Entropy?

So does any one think Brownian motion could be used to decrease the amount of entropy in a closed system?

So does any one think Brownian motion could be used to decrease the amount of entropy in a closed system?

Maybe if you plug it into a Bambleweeny 57 sub-meson brain tied to an atomic vector plotter, you could.

Does anyone have anything constructive to add? I figured they could make an AC generator by having a magnet in a coil of wires. obviously it would have to be a small magnet but it seems if you had a lot of them and some diodes you could make energy from heat.

Does anyone have anything constructive to add? I figured they could make an AC generator by having a magnet in a coil of wires. obviously it would have to be a small magnet but it seems if you had a lot of them and some diodes you could make energy from heat.

Yes, you can make electrical energy from heat. Its called a turbine.  Two questions:
1. Where are you planing to get the heat from?
2. How do you want to utilize this energy (power small devices, or run a submarine)?

Quote from: optimisticcynic on October 18, 2009, 07:28:18 PM

Does anyone have anything constructive to add? I figured they could make an AC generator by having a magnet in a coil of wires. obviously it would have to be a small magnet but it seems if you had a lot of them and some diodes you could make energy from heat.

Yes, you can make electrical energy from heat. Its called a turbine.  Two questions:
1. Where are you planing to get the heat from?
2. How do you want to utilize this energy (power small devices, or run a submarine)?

No a turbine gets energy from differences in heat. I am talking about converting heat into energy not differences in heat.
So to answer 1. the heat that is present in the environment.
2. nano machines.

I think that you would benefit from a basic physical mechanics course, but I think I get what you are trying to say. I hope all of this isnt too arcane for you.
First, I think you are talking about turning heat into electricity.  Remember that energy is a very loose term.  So, could we turn this heat into electricity, yes, of course we can.  There are in fact semiconductor devices that do just that.  If you apply a current to them they heat up, and if you draw current out of them they cool down.  You see these used in medical devices and lab environments where there is a requirement to maintain a constant temperature in a system.
The big problem with how you are viewing this is the principle of conservation of energy.  Heat is just a measure of energy in a given system. If you were to remove this heat to make electricity, you would reduce the amount of energy in the system and the object would get colder.  You would need an outside source to replenish this heat, or you would rapidly run out of energy in the system.
Take the example of the turbine I mentioned earlier.  A turbine does not generate electricity from the difference in heat, as you said. Rather, a turbine is simply converting potential energy, in the form of heat, into mechanical force used to turn a generator. Turbines need not be diriven directly by heat either. Hydro-electric plants use turbines, as do some wind farms.
However, lets stay with a heat driven turbine. A nuclear reaction is a great source of heat energy. If this reaction occurs in a tank of water, the water will become super-heated and turn to steam.  This steam, which has now expanded in size and therefore pressure, can be used to do the mechanical work of turning the turbine. It looses some of its heat in the process, and is eventually condensed and returned to the tank where it is re-heated by the nuclear reaction. Conservation of energy has not been violated because the total energy of the system, including the electricity generated is still the same.
Doing something similar to power generation at this scale in the nano world becomes tricky.  First of all, you cant use magnets and coils for motors or power generation (which is just a motor in reverse), because transient inductance in the wire tend to eliminate any electro-motive force you hope to generate. As if that werent bad enough, even the small resistances of wires start to play a huge part, and we have yet to find any viable super-conducting material that operates at anything approaching room temperature.
Also, if you wanted to rectify the source voltage you would have a problem with the diodes.  The best diodes available have a voltage drop of .3V and an internal resistance of about 10k Ohms. Any AC that you dumped into them would be dissipated as heat, provided you could even overcome the voltage drop.
Its a great idea you have there, but I dont think investors will be lining up any time soon. But if you figure it out I will certainly be on board.

No a turbine gets energy from differences in heat. I am talking about converting heat into energy not differences in heat.
So to answer 1. the heat that is present in the environment.
2. nano machines.

Ask yourself this question: is what you are proposing some form of perpetual motion machine?  If yes, it's impossible, if no then it may be technically feasible.

Quote from: optimisticcynic on October 19, 2009, 07:00:43 AM

No a turbine gets energy from differences in heat. I am talking about converting heat into energy not differences in heat.
So to answer 1. the heat that is present in the environment.
2. nano machines.

Ask yourself this question: is what you are proposing some form of perpetual motion machine?  If yes, it's impossible, if no then it may be technically feasible.

Everything has a reason. if it is impossible I want to hear why it is impossible.
the second law of thermal dynamics does not hold up on extremely small scale. I was wondering if we could use it to decrease the level of entropy in a system.
second do you know anything about this.
First of all, you cant use magnets and coils for motors or power generation (which is just a motor in reverse), because transient inductance in the wire tend to eliminate any electro-motive force you hope to generate.

I don't really understand what you are saying (you are generally pretty terrible at explaining your ideas), but I think you are suggesting a variant of a thought experiment called Maxwell's demon.

There is a box of gas with an insulating wall dividing the box into two halves.  There is a tiny hole in the center of the divider, where a clever little nanodevice only allows fast molecules into the right half from the left half and slow molecules into the left half from the right half.  Over time, fast molecules accumulate in the right half and slow molecules in the left half.  The temperature of the right half increases and the temperature of the left half decreases, in apparent violation of the second law and generating all the free energy in the world.  However, in reality the second law will not be violated because the entropy produced by the nanomachine to segregate the particles exceeds the decrease entropy caused by the segregation of the gas.  Some detailed calculations have indeed shown this.

Similarly, I think your little nanobots exploiting transient fluctuations in entropy will have the same problem.

I don't really understand what you are saying (you are generally pretty terrible at explaining your ideas), but I think you are suggesting a variant of a thought experiment called Maxwell's demon.

There is a box of gas with an insulating wall dividing the box into two halves.  There is a tiny hole in the center of the divider, where a clever little nanodevice only allows fast molecules into the right half from the left half and slow molecules into the left half from the right half.  Over time, fast molecules accumulate in the right half and slow molecules in the left half.  The temperature of the right half increases and the temperature of the left half decreases, in apparent violation of the second law and generating all the free energy in the world.  However, in reality the second law will not be violated because the entropy produced by the nanomachine to segregate the particles exceeds the decrease entropy caused by the segregation of the gas.  Some detailed calculations have indeed shown this.

Similarly, I think your little nanobots exploiting transient fluctuations in entropy will have the same problem.

Brownian motion rough explanation
In 1827 the biologist Robert Brown noticed that if you looked at pollen grains in water through a microscope, the pollen jiggles about. He called this jiggling 'Brownian motion', but Brown couldn't work out what was causing it. The first of the three papers that Einstein published in 1905 finally came up with an explanation.

Everything around us is made up of atoms and molecules: the chair you're sitting on, the food you eat, the air you're breathing. The idea of atoms has been around since the time of the ancient Greeks, and a century before Einstein, the great chemist John Dalton had suggested that all chemicals were made of tiny invisible molecules, which in turn were made of even tinier atoms. The problem was that there was no proof of their existence, until Einstein looked into the problem of Brownian motion.

Einstein realised that the jiggling of the pollen grains seen in Brownian motion was due to molecules of water hitting the tiny pollen grains, like players kicking the ball in a game of football. The pollen grains were visible but the water molecules weren't, so it looked like the grains were bouncing around on their own.

Einstein also showed that it was possible to work out how many molecules were hitting a single pollen grain and how fast the water molecules were moving - all by looking at the pollen grains.

Importantly, Einstein's paper also made predictions about the properties of atoms that could be tested. The French physicist Jean Perrin used Einstein's predictions to work out the size of atoms and remove any remaining doubts about the existence of atoms.

My idea is to use Brownian motion to power to move a magnet in a coil of wire. EireEngineer pointed out a couple of problems but no problem that says it will not be possible in the future. I still need to look up what he said about
because transient inductance in the wire tend to eliminate any electro-motive force you hope to generate.
P.S. believe it or not I am much more understandable in person
here is a interesting article on decreasing entropy in a system
http://www.newscientist.com/article/dn2572-second-law-of-thermodynamics-broken.html

How will the random jiggling of a tiny magnet produce net power?  The current in the wire would just be noise.

How will the random jiggling of a tiny magnet produce net power?  The current in the wire would just be noise.

I figured that a couple diodes could work. although todays diodes aren't good enough I figure eventually they will be. Unless there is some law that says they can not get good enough.

There is a limit, because the diodes themselves are made of atoms, which would exhibit a fundamental random noise.

Quote from: Euclid on October 19, 2009, 06:49:39 PM

How will the random jiggling of a tiny magnet produce net power?  The current in the wire would just be noise.

I figured that a couple diodes could work. although todays diodes aren't good enough I figure eventually they will be. Unless there is some law that says they can not get good enough.

In order for the jiggling to produce anything menaingful it would have to maintain a constant frequency as well. And I am still wondering where you are planning to get this heat from?

There is a limit, because the diodes themselves are made of atoms, which would exhibit a fundamental random noise.

I understand that but this can work on things up to the size of a red blood cell and move it a good distance. Seems it could make changes above the random noise level.

Quote from: optimisticcynic on October 19, 2009, 06:51:51 PM

Quote from: Euclid on October 19, 2009, 06:49:39 PM

How will the random jiggling of a tiny magnet produce net power?  The current in the wire would just be noise.

I figured that a couple diodes could work. although todays diodes aren't good enough I figure eventually they will be. Unless there is some law that says they can not get good enough.

In order for the jiggling to produce anything menaingful it would have to maintain a constant frequency as well. And I am still wondering where you are planning to get this heat from?

Not trying to produce anything meaningful. I am aiming to reduce the total entropy in a system. to see if there is a way to stop the death of the universe caused by it all reaching thermal equilibrium. best way to do that is to turn heat into a different form of energy.

Hmm, I have no problem with entropy increasing until the universe "dies".

Hmm, I have no problem with entropy increasing until the universe "dies".

I would like to keep it going a little longer. I do believe there is something besides the body but I don't know if it needs the universe or not so I would like to keep it around.

Quote from: ﮎingulaЯiτy on October 19, 2009, 08:31:18 PM

Hmm, I have no problem with entropy increasing until the universe "dies".

I would like to keep it going a little longer. I do believe there is something besides the body but I don't know if it needs the universe or not so I would like to keep it around.

Well if there is something beyond the body, I'm not really concerned about it surviving the end of the universe. It's a long time already, and delaying the inevitable a little bit more to extend the existence of that small piece of me doesn't really concern me. I wouldn't mind not existing if I didn't exist.
As for your case, if it truly transcends the stacked reductionistic systems of "biology/biochemistry/chemistry/physics", I doubt the laws of universe would apply. And what energy could this spiritual self need? Should we be heating corpses in their graves? I can't imagine something beyond our reality needing material conditions.

That's actually something I've always taken issue with... the idea that something can transcend physical causality, and yet can still have a discernible physical influence. And before we completely corrupt another thread, this second paragraph was rhetorical.  

Quote from: ﮎingulaЯiτy on October 19, 2009, 08:31:18 PM

Hmm, I have no problem with entropy increasing until the universe "dies".

I would like to keep it going a little longer. I do believe there is something besides the body but I don't know if it needs the universe or not so I would like to keep it around.

I wouldnt worry about it too much. The universe will still be here long after humans arent.

Read this.

wouldn't it be able to keep producing power if you had the ratchet side in a vacuum? it would take energy to make it a vacuum but as long as the seals are good wouldn't it work?

Quote from: bridget on October 21, 2009, 11:14:46 PM

Read this.

wouldn't it be able to keep producing power if you had the ratchet side in a vacuum? it would take energy to make it a vacuum but as long as the seals are good wouldn't it work?

I think you missed the point. In order for it to work the ratchet would have to be so small itself that it would start exhibiting Brownian Motion itself, negating the mechanical force generated. It has nothing to do with drag forces.

Quote from: optimisticcynic on October 22, 2009, 09:12:28 AM

Quote from: bridget on October 21, 2009, 11:14:46 PM

Read this.

wouldn't it be able to keep producing power if you had the ratchet side in a vacuum? it would take energy to make it a vacuum but as long as the seals are good wouldn't it work?

I think you missed the point. In order for it to work the ratchet would have to be so small itself that it would start exhibiting Brownian Motion itself, negating the mechanical force generated. It has nothing to do with drag forces.

no there wouldn't be any Brownian motion in the ratchet area if it was a vacuum.

Still Not getting it.  A simple way to visualize how the machine might fail is to remember that a ratchet and pawl small enough to move in response to individual molecular collisions also would be small enough to undergo Brownian motion as well. The pawl therefore will intermittently fail, allowing the ratchet to slip backward.

Still Not getting it.  A simple way to visualize how the machine might fail is to remember that a ratchet and pawl small enough to move in response to individual molecular collisions also would be small enough to undergo Brownian motion as well. The pawl therefore will intermittently fail, allowing the ratchet to slip backward.

Isn't the Brownian motion due to the molecules of gas/liquid in the ratchet area? if you remove the gas the ratchet wont fail because there will not be any gas in that are to create Brownian motion.

No, its due to motion in the paddlewheel side.