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Discussion > Off-Topic > 2nd law of thermodynamics violated on (comparatively) large scales

2nd law of thermodynamics violated on (comparatively) large scales

Ben (September 2nd, 2002, 10:03 pm)

This has certain ramifications for the creation of nanotechnology, etc, so I thought I'd post it. Here's the article from Nature ( www.nature.com/nsu/020722/020722-2.html ):

Researchers have shown for the first time that, on the level of thousands of atoms and molecules, fleeting energy increases violate the second law of thermodynamics1. This is the tenet that some energy will always be lost when converting from one type to another.

The breach may mean there is a limit to miniaturization and to our understanding of the living world. It suggests that at scales of millionths of a millimetre - where machines may one day operate, and where cells already do - the mechanics of large systems cannot simply be scaled down.

In some ways thermodynamics is like gambling. The first law - that energy cannot be created - tells us 'you can't win'. The second says 'you can't even break even'.

In other words, there is nothing unusual about winning a single game of blackjack, but over many games the house always wins. If a player keeps playing, they must eventually lose. And in thermodynamics, you're not allowed to leave the casino - hence the robustness of the second law.

Denis J. Evans and colleagues have discovered, not how to beat the house, but what happens in the realm between a single coin toss and a weekend in Las Vegas. To do so they measured water molecules' influence the motion of tiny latex beads held between lasers.

They found that over periods of time less than two seconds, variations in the random thermal motion of water molecules occasionally gave individual beads a kick. This increased the beads' kinetic energy by a small but significant amount, in apparent violation of the second law.

The gain is short-lived, and so could never amount to a source of free energy or perpetual motion. But it is big enough to confirm what physicists have long suspected.

Law enforcement

The first and second laws of thermodynamics are considered so fundamental that the United States Patent and Trademark Office will not consider patent applications that claim to violate them - unless a working model is provided with the application.

But violation of the second law of thermodynamics by small ensembles of particles within larger systems is not a new idea. Evans's team predicted it formally a decade ago2. And in 1878, the physicist James Clerk Maxwell wrote in a book review for Nature:

The truth of the second law is ... a statistical, not a mathematical, truth, for it depends on the fact that the bodies we deal with consist of millions of molecules...

Hence the second law of thermodynamics is continually being violated, and that to a considerable extent,

in any sufficiently small group of

molecules belonging to a real body.

For larger systems over normal periods of time, however, the second law of thermodynamics is absolutely rock solid.

Ed Gerstner is the Editor of Nature's Physics and Materials Portals

2nd law of thermodynamics violated on (comparatively) large scales

cruise (September 3rd, 2002, 9:39 am)

Sweet. Hmmm....interesting.

I'm curious as to why the "gain is short lived"...otherwise you'd have yourself a nice power source for nanotech :P

Hm...

Semirrahge (September 4th, 2002, 12:19 pm)

Rather poorly written, I thought - I could not follow it very well.

Anyhow, I just discovered that the text is a link, so... I'll go read it again. :) But what I was going to say is that I recently read a book on nanotech. I'm sure you've heard of Eric Drexler (I think is his name), you might want to check out the book. It was not written by him, and though it was not a biography, it did revolve around him for much of the book. Unfortunately, I forget the name of it ATM.

I'll try and remember it next time I hit the Library.

On the text being a link

Ben (September 4th, 2002, 2:30 pm)

Not my fault. Cruise...? :)

Yep, it's his new system.

Hellkeepa (September 4th, 2002, 4:48 pm)

HELLo!

You got it right, Ben: It's Cruise's new system that's acting up. ;-

I said it was a safer an easier solution with the URL-tags. :-D

On the article: I'm a bit with Semirrahge on it being a bit difficult to understand, but then again it's probably because I'm not that used to read high-tech science reports in english... :-/

Interesting non-the-less, if it does imply what I think it does (and it seems so based upon Cruise's responce. ;-)

Happy fraggin'!

bah, so it's a little buggy...

cruise (September 4th, 2002, 10:21 pm)

So stake me :P

The basic thrust of the article is that the second law of thermodynamics is more a law of averages than a physical limit.

There can be small amounts of flunctuations in the energy of a closed system, but overall, energy will be lost.

That I did copy

Hellkeepa (September 5th, 2002, 11:43 am)

HELLo!

Hehe, I feel the need to edit the link above (to something like this: http://turn.to/hellkeepa). :-

However, back to the case at hand. ;-)

I did understand that much, the only parts that were a bit diffuse was all the scientific terminology used, or at least parts of it: The bulk of it was comprehendable, although a bit "heavy" some times.

Thanks for the concern though. :-)

Happy fraggin'!

Well, then...

Semirrahge (September 6th, 2002, 12:40 am)

If that is true, Cruise - then... Hm. Interesting.

So, every time something happens at any level, energy is constantly being lost? I guess this should have been apparent to me from the start.

A little clarification from TsfE's resident physicist =)

Narainsbrain (September 8th, 2002, 5:04 am)

"...every time something happens at any level, energy is constantly being lost..."

That isn't really the main thrust of the article, Semi. It's the thrust of the Second Law.

What the article is saying is that energy can be gained from random processes, in the short term, but if you keep trying to do so, on average, you will lose energy instead of gaining it.

Here's an analogy for you: Consider energy = money. In a casino, monay isn't created or destroyed, it merely exchanges hands. That's the First Law. The Second Law says that if you keep playing, the house will win. In thermodynamics, the 'house' is heat - which is essentially the energy contained in the random motion of molecules. But it is possible to win. People do sometimes win at slot machines, don't they? But the Second Law isn't violated, because if you kept playing the slots (Is that proper colloquial? I've never been to a casino, I'm just guessing [edit by Ben: yeah, that's the right term]), you would lose.

So finally, what is the article saying? It's saying the scientists saw some latex beads occasionally 'win' - which is to say, the beads gained energy from the thermal motion of surrounding molecules. They got money from the house. But for the process to be any good, it has to keep producing energy. You've got to keep winning money from the house. And you can't do that, which is why it's not really a good power source.

just to add a small point:

Ben (September 9th, 2002, 2:29 am)

The surprise wasn't that you could occaisionally win -- that had already been observed on very small levels (i.e. a few nanoseconds, and a single molecule) -- it was the scale on which the second law could be violated: in this case, the level of, say, a cell, or a nanomachine.

Hey, that's big

Narainsbrain (September 10th, 2002, 7:28 am)

The size of a cell or nanomolecule? Yikes. Tough for the nanotech guys =)

Also, it seems like biological systems are a heck of a lot more robust than we'd though, if they keep getting kicked around like that.

Well, maybe I overstated

Ben (September 10th, 2002, 11:36 pm)

The violations probably don't happen across the entire cell, but they could happen across a significant portion of it, maybe a third (not that I really know what I'm talking about about this). Yeah, though -- bio systems are really really amazingly robust, in general.

Discussion > Off-Topic > 2nd law of thermodynamics violated on (comparatively) large scales

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