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Old 13th October 2020, 11:18 AM   #81
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Originally Posted by theprestige View Post
I don't see a level trough of water in the scenario I'm looking at. Let's move on from the analogy back to the thing itself:

I have a bunch of molecules (atoms?) bouncing around. I hook up a device such that when a molecule hits it, it generates some electricity. The bouncing of the atoms is necessarily dampened by this process. How is the generation of electricity not possible in this scenario?
because the atoms would be bouncing against other atoms. they would all have the same energy. tiny atoms aren't bouncing against a bigger piece of equipment, they are bouncing against other atoms. Where does the work come from?
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Old 13th October 2020, 11:21 AM   #82
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Originally Posted by theprestige View Post
Where is the isothermal bath coming from? There's a sheet of graphene, connected to a switch of some kind. Molecules in the graphene impinge against the switch, triggering an electromechanical process (?).

What unstated assumptions do you need to state for my benefit, so that I understand the problem with this?
where is the energy coming from to keep the atoms 'bouncing around'?
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Old 13th October 2020, 11:22 AM   #83
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Originally Posted by theprestige View Post
What if I start with a piece of graphene that is hotter than its surroundings?

You seem to be trying to address the perpetual motion part of the claim, which I explicitly rejected and flatly don't care about. I'm only interested in the basic electromechanical part of the claim.

Say I heat up a piece of graphene and connect it to this switch. Will the Brownian motion generate electricity while the graphene cools off?
So what then is the point? we already have heat engines.
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Old 13th October 2020, 11:34 AM   #84
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Quote:
Additionally, they discovered that their design increased the amount
of power delivered. “We also found that the on-off, switch-like behavior
of the diodes actually amplifies the power delivered, rather than reducing
it, as previously thought,” said Thibado. “The rate of change in resistance
provided by the diodes adds an extra factor to the power.”
100% technobabble.

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Old 13th October 2020, 11:40 AM   #85
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Originally Posted by theprestige View Post
Fascinating. Tell me more. According to the second law, the motion of the molecules would slow as more of their energy was transformed into work. After a while the molecules would stop moving, and no more work could be extracted from them.
Entropy. Only works in a closed system.

Quote:
But my understanding is that Brownian motion is a perpetual motion arising from the nature of the molecule's existence as such. As long as they continue to exist, they will continue in their Brownian motion.
No. Brownian motion exchanges energy. This energy must have a source.

Quote:
So I think simply saying "Second Law of Thermodynamics" cannot be a rebuttal to the claim being made. A detailed understanding of molecular physics (and possibly quantum physics) is necessary to figure out what is going on here and what laws apply.
Such understanding is available.

Quote:
The key is probably in Feynman's reasoning for why Brownian motion can't do work. I doubt he simply appealed to the Second Law. If he had, there'd be no need to cite his opinion. You could just cite the Second Law.
Brownian motion exchanges energy. It does not create any. This is where the second law of thermodynamics comes in: Nothing creates energy. Full stop.

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Old 13th October 2020, 11:44 AM   #86
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Theprestige: perhaps there is some confusion about the law apparantly being violated here? In a typical perpetural motion machine (a while with magnets that move back and forth etc, say) it would often be conservation of energy that would be violated if it works as the inventor claims. Here no-one is claiming any problem with conservation of energy, but rather with non-decrease of *entropy*.

If you go back and read some of the explanations above bearning this in mind, maybe it will already be clear.

Perhaps you already understand this (sometimes you seem to be claiming to), but still want to know what's wrong with the details.

This is actually quite a tricky question, but in some sense also totally pointless. If an inventor claims that their strange wheel with moving parts inside always generates a turning force, and so can turn against a resistance, you presumably wouldn't want to go through their detailed calculations of the forces on all the bits at all times to find the error? You could, but you could also just say `there is clearly an error, because it violates energy conservation.'. If you did go through the details, and could find an error and persuade them of it, they would presumably just add a complication and claim that now it works.

The situation here is analogous (even with the added complication, I think, that being the second diode). The claim (as I currently understand it, and that also seems to be the consensus in the thread) clearly violates *entropy* non-decrease. Exactly what part of the calculation is wrong is probably rather tricky to figure out, but also pointless. And even the very simplified question as to why, tracing through all the forces etc, you can't get Brownian motion to do work is (as I understand it) quite tricky, with at least some cases answered in detail in a not very simple way.

A very simple analogy might be something like firing a cannon ball in a uniform gravitational field with no friction. When it lands, it's going the same spead as when it was launched. Why? Conservation of energy is the reason. You could say `Yes, but show me how it comes out of the equations of motion.'. Not so hard in that case (solve them to get the parabolic motion), but also not needed - it's perfectly valid to argue from the general principle instead. And the `micro' explanation is (I believe - I haven't even attempted to understand it myself) rather complicated in this Brownian motion case.
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Old 13th October 2020, 11:45 AM   #87
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Originally Posted by cjameshuff View Post
What you are interested in is totally irrelevant. You don't get to pick and choose when and where physical laws apply based on what is interesting.
I'm trying to understand how these physical laws apply to the claim in a way that makes it impossible for Brownian motion to transfer momentum from a hot sheet of graphene to a cooler electrical switch.

I'm not looking for you to tell me if it works or not. I hear you saying it doesn't work, loud and clear. I'm looking for an explanation of why it doesn't work.

I understand the conservation laws. I understand the water wheel analogy. I understand the need for an energy gradient of some kind. I understand that motion only lasts as long as the energy source for the motion.

What I don't understand is, if the graphene is hotter than its surroundings, why is it impossible to extract power from the motion of its constituent molecules?
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Old 13th October 2020, 11:49 AM   #88
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Originally Posted by theprestige View Post
I'm trying to understand how these physical laws apply to the claim in a way that makes it impossible for Brownian motion to transfer momentum from a hot sheet of graphene to a cooler electrical switch.

I'm not looking for you to tell me if it works or not. I hear you saying it doesn't work, loud and clear. I'm looking for an explanation of why it doesn't work.

I understand the conservation laws. I understand the water wheel analogy. I understand the need for an energy gradient of some kind. I understand that motion only lasts as long as the energy source for the motion.

What I don't understand is, if the graphene is hotter than its surroundings, why is it impossible to extract power from the motion of its constituent molecules?
The claim is that it can extract power with the graphene at the same temperature or at lower temperatures than the surroundings.
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Old 13th October 2020, 11:51 AM   #89
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Originally Posted by Meridian View Post
Theprestige: perhaps there is some confusion about the law apparantly being violated here? In a typical perpetural motion machine (a while with magnets that move back and forth etc, say) it would often be conservation of energy that would be violated if it works as the inventor claims. Here no-one is claiming any problem with conservation of energy, but rather with non-decrease of *entropy*.

If you go back and read some of the explanations above bearning this in mind, maybe it will already be clear.

Perhaps you already understand this (sometimes you seem to be claiming to), but still want to know what's wrong with the details.
No, I don't understand this part. Entropy is a somewhat opaque concept for me in this context (most contexts, really).

I understood the obection to be an objection to the conservation of energy violation. This is why I keep asking to set aside the energy source and just focus on the power generation mechanism itself.

It seems like what you're saying is that even if we use a nuclear reactor to keep the graphene heated for years at a time, we still wouldn't be able to generate electricity with the described method because of reasons having to do with the conservation of entropy. Is that what you're saying?
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Old 13th October 2020, 11:53 AM   #90
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Originally Posted by theprestige View Post
I'm trying to understand how these physical laws apply to the claim in a way that makes it impossible for Brownian motion to transfer momentum from a hot sheet of graphene to a cooler electrical switch.
It's not impossible. It is an exchange of energy. It does not create any, and it increases entropy.


Quote:
What I don't understand is, if the graphene is hotter than its surroundings, why is it impossible to extract power from the motion of its constituent molecules?
It is not, but no energy is created, just exchanged.

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Old 13th October 2020, 11:53 AM   #91
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Originally Posted by cjameshuff View Post
The claim is that it can extract power with the graphene at the same temperature or at lower temperatures than the surroundings.
Ok, thank you.

Does that mean that if the graphene was warmer than its surroundings, the system would in fact generate electricity?
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Old 13th October 2020, 11:54 AM   #92
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Originally Posted by theprestige View Post
What if I start with a piece of graphene that is hotter than its surroundings?

You seem to be trying to address the perpetual motion part of the claim, which I explicitly rejected and flatly don't care about. I'm only interested in the basic electromechanical part of the claim.

Say I heat up a piece of graphene and connect it to this switch. Will the Brownian motion generate electricity while the graphene cools off?

I have some lanterns that use the heat from a burning candle to generate LED light.

The efficiency of the overall conversion of the heat into visible light is about 5%.

However, the efficiency of a candle producing visible light is only about 1%. So the candle is giving off about 99 times more heat than light, which means the LEDs are about five times brighter than the candle by itself would be.

So yeah, we have lots of ways to turn heat into electrical energy or other forms of useful work. If you have a lot of heat at a high temperature you can put it near or inside a boiler and generate steam power. If you have a more moderate amount of heat at a lower temperature differential, you can vaporize a more volatile substance such as alcohol, and make other types of engines, or a little bird toy that bobs up and down for as long as one end of it stays wet (provided the room isn't too humid). If you have a small amount of heat at a high temperature, like my lantern's candle, you can use a thermoelectric generator (a lot of thermocouples). If you have individually very high-energy (hot) photons, but they're diffused over a large area, you can use a solar array.

If you heat up some graphene and connect it to the circuit illustrated, it will generate some electricity while the graphene cools off to ambient temperature. This will take a very small fraction of a second, and will generate a very small amount of electricity. The conversion will also be very inefficient, unless you arrange to heat the graphene to a very high temperature while keeping it intact. (Don't try this in air!)

But if you want to keep it running, you have to do something to continually heat the graphene. Such as, running an electric current through a resistance heater or burn some fuel or focus some sunlight on it. But the amount of electricity you'll get from the device is definitely less than the amount you need to run the resistance heater, and almost certainly less than you'd get by using the fuel to run a fuel cell, or using the fuel in a boiler or internal combustion engine to power a generator, or applying the sunlight to a conventional solar panel.

Small portable power sources don't have to be efficient to be useful. But they do have to perform at least as well as a small rechargeable battery, because those are already available at moderate prices. If the graphene device could do that, it wouldn't be touted as "unlimited" anything; it would be touted as "more efficient" or "more compact" or "cheaper to manufacture" or "more environmentally sustainable" or "more durable" than already-available technologies.
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Old 13th October 2020, 11:57 AM   #93
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Originally Posted by theprestige View Post
Ok, thank you.

Does that mean that if the graphene was warmer than its surroundings, the system would in fact generate electricity?
Who cares? Heat engines exist. Some of them are simple enough to be produced by accident, a junction of dissimilar metals is enough. It might function as one, but it doesn't have anything to do with their claims.
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Old 13th October 2020, 12:02 PM   #94
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Originally Posted by theprestige View Post
No, I don't understand this part. Entropy is a somewhat opaque concept for me in this context (most contexts, really).
Ah, ok. I think it's a slightly tricky concept, but the overall task of how to explain it is a very different one from trying to understand the fine details of this particular device.

Quote:
I understood the obection to be an objection to the conservation of energy violation. This is why I keep asking to set aside the energy source and just focus on the power generation mechanism itself.

It seems like what you're saying is that even if we use a nuclear reactor to keep the graphene heated for years at a time, we still wouldn't be able to generate electricity with the described method because of reasons having to do with the conservation of entropy. Is that what you're saying?
Yes, roughly speaking, depending on what you mean. In the paper they are quite explicit that the whole system is at one temperature. If they managed to generate electricty with the whole system at the same temperature (removing energy from the graphene as it's being replaced by some outside source at the same rate) that would violate non-decrease of entropy.

Basically, electrical energy has (approximately) zero entropy, and thermal energy has positive entropy, to an extent that depends on the temperature. At one temperature, you therefore can't convert thermal energy to electrical energy.

If your reactor heats the graphene to a high temperature, and some process transfers heat from it via some device to somewhere cooler, that can generate electricity as a side effect without violating the 2nd law. But there's a million ways to generate useable work from a temperature difference. (The key is that when you move some heat energy from a high temperature object to a lower temperature one, there is a net increase in entropy, because of the way entropy is a non-linear function of temperature.)

Last edited by Meridian; 13th October 2020 at 12:04 PM.
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Old 13th October 2020, 12:04 PM   #95
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Originally Posted by cjameshuff View Post
Who cares? Heat engines exist. Some of them are simple enough to be produced by accident, a junction of dissimilar metals is enough. It might function as one, but it doesn't have anything to do with their claims.
I care, obviously. At this point I'm just trying to make sure that at least some of my understanding is correct. I'm sure there are better heat engines than a hot scrap of graphite. What I'm trying to understand is if a hot piece of graphite can in fact be used as heat engine with a circuit such as they describe.

Never mind if their circuit also works (or not) on a cold piece of graphite.
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Old 13th October 2020, 12:07 PM   #96
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Originally Posted by theprestige View Post
I care, obviously. At this point I'm just trying to make sure that at least some of my understanding is correct. I'm sure there are better heat engines than a hot scrap of graphite. What I'm trying to understand is if a hot piece of graphite can in fact be used as heat engine with a circuit such as they describe.

Never mind if their circuit also works (or not) on a cold piece of graphite.
A circuit such as they describe, and their whole analysis, is about a system at one temperature.

The authors don't even raise the question of what would happen if their load resistor is at a lower temperature than the graphene.

You can raise it if you like, but it's not very interesting for the reasons others have said. Any electricity generation is going to be best understood in terms of a temperature difference, rather than the details of the brownian motion.
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Old 13th October 2020, 12:22 PM   #97
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Originally Posted by Meridian View Post
A circuit such as they describe, and their whole analysis, is about a system at one temperature.

The authors don't even raise the question of what would happen if their load resistor is at a lower temperature than the graphene.

You can raise it if you like, but it's not very interesting for the reasons others have said. Any electricity generation is going to be best understood in terms of a temperature difference, rather than the details of the brownian motion.
In fact, Brillouin's analysis of the original circuit was that if the resistor (the source of the Brownian current in the original setup) was at a lower temperature than the diode, the diode would develop a reverse voltage and drive a current through it. The circuit would operate as a heat engine with the diode as the hot side, which was verified by experiment.

The operation as a heat engine is uninteresting, it's not part of what they're trying to do. In fact, they're trying (in a ham-fisted way) to prevent it from operating that way. They're bent on using the graphene (in place of the original noise resistor) as a source of power, and so stuck another diode in reverse parallel (in ignorance of forward voltage maybe?). And the schematic seems to show a voltage source to bias the graphene so electrons tunnel between it and an electrode, which would of course bias the diodes as well. I'm not clear why they even have diodes with that voltage source in place, but suspect they're a result of the researchers modifying a circuit without understanding basic electronics.
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Old 13th October 2020, 12:30 PM   #98
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Thanks! I think that explains something in the paper that had been puzzling me: their claim that without the current the resistor would actually cool down.
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Old 13th October 2020, 12:41 PM   #99
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Originally Posted by theprestige View Post
I understood the obection to be an objection to the conservation of energy violation.
Not conservation of energy, conservation (or non-reduction) of entropy. We know there's energy in a uniform temperature system, it's just that we can't use that energy to do work. The idea that this graphene circuit can do so is the extraordinary claim.

Quote:
This is why I keep asking to set aside the energy source and just focus on the power generation mechanism itself.

It seems like what you're saying is that even if we use a nuclear reactor to keep the graphene heated for years at a time, we still wouldn't be able to generate electricity with the described method because of reasons having to do with the conservation of entropy. Is that what you're saying?
No, not really. We could use the nuclear reactor as a source of low-entropy (not "heat") and extract work (via many different mechanisms).

It is the claim that this circuit can extract work without such a source that is interesting and problematic. With a separate entropy sink, it is "just another" heat engine, of which we have many. Without the entropy sink, it becomes theoretically unworkable.

Without resorting to entropy, you could examine the brownian ratchet further. Given that you're in an environment with bouncing molecules, *how* would you extract energy from them? It turns out to be very difficult when you look at the details. Brownian_ratchetWP
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Old 15th October 2020, 10:15 AM   #100
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Originally Posted by BowlOfRed View Post
Not conservation of energy, conservation (or non-reduction) of entropy. We know there's energy in a uniform temperature system, it's just that we can't use that energy to do work. The idea that this graphene circuit can do so is the extraordinary claim.



No, not really. We could use the nuclear reactor as a source of low-entropy (not "heat") and extract work (via many different mechanisms).

It is the claim that this circuit can extract work without such a source that is interesting and problematic. With a separate entropy sink, it is "just another" heat engine, of which we have many. Without the entropy sink, it becomes theoretically unworkable.

Without resorting to entropy, you could examine the brownian ratchet further. Given that you're in an environment with bouncing molecules, *how* would you extract energy from them? It turns out to be very difficult when you look at the details. Brownian_ratchetWP
Interesting or not, what theprestige seems to be asking at this point is whether this circuit can indeed act as a heat engine given an appropriate source of heat.

The answer seems to be that it could. The catch that he didnít quite seem to understand at the start is that the heat source isnít just providing energy it is also acting as sink for the resulting entropy.
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Old 15th October 2020, 10:23 AM   #101
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Originally Posted by lomiller View Post
Interesting or not, what theprestige seems to be asking at this point is whether this circuit can indeed act as a heat engine given an appropriate source of heat.

The answer seems to be that it could. The catch that he didnít quite seem to understand at the start is that the heat source isnít just providing energy it is also acting as sink for the resulting entropy.
Yep! That's a pretty good nutshell of my misunderstanding.
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Old 15th October 2020, 10:47 AM   #102
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Originally Posted by theprestige View Post
No, I don't understand this part. Entropy is a somewhat opaque concept for me in this context (most contexts, really).

I understood the obection to be an objection to the conservation of energy violation. This is why I keep asking to set aside the energy source and just focus on the power generation mechanism itself.

It seems like what you're saying is that even if we use a nuclear reactor to keep the graphene heated for years at a time, we still wouldn't be able to generate electricity with the described method because of reasons having to do with the conservation of entropy. Is that what you're saying?
Their claim is the temperature is the same across the system. That'swhere it falls down.
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Old 15th October 2020, 10:57 AM   #103
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Work is Heat in Motion. Or, more explicitly, "Heat is the energy associated with the random motion of particles, while work is the energy of ordered motion in one direction". per https://energyeducation.ca/encyclopedia/Heat_vs_work
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Old 15th October 2020, 12:34 PM   #104
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Originally Posted by lomiller View Post
Interesting or not, what theprestige seems to be asking at this point is whether this circuit can indeed act as a heat engine given an appropriate source of heat.

The answer seems to be that it could. The catch that he didnít quite seem to understand at the start is that the heat source isnít just providing energy it is also acting as sink for the resulting entropy.
It might. The original resistor+diode circuit could function as a heat engine, they added a diode in reverse parallel in order to prevent it from operating that way.

But you can get a heat engine with two dissimilar metals joined together at one end with a temperature gradient along their lengths. Technically you could even consider a single piece of metal to be a heat engine, you just need a conductor with different properties to actually make use of the voltage developed by the Seebeck effect. So it's actually not easy to say for certain that something can't operate as a heat engine, and it doesn't mean much if it can.
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Old 15th October 2020, 03:01 PM   #105
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SGU guys will apparently have the lead author on the podcast this Saturday. My interpretation of the the Neurologica blog is that we have understood the claim properly (there is no external source of lower entropy), but supposedly if you use the New Thermodynamics (TM), this isn't a problem like Feynman thought it was.

Quote:
Previously physicists believed that such Brownian motion could not be used as a source of energy. You could not harvest energy from Brownian motion. [...]
The new field of stochastic thermodynamics was necessary to understand what is happening. With the math sorted, they were able to get the results published.
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Old 15th October 2020, 03:07 PM   #106
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'New Thermodynamics'

Making **** up?
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Old 15th October 2020, 04:03 PM   #107
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Originally Posted by Captain_Swoop View Post
'New Thermodynamics'

Making **** up?
I actually staggered off and read the wikipedia article Stochastic_thermodynamicsWP. Twice.

My best cut at understanding is that , "If thing are very small they may be different". There are disclaimers that anything scales up to a macroscopic level.

I'll wait for the Nobel Prize announcement.
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Old 16th October 2020, 11:37 AM   #108
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Originally Posted by Gord_in_Toronto View Post
I actually staggered off and read the wikipedia article Stochastic_thermodynamicsWP. Twice.

My best cut at understanding is that , "If thing are very small they may be different". There are disclaimers that anything scales up to a macroscopic level.

I'll wait for the Nobel Prize announcement.
I guess if all you need is "very small" amounts of power, then this could be . . . useful? No, that seems like the wrong word all around.
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Old 16th October 2020, 01:56 PM   #109
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Originally Posted by Dr. Keith View Post
I guess if all you need is "very small" amounts of power, then this could be . . . useful?
If it works (and isn't prohibitively expensive, and doesn't have horrible reliability, etc., etc.), then I'm sure it would be useful. There are lots of usecases for devices that need tiny amounts of power, but where external connections or batteries are problematic.
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Old 17th October 2020, 02:08 PM   #110
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Listened to the podcast, here's what I thought the big parts of the discussion were.

* Feynman didn't really study this. The lecture that folks refer to a lot about the Brownian ratchet was his interpretation of work by Brillouin.
* Brillouin was wrong about the diode being an impossible ratchet because he was making certain assumptions that turn out not to be correct. The non-linear nature of the diode (and the graphene circuit) was not fully interpretable by the mathematics of the time. A more complete interpretation is that these devices are not prohibited.
* The apparent reduction of entropy of this circuit was not explicitly mentioned or discussed.


As the math is well beyond my ability to understand, I didn't find that the discussion did much to lower my skepticism of the device. Mass production/commercial use would solve that problem though.
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Old 17th October 2020, 05:47 PM   #111
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If this device were to work as claimed, it would essentially be a perpetual motion machine of the second kind. In other words, it would not be defying the first law of thermodynamics and creating energy from nothing but rather defying or circumventing the second law and extracting usable energy from the ambient heat in the environment without requiring a second lower temperature heat reservoir.

The basic idea being explored here is actually not new to me, for it's one I had myself decades ago. Of my own ideas, however, I had decided this one would be one of the most difficult to pursue personally (if not also perhaps the least promising), so I'm kind of glad that someone is now looking into it.

Anyway, here's the link to the podcast BowlOfRed is speaking of:

https://www.theskepticsguide.org/podcasts/episode-797

The interview with Paul Thibado begins about 54:20 into it and runs about half an hour.

Last edited by Shepherd; 17th October 2020 at 06:02 PM.
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Old 18th October 2020, 04:09 PM   #112
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Originally Posted by Shepherd View Post
If this device were to work as claimed, it would essentially be a perpetual motion machine of the second kind. In other words, it would not be defying the first law of thermodynamics and creating energy from nothing but rather defying or circumventing the second law and extracting usable energy from the ambient heat in the environment without requiring a second lower temperature heat reservoir.

The basic idea being explored here is actually not new to me, for it's one I had myself decades ago. Of my own ideas, however, I had decided this one would be one of the most difficult to pursue personally (if not also perhaps the least promising), so I'm kind of glad that someone is now looking into it.

Anyway, here's the link to the podcast BowlOfRed is speaking of:

https://www.theskepticsguide.org/podcasts/episode-797

The interview with Paul Thibado begins about 54:20 into it and runs about half an hour.
I can't see how it would be defying or circumventing the second law of thermodymanics.

Presumably in a closed system this device would increase entropy.

Say this was in deep space in a vacuum and with the graphene at close to absolute zero temperature. You put in such-and-such amount of work to get the molecules jiggling as they would in room temperature then you would (I assume) be able to get, at most, the same amount of work from the current produced.
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Old 18th October 2020, 06:02 PM   #113
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Originally Posted by Robin View Post
I can't see how it would be defying or circumventing the second law of thermodymanics.

Presumably in a closed system this device would increase entropy.
It purports to generate electricity. Exporting the electricity from the otherwise closed system requires the closed system to become cooler to comply with the first law. Entropy decreases violating the second law.
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Old 18th October 2020, 06:35 PM   #114
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Originally Posted by Robin View Post
I can't see how it would be defying or circumventing the second law of thermodymanics.

Presumably in a closed system this device would increase entropy.

Say this was in deep space in a vacuum and with the graphene at close to absolute zero temperature. You put in such-and-such amount of work to get the molecules jiggling as they would in room temperature then you would (I assume) be able to get, at most, the same amount of work from the current produced.
In a closed system the device would decrease entropy, producing a heat difference out of nowhere and driving the system away from thermal equilibrium. It would cool the graphene toward 0 K even in deep space with its 2.7 K background, while performing work to heat the resistor above 2.7 K.
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Old 18th October 2020, 11:46 PM   #115
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Originally Posted by marting View Post
It purports to generate electricity. Exporting the electricity from the otherwise closed system requires the closed system to become cooler to comply with the first law. Entropy decreases violating the second law.
But, in the situation I described, does it purport to be able to produce more work than it would have taken to set the atoms in the graphene in motion?
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Old 19th October 2020, 12:28 AM   #116
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Originally Posted by cjameshuff View Post
In a closed system the device would decrease entropy, producing a heat difference out of nowhere and driving the system away from thermal equilibrium. It would cool the graphene toward 0 K even in deep space with its 2.7 K background, while performing work to heat the resistor above 2.7 K.
Entropy will have decreased if there are fewer microstates associated with its new state.

Certainly the cooled graphene will have fewer microstates associated with it than the room temperature graphene, but would this be true of the system as a whole?

I am doubting this. The system will have been set up in such a way as to allow the heat in the graphene to transfer to another part of the system (ie more work has been put in to do this to set up the system).

Could the system now be able to reset itself, with no outside intervention, transfer the heat back to the graphene, start again and keep this cycle going indefinitely? I can think of a couple of reasons why this would not happen.
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Old 19th October 2020, 06:30 AM   #117
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Originally Posted by Robin View Post
Entropy will have decreased if there are fewer microstates associated with its new state.

Certainly the cooled graphene will have fewer microstates associated with it than the room temperature graphene, but would this be true of the system as a whole?

I am doubting this.
Yes, it would be true of the system as a whole if the graphene lowered in temperature compared to the rest of the system. That is, in fact, what temperature actually measures: how entropy changes with energy. The common explanation that temperature measures thermal energy itself is a false oversimplification used to avoid having to explain entropy to students who aren't ready for it.

Entropy is maximized by definition when the temperatures are equal. If heat flows from lower temperature to higher temperature, then that automatically means that entropy decreased.
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Old 19th October 2020, 09:58 AM   #118
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Originally Posted by Shepherd View Post
If this device were to work as claimed, it would essentially be a perpetual motion
machine of the second kind.

Yes. I thought as much.

The flow of energy from the graphene reservoir into the resistor reservoir cools
the graphene and warms the resistor thus transferring heat from a cool reservoir
to a hot reservoir.

He said one watt per square meter.
A million layers and you have a cool cube that can power your Delorean.

Iím pretty sure the diodes do not work as amplifiers as the mathematical
predicts. Instead they rectify radio frequency emissions from outside sources
heating up both the graphene and the resistor.

Removing the radio noise from the picture will take effort ó a Faraday Cage,
maybe coated with radio adsorbing organics, and putting the whole thing in
a cave or mine.

Alternatively, they could hook up something guaranteed not to work in place
of the graphene, or just leave it out entirely, and see if the circuit still works.


P. S. I found a few photographs of the device.
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Old 19th October 2020, 10:11 AM   #119
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Originally Posted by Solitaire View Post
He said one watt per square meter. A million layers and you have a cool cube that can power your Delorean.
Is that one watt per square meter of device, or one watt per square meter of graphene? Because there's going to be a really big difference there.

Quote:
Iím pretty sure the diodes do not work as amplifiers as the mathematical predicts. Instead they rectify radio frequency emissions from outside sources heating up both the graphene and the resistor.
Wouldn't be surprised if it's something like this. But the power density can't be a watt per square meter of device in that case, RF noise isn't generally that powerful. And output wouldn't scale with stacking either.
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Old 19th October 2020, 10:53 AM   #120
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Originally Posted by Ziggurat View Post
Is that one watt per square meter of device, or one watt per square meter of graphene? Because there's going to be a really big difference there.



Wouldn't be surprised if it's something like this. But the power density can't be a watt per square meter of device in that case, RF noise isn't generally that powerful. And output wouldn't scale with stacking either.
Reminds me of a summer job at Analog Devices in Boston. There was this anomalous DC offset of a few hundred uVs showing up. Turned out to be rectification from an FM radio station across a transistor's emitter/base bias point.

Instrumentation error with these tiny units would be hard to recognize.

Let's see. There are two principal possibilities:

1. Either the First, Second, or Both Laws of Thermodynamics are wrong, or:
2. There are subtle instrument errors.

Human nature, being what it is ......
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