one more energy contraption

[bazaarboy]

answer my question:
" Feynman demonstrated that if the entire device is at the same temperature, the ratchet will not rotate continuously in one direction but will move randomly back and forth, and therefore will not produce any useful work. 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."


damn you pawl!

 

[bazaarboy]

It wont work unless you replicate the electron transport chain in cellular membranes to produce the ATP in the first place. Basically what your asking is to replicate 5 cytochrome molecules artificially and then create an artificial proton motive force to drive the ATPsynthase enzyme which converts ADP to ATP.

Goodluck with that bit

the ETC is rather complex, I only mentioned ATP because it is so well known, in reality a simpler system would have been better suited, though the overall concept seems flawed

 

[Judgeneo]

Ok thinking stage 1 done.


Basically I think in theory this is possible, but may be impossible to make.


As I understand the system, the idea is to make a pipe containing a cylindrical object, this would then rotate due to Brownian motion, but the rotation would be limited to one direction thanks to ratchets in the cylinder. This has the effect of converting the latent heat and kinetic energy in the environment into rotational kinetic energy, which can be collected by means I don't understand.

If this system is to work it has to be very small, nano-scale/micro-scale sounds about right, or the energies from Brownian motion won't be enough to generate the rotation.

Where I foresee problems is the method of preventing clockwise rotation. A single ratchet likely won't be enough, multiple will have to be made (I'm thinking three or more) which adds significantly to the complexity of construction.

Assuming you can manage this (should be possible in the lab at least) we must then go back to the method of propulsion. The irregular shape of the container will serve to create point vortices at the corner of each ratchet, with will 'attract' the sharp edges of the rotating object, this will quite simply stop the rotation. (source: research I conducted last year following up on https://docs.google.com/viewer?url=http://people.bath.ac.uk/kdk22/KDKlotsaPhDThes.pdf )

This is of course presuming that the fluid flow behaves the same at the small Reynolds numbers created by the small dimensions of the chamber.


I short, I don't think it would work. Shame really

 

[James J]

the ETC is rather complex, I only mentioned ATP because it is so well known, in reality a simpler system would have been better suited, though the overall concept seems flawed

Simple to understand, hard to replicate. The best system for it was already designed, by nature

Theres too many variables which would completely destroy the generation of ATP in an artificial environment to make it plausible to actually generate, use then regenerate it without a lot of user control.

 

[bazaarboy]

Ok thinking stage 1 done....
I short, I don't think it would work. Shame really

thanks for lending your grey matter
it seems far greater minds than mine have tried and failed with this idea

 

[Vonhelmet]

The thing is, even if you could get it to work, you'd still be buggered by thermodynamics. If you heat the fluid to induce the Brownian motion, you'll just lose the energy brouhaha inefficiencies in the transfer. And if you're just going to sit it in still water, then why bother? You'd be as well to built a similar machine several thousand times larger and call it hydroelectric or tidal power.

 

[D.P.]

hmm just found this:

http://en.wikipedia.org/wiki/Brownian_ratchet

I was just thinking that various ideas of converting brownian motion of particles into useful energy exist but most fall down because there is no net motion.

All these ideas are just stupid. Build a nuclear power station and be done. Or if you feel inclined to get energy for free, a solar power farm.

 

[mrk]

This could be used to recharge portable device batteries on the go, no?

WAIT, WAT?

 

[Meridian]

seen a few threads suggesting if various contraptions can "make free" energy.
now, I'm not going to insult you by suggesting that the laws of thermodynamics can be violated
however, most of the energy around us goes unused, so take a look below and tell me if you think this machine is possible:

This is a microscopic machine, say about 100 microns in size.
It is built from two basic components: one is a pipe-like structure (something like a microtubule http://en.wikipedia.org/wiki/Microtubule)
The other part is an axle inside the microtubule.

See a picture of this structure:

The red part has a lumen that is not exactly cylindrical, but rather notched.
This makes rotation of the blue part impossible in a clockwise direction, and only possible anticlockwise by a gentle compression of the red notched area.

Ok that's enough microanatomy!

Anticlockwise rotation of the blue part will generate energy, eg. by generating ATP molecules http://en.wikipedia.org/wiki/Adenosine_triphosphate

Exact details about how ATP is generated is not needed, but similar chemical reactions are know to exist in nature. The point is we are utilising energy from the compression of the red notched bit to make covalent bonds.

The blue bit is prevented from rotating clockwise to prevent the reverse chemical reaction.

Soooo - what force are we using to rotate the blue bit?

Well, it's a free and abundant force: brownian motion. See the image below:

Basically the blue and red bits are attached to larger structures which constantly jiggle about but due to the molecular ratchet mechanism the blue bit only moves in one direction, generating high energy bonds, for us to use later...

So, is this possible? What do you think?

Isn't this just a very complicated version of Maxwell's Demon?


M

 

[Vonhelmet]

Isn't this just a very complicated version of Maxwell's Demon?


M

Yes. The Wikipedia article describes it as a "Brownian Ratchet" (linked above), which was a thought experiment version of Maxwell's Demon, and which was comprehensively dismissed by Feynman.

 

[Cosimo]

Serious business, this science lark.

Especially when melons generate energy.

 

[bazaarboy]

Yes. The Wikipedia article describes it as a "Brownian Ratchet" (linked above), which was a thought experiment version of Maxwell's Demon, and which was comprehensively dismissed by Feynman.

thank you, very succinctly put, though initially you thought brownian motion was caused by 'adjacent' molecules shaking the particle

 

[Vonhelmet]

thank you, very succinctly put, though initially you thought brownian motion was caused by 'adjacent' molecules shaking the particle

Well, given that Brownian Motion is just the natural movement of the molecules of a fluid due to their temperature, I'm still right. The particles in your video are only being moved by those moving fluid particles.

 

[bazaarboy]

Well, given that Brownian Motion is just the natural movement of the molecules of a fluid due to their temperature, I'm still right. The particles in your video are only being moved by those moving fluid particles.

I'm not sure you're interpreting brownian motion correctly. the phenomenon occurs in all matter, but is only visible in small particles eg dust, in a fluid which allows movement. its the particles that move, not the fluid - now that I've read up on theorems that tried to take advantage of this force it's clear

 

[Vonhelmet]

I'm not sure you're interpreting brownian motion correctly. the phenomenon occurs in all matter, but is only visible in small particles eg dust, in a fluid which allows movement. its the particles that move, not the fluid - now that I've read up on theorems that tried to take advantage of this force it's clear

Sorry, but you're wrong. Well, either that or my degree level physics lectures were wrong, but I doubt it.

Go and read the article about Brownian Motion at Wikipedia.

 

[ChroniC]

Couldnt you just enlarge this to the mechanical scale and just stick it in the sea. I think thats what that guy haas already done.

 

[bazaarboy]

Sorry, but you're wrong. Well, either that or my degree level physics lectures were wrong, but I doubt it.

Go and read the article about Brownian Motion at Wikipedia.

not gonna come to blows over this, but your wrongness is too tempting to ignore

you haven't stated a specific counter argument, but I surmise that you believe that Brownian Motion results from adjacent molecules causing movement in a small particle, which itself does not move - correct?

In that case Brownian Motion would not be seen in particles suspended in vacuum. However experiments have demonstrated just that, take a look at J. Vac. Sci. Technol. A 10, 243 (1992); doi:10.1116/1.578143

 

[Vonhelmet]

not gonna come to blows over this, but your wrongness is too tempting to ignore

you haven't stated a specific counter argument, but I surmise that you believe that Brownian Motion results from adjacent molecules causing movement in a small particle, which itself does not move - correct?

Yep.

In that case Brownian Motion would not be seen in particles suspended in vacuum. However experiments have demonstrated just that, take a look at J. Vac. Sci. Technol. A 10, 243 (1992); doi:10.1116/1.578143

Summarise it for me, I'm not looking it up.

Also, if there's particles in there then it's not a vacuum, surely?

Besides, particle/anti-particle pairs come into existence in a vacuum, which could cause it. If nothing else, the particle can't move itself if it's in a vacuum as short of emitting something it has nothing to push against.

 

[bazaarboy]

Summarise it for me, I'm not looking it up.

not that hard - 10 seconds of googling shows:

A glass microbubble (diameter ∼15 μm, wall 0.65 μm) was levitated in high vacuum by an actively controlled electric field. While held vertically, the particle moved freely in the horizontal plane under the influence of a central restoring force. The Brownian motion of the particle was observed and quantified by successive measurements of the oscillation amplitude in a horizontal axis.

Also, if there's particles in there then it's not a vacuum, surely?

The only particles present are those exhibiting Brownian Motion, all on their lonesome, no nearby fluid molecules to help...

Besides, particle/anti-particle pairs come into existence in a vacuum, which could cause it.

nope, Brownian Motion is not the result of electrostatic forces...

 

[Vonhelmet]

not that hard - 10 seconds of googling shows:

The only particles present are those exhibiting Brownian Motion, all on their lonesome, no nearby fluid molecules to help...

Yeah, I looked it up in the end, as it goes. Unfortunately the abstract doesn't really explain what they were looking for or why or what they think they found.

nope, Brownian Motion is not the result of electrostatic forces...

Brownian motion is the result of the particles bumping around, so if there are particles/anti-particles popping in and out of existence, then from time to time they will bump into the glass bubble.