle could be designed into a "refrigerator" which could be cooled remotely — that is, the energy expended to cool it could take place anywhere.

Perhaps there's another definition, but as far as I'm aware, a PPM has net negative/zero energy input from anywhere, be it local or remote.

That said, apart from hyperbolic misapplication of terminology (not a PPM, no circumventing Second Law), this does sound like interesting research.

This article seems a little light on details, and the original paper (not behind a paywall!) is quite dense, but some of my favorite paper's on Maxwell's demon are:

http://www2.pitt.edu/~jdnorton/papers/ExorcistXIV/Exorcist1....

http://www2.pitt.edu/~jdnorton/papers/ExorcistXIV/Exorcist2....

...and to ease into things, an article by one of the authors:

"The Simplest Exorcism of Maxwell's Demon -- No Information Needed"

https://web.archive.org/web/20140309110028/http://www.pitt.e...

It seems as though the authors are confusing Boltzmann's H-theorem and its cousins expressed in more complicated formalisms with the Second law of thermodynamics. That's a very common misconception, often resulting in announces of apparently great discoveries, while the sober account would be more akin to "we derived a theorem where this special expression, similar to Boltzmann's H-function, does not behave as one would expect based on the H-theorem, which in turn is proven to be valid only for a simplified model of ideal gas in special condition." Not so interesting. Second law is an experimental law that concerns macroscopic systems. So far, this law was not shown to be violated based on any broadly accepted theory.

So this article does the Maxwell Demon some injustice. There is a key point about the demon that when he is 'sorting' the particles into two bulbs or rooms, that the gate he is working on is frictionless. In this way, you can can see that there is no energy entering the system, yet the entropy is decreasing. Now, this is where things get interesting to me (please correct me if I'm wrong here). What the demon is adding is information to the system. It decreases entropy. Natural selection is a sort of maxwell demon in it's selection process. I have a theory though that it all evens out. The more complex/evolved the organism, the more entropy the organisms generate themselves.

Someone smarter than me: why is this totally bullshit and will never work?

A quick read of the paper shows it's mostly focused on systems with discrete levels; IIRC there's already plenty of thermodynamic weirdness in those, like "negative temperature" states in the Ising model and so forth. They touch on a continuous system in the final section, but that also includes a system with a finite upper bound to its energy (phonons). Wonder if that's related to the potential for 2nd Law violations.

There is a free PDF on the nature site, but the paper is also available on arxiv (https://arxiv.org/abs/1407.4437), the first version on the arxiv dates back to 2014. It's strange, but I find the arxiv version much more readable in terms of typesetting than the polished version in nature. Also there are additional appendices in the arxiv version.

You lost me at "locally". Of course if you take a closed system A and make it a subsistem of some bigger closed system B you are going to be able to diminish entropy at A by increasing entropy even further at (B + !A).

My grandmother's freezer was doing this 50 years ago, and I am pretty sure the engineers who designed it did not think their work was fundamental research in any way or form.

This doesn't actually violate the law. This just goes on to prove it.

The reduce the entropy locally but in the process of doing so, increase it globally. It strictly follows the 2nd law of thermodynamics.

The best thing with local and short-term effects is that eventually someone finds the way to extend the space and time boundaries a bit, then a bit more and then we are talking about astronomical scale.

Can be a nice story plot for a sci-fi book, in which science finds the way to defer the rise of enthropy to some almost infinitely distant moment in future (that end of time, we've always being expecting) and move the boundaries of locality to the observable universe. What a world that would be.

By "locally" I think they mean something like "entropy will decrease within what looks like a closed system, and it might not be immediately obvious where else in the universe the corresponding increase in entropy is occurring".

So not actually "free energy", but perhaps it could be used to stage a convincing demo to potential investors.

I don't see what the big deal is. Let's try the ideal gas. For starters temperature ∝ Kinetic energy

We have two rooms. One were molecules all travel at speed A and other room molecules travel at speed B and we open a small window.

Eventually, over a long period of time the temerature in both rooms will settle at a temperature between that of B and of A.

Let's try to formule this mathematically. This is something like the mean value theorem in calculus that f'(C)(B-A) = f(B) - f(A) for some intermediate value C. And here are function f(C) is the equilibrium temperature.

In statistical mechanics we imagine we could count the number of particles -- 10^23 or 10^25 -- something very large. And some fraction M travel at speed A and N-M of them travel at speed B. And we count the probabilities of various mixtures occurring.

Feynman Lectures on Computation is a great book https://www.amazon.com/Feynman-Lectures-Computation-Richard-...

"The authors are planning to work closely with a team of experimentalists to design a proof-of-concept system, they said." - Pardon if I'm mistaken, but this seems like a fancy way of saying they have no evidence at all so far.

arxiv preprint of original paper here: https://arxiv.org/abs/1407.4437

I just knew it! Soon it won't be that local after all. ;)

Original article[1].

[1] http://www.nature.com/articles/srep32815

Is not the 2nd Law of Thermodynamics always circumvented on Earth? We absorb more energy in the form of light from the sun than we emit.

I wonder if we're going to read titles like "Global warming solved? We're going to send heat to Mars?".

Maxwell's demon is probably laughing his head off.

I recall having an idea at least a bit similar to this years ago when I was heavily studying evolutionary informatics.

Some particularly avant garde types in that field have posited that the universe rather than having two constituents -- matter and energy -- has three primary first-order constituents. The third is information. Information is not merely an epiphenomena of matter and energy but a primary "thing."

If that is the case then there should be an E=mc^2 type equation that relates matter to information and energy to information and all three should be interconvertible. It would then further follow that energy can be converted into information and vice versa in the same way that matter can.

I then imagined a Dyson swarm of solar power satellites that produce a data stream encoding the energy they collect. This stream can be subscribed to and decoded to reconstitute this energy remotely. To globally conserve energy there would have to be a two-way aspect to this -- I imagined the receiver of energy transmitting "challenges" to the swarm that are then "solved" to yield energy stored in the form of the solution. The receiver then receives these solutions and executes them to generate what in effect would look like local perpetual motion. (But in reality energy is still being conserved.) It would look like a cryptographic hashcash-style challenge-response system with proof of work, but the energy input of the POW function can be reversibly extracted elsewhere.

If such a thing were possible and sufficiently efficient and could function in the presence of high latency, this could power a starship among many other things. If it were latency-tolerant it might also be a way to store energy. Save your laptop's power to its hard drive.

It reminds me a little bit of the "telematter stream" propulsion system from Peter Watts' Blindsight.