I think I've found Maxwell's Demon, however the demon is quite large...

[Nabo00o]

Ah, I see what you are saying 

By connecting them in such and such a way, he could decide "and see" where the backround magnetic field would enter and maybe by feedback be amplified....

[Cap-Z-ro]

I'm not sure exactly what is going on...only that an amplification or an increase in energy is  involved.

Its still not clear to me yet...your thread just may be a bridge to a better understanding of what is going on here.

Regards...

[Nabo00o]

Okey I attached a picture which should show the concept really clear, I hope it just shows up and doesn't stay hidden as a link.

The pipes between the tanks should be heat pipes, which are extremely efficient and fast at transporting heat, even at low temperature potentials.

Naboo

[lumen]

I'm not sure how much energy could be converted using something like this, but I have seen this before except it was done a bit different. In a very old book I once read there was something called a heat amplifier and it was a large tank filled with water and a smaller tank inside it, with a smaller tank inside that and smaller inside that. Each one pulling the heat from the previous tank and getting hotter. Same principal but different concept.

[Nabo00o]

I think the power capability of the entire system depends on how large the density change in a given fluid is in response to a temperature change. If it is minor I would assume that only a small temperature gradient would appear. But if the fluid has a very fast density response to a temperature change, and especially in the region of normal temperate air, then very sharp gradients could probably be created, which would allow larger temperature amplifications for each tank to be made.

It may be that even common air has a much better density response than water (as most gases probably do), but it doesn't conduct heat nearly as good as a water.
So the ideal fluid for this system would probably be something which expands rapidly to heating, but is also at the same time good at conducting heat.

It might be that air, combined with heat sinks of large surfaces  would work better.
Also, it is probably not necessary to make the tanks have a large volume, the only thing that really affects the process is how high you make them, and how well shielded it is from the outside temperature.

Naboo