Experiment finally proves 100-year-old thought experiment is possible (w/ Video)
June 15, 2010 by Lisa Zyga
This image from the video below shows the machine that uses bouncing beads to perform work, confirming a thought experiment from 1912. Credit: University of Twente.
(PhysOrg.com) -- By building a machine that uses 2,000 bouncing beads to spin a paddle and perform work, researchers from the University of Twente have finally realized a long-debated thought experiment.
A similar machine was first proposed in 1912 by the Polish physicist Marian Smoluchowski. In his thought experiment, he suggested that tiny moving particles could generate enough force to spin a windmill-type paddle. A locking mechanism such as a pawl could prevent backward motion, forcing the wheel to move in the forward direction only.
However, several years later, physicist Richard Feynman argued that, in reality, the bouncing beads would not be capable of doing meaningful work. Feynman showed that, since the entire system operates at the same temperature, a pawl would occasionally slip off the wheel. As a result, the system would generate zero net movement.
Now, physicist Devaraj van der Meer from the University of Twente and his colleagues have demonstrated that such a machine can in fact spin the paddles forward only, generating a positive net movement. The details of their study will be published in an upcoming issue of Physical Review Letters.
Looking somewhat like a high-speed lotto machine, the new system consists of a vigorously shaken platform that causes 2,000 small glass beads to bounce around. When the beads make contact with the vanes of a windmill-like device inside the machine, the vanes move, turning a rod, which rotates a sensor.
In this machine, 2,000 bouncing beads spin the vanes of a ratchet. Credit: University of Twente.
The key challenge was getting the vanes to move in the forward direction only, which the scientists achieved with - somewhat surprisingly - duct tape. With duct tape covering one side of each vane, the vanes spun in one direction only. Since the beads lost more energy when they hit the soft duct-taped side than the non-taped side of the vanes, the machine generated a positive net movement.
Van der Meer noted that the machine doesn’t come close to violating the second law of thermodynamics, since the system is extremely inefficient. Most of the beads’ energy is lost through heat and sound.
However, the system could still provide scientists with insight into classical mechanics. For instance, the system exhibits a property called back interaction, so that not only do the beads move the vanes, but the vanes also move the beads. After the vanes begin to turn in one direction, the researchers observed a new roiling pattern in the beads.
The physicists say this back interaction might also occur in tiny “molecular ratchets,” which include molecules in the body such as RNA polymerase and protein kinesin. At much smaller scales, these molecules move themselves through the body by ratcheting along tracks inside cells. The macroscopic system built here could help researchers better understand how molecular ratchets work by allowing the researchers to observe and manipulate the interactions on a large scale.
More information: via: Science News
© 2010 PhysOrg.com
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Jun 15, 2010
Rank: 4.1 / 5 (8)
Ahhh...duct tape. It's like violence.
If it doesn't work: use more.
Jun 15, 2010
Rank: 4 / 5 (4)
It is a test that basically says that you can get useful work out of a system wich is very close to maxium entropy. This is huge. It could spell the beginning of drawing power out of ambient air.
Certainly not a _lot_ of power but maybe enough to power basic sensors. Think about your phone recharging itself by simply sitting on your desk - without any solar panels or whatnot.
Jun 15, 2010
Rank: 4.5 / 5 (6)
I think that a common theory is that random chaotic movement can not do work. A team of sled dogs pulling equally in every direct results a sled going nowhere (no work, and all the energy or movement basically amounting to zero).
The majority of sled-dogs need to move in the basic same direct in order for the sled to move in a useful direct (work).
The experiment shows that if you tweak chaos, you can get work or directed-energy. This experiment also showed that the directed energy also effected the general mass of chaos so that it began to move in a more useful and less chaotic way.
I think that is what this is about.
Jun 15, 2010
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Is not thermocouple energy free energy that exists everywhere?
Also, Maxwells Demon experiment is years away from being proven correct!
Jun 15, 2010
Rank: 5 / 5 (2)
Jun 15, 2010
Rank: 5 / 5 (2)
No the power from a thermocouple comes from the temperature differential between the hot and the cold junction.
Jun 15, 2010
Rank: 5 / 5 (2)
Graphene duct tape :)
Jun 15, 2010
Rank: 5 / 5 (1)
Jun 15, 2010
Rank: 5 / 5 (2)
In the above experiment both sides of the vanes are, on average, in a therodynamically equivalent state.
Jun 15, 2010
Rank: 1 / 5 (3)
Jselin:
Why would thermocouple voltage not be considered free energy?
Jun 15, 2010
Rank: 2.5 / 5 (2)
Jun 15, 2010
Rank: 5 / 5 (3)
Because it requires an external energy source to maintain (or at least establish) the temperature gradient in the first place.
Jun 15, 2010
Rank: 5 / 5 (2)
Thats right... a TC harvests energy from a temperature differential. (Much like a windmill harvests energy from a pressure differential)
Don't forget, thermocouples have a cold junction you rarely if ever see (inside the equipment). Read up on the Seebeck effect for details.
Jun 15, 2010
Rank: 3.7 / 5 (3)
Jun 15, 2010
Rank: 1 / 5 (1)
Not saying it doesn't work, but either the article author or the physorg translation sounds unecessarily mysterious- at least to me.
Now all we need is a way to apply this to vacuum energy, and we should be home free.
Jun 15, 2010
Rank: 5 / 5 (3)
The only way to violate it would be if the glass beads, when rotating the "windmill" fueled the own vibration that made them jump in the air. This is CLEARLY NOT THE CASE.
Jun 15, 2010
Rank: 5 / 5 (1)
You truly live up to your hype. Bravo yet again my old friend, you never cease to amaze.
droom
Jun 15, 2010
Rank: 3.5 / 5 (2)
Jun 15, 2010
Rank: 2.8 / 5 (4)
There is no energy extraction from random chaotic motion happening in this experiment, as the here applied mechanism quite horribly fails to emulate unbiased random chaotic motion in the first place.
Although there is kinetic energy transfer happening, it is indeed only by the effect of gravity coupled with the asymetrical nature of the "chaos generator", that non-zero net directivity is achieved.
The results of this experiment are therefor about as phenomenal as gaining energy from harvesting rainfall water :-P
Jun 16, 2010
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I spoke with an electrical engineer about the mystery voltage and the engineer said it was created by thermocouple energy.
Jun 16, 2010
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Jun 16, 2010
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Anyway, it's evident, this device doesn't work as a Maxwell's demon.
Jun 16, 2010
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Found a link covering this.
http://home.fnal....00000000
If that gets broken try
http://home.fnal....per.html
and then click on the conclusion.
Ethelred
Jun 16, 2010
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Jun 16, 2010
Rank: 3.5 / 5 (2)
Jun 16, 2010
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Jun 16, 2010
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Jun 16, 2010
Rank: 1 / 5 (1)
http://www.scienc..._Feynman
Actually, the placing duck tape on the paddles makes the whole experiment "Feynman invariant".
Jun 16, 2010
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By touching probes to the leads you create cold junctions. Magnetic fields are known to change Seebeck coefficients. I'm gonna go out on a limb here and say the temperature of your magnet is not exactly the same as your meter connections. The presence of voltage tells you so!
Jun 16, 2010
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Given that the shaken beads in Devaraj van der Meer's machines behave collectively like a fluid heated at the bottom and cooled at the top, so that the system demonstrated here can not be said to operate at a single temperature, nor be analogous to a system that is operated at a single temperature, I question its relevance to the Feynman-Smoluchowski ratchet.
Jun 16, 2010
Rank: 3 / 5 (2)
It makes sense what you said about the mystery voltage.
Ethelred:
There was an article in Physorg.com that talked about the Maxwell Demon thought experiment and how it could be correct without violating the 2nd Law of Thermodynamics. The article was titled: Could Maxwell's Demon Exist in Nanoscale Systems?
June 24, 2009 by Lisa Zyga. I believe the concept was based on quantum fluctuations in the nanoscale.
After thinking about all of these free energy perpetual motion machines I think one will find that another energy source of some sort will be needed to fuel the machine thereby negating the thought experiments.
However, after saying that I believe our universe is no less than a free lunch, which means there is a such thing as a free lunch!!!
Jun 17, 2010
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Jun 17, 2010
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No, this is not the model of the original thought experiment and no, it does not prove that Feynman was wrong.
The whole point of the original thought experiment is extraction of work from *gas* at thermal equilibrium! The model described in the article has absolutely no bearing on that problem as it extracts work from glass beads which everyone knows is possible. Their work will be relevant and newsworthy once they show a nanoscale version of their contraption true to the original thought experiment, but don't hold your breath as it would violate the 2nd law of thermodynamics (unlike the current version).
Here is a wikipedia article about the original thought experiment:
http://en.wikiped..._ratchet
Jun 17, 2010
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Jun 17, 2010
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Jun 17, 2010
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Jun 17, 2010
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Hopefully it'll sounds better than the current rice rockets on the road :)
Jun 19, 2010
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Jun 19, 2010
Rank: 1 / 5 (1)
No, you have to invest into source of vibrations first. The above device works only because there is energy density gradient.
Jun 19, 2010
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But the gradient is not one that has an angular moment - so the gradient in the experiment is irrelevant. It would also work without a gradient as long as the number of paticles is small.
Yes. The idea is that brownian motion does result - on occasion - in local gradients just by sheer random chance. The device turns because it reacts to such gradients in one direction but not in the other (by the pawl mechanism).
It is not a perpetuum mobile because an outside energy source is required - but it need not be an energy source that creates a gradient (e.g. a uniform source of heat could be enough to keep such a device on the nanoscale going)
Jun 19, 2010
Rank: 5 / 5 (1)
Absolutely right. Exacty. It's a nice visual, but really amounts to extracting energy from gravity. There is no true random motion. There is always the added bias of gravity. Each bead takes a curved path, all the paths bias downward. The paddle takes advantage of gravity's downward bias.
Try in zero gravity = fail.
Jun 20, 2010
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The problem being to get the chaotic force to operate in a controlled and directional manner (something of an oxymoron to express.) The duct tape absorbs some of the contrary motion and so the wheel overcomes the natural, entropic friction and wheel turns. VOILA!
The beads are just a means of supplying this chaos - not seriously intended as a permanent source, of course, there are serious outside energy additions, but they are not salient to the experiment.
Jun 21, 2010
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Jun 21, 2010
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That doesn't work because the number of particles hitting both sides is, on average, the same. Also the gradients that come into existence momentarily through random fluctuations are too small to overcome the friction of the system.
HOWEVER, if you go to the nanoscale then the number of particles become small and the RELATIVE gradients can become very large. Here such a system can work if it can capitalize on the random gradients fast enough.
Jun 21, 2010
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Jun 21, 2010
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Even so: the orientation in the experiment is perpendicular to any coriolis force so _even if_ the balls were deflected this would have no impact on the direction of rotation.