Directional Materials Could Spawn True One-Way Mirrors and Soundproofing

Thought experiment: Take two black objects and place them on either side of a sheet of this stuff that reflects or transmits infrared light depending on direction. If both objects above a given temperature they will constantly be producing black body radiation (particularly in the infrared spectrum). Asume that there is a mechanism (normal mirrors or otherwise) that directs all of this radiation from one object to the other. Except there is a one way mirror in between. So one object absorbs receives the black body radiation from both itself and the other and will, over time, become warmer.

I thought the second law of thermodynamics said that was ilegal.
Anyone else see maxwells damon here?

Also: happy dance if it is actually possible. I would love to see entropy proven false.

More likely we have a system which reflects or absorbs, or transmits or absorbs, in which case the energy absorbed would be radiated disproportionately such that entropy is still preserved.

@ niropa

I wouldn't say that the law of increasing entropy is so much be invalidated with your thought experiment, or even that the radiating would be disproportional in order to preserve it... given that both of these black objects started out with the same about of thermal energy, as the one on the 'clear' side of the one way mirror was added to the other's on the reflecting side, the object receiving all the radiating heat would increase in temperature... and then decrease. As the object on the clear side loses it's thermal energy by passing it through to the other, the object on the reflective side would increase in temperature, peak and then decrease. This is entropy taking back over, increasing.

Now, if thermal energy were continually added to the system, obviously the outcome would be different. Even if the amount of thermal energy stayed a constant, the temperature of the object on the reflective side would increase and plateau, an apparent violation of the law of entropy. However, since there is energy continually added to the system, this law is violated.

I see what you're trying to say niropa; and on the surface the logic is sound. When you dig a little deeper, however, the one way mirror thought experiment merely serves to delay the inevitable.

so thier trying to make a sound diode and light diode?

o.o sounds fun. !!!! idea !!!! curtains made out of that stuff that blocks light coming in but allows you to see out side!

Not quite, entropy states that energy always flows to the least concentrated state. Any temperature change between the objects, regardless of what happend later, would be a violation of thermodynamics because for a brief time the energy would be flowing from a low concentration to a high concentration. The energy difference in the blocks would hit a plateau regardless of added energy.

So, I read through the actual paper and they are talking about thermal, optical and acoustic diodes, which conduct energy more easily in one direction than the other, but always from the high energy side to the low energy side.

My guess is that some journalist along the way read "Asymmetric Wave Propagation in Nonlinear Systems" and translated it to "one way mirror" in an attempt to make it comprehensible, but in doing so distorted the actual nature of the system.

Niropa, kudos for digging a bit deeper and looking at the original paper. That is a rare quality these days.

that's nice to make that. What are the exact elements or objects you needed to make it

So in spite of the hyperbole,
this stuff sucks?

@extremechiton,

This is used for one-way viewing. seeing outside means light comes inside. I think what you want is a window made from polarized glass. That way the light would come inside with lower intensity, but you could still see outside.

Could they use this to block radiation waves?

after niropa's comment, i dunno how well this would work, but imagine if you will, a sphere made of this 1 way mirror, that allows light to enter, but not leave, then u cover half in thermo voltaic cells (lining the orb so as to not disrupt teh reflective inner coating) and voala, a bal lthat will catch sunlight, adn abosrob the heat (so the ball doesnt explode from super heated gas) yes, no, maybe? lol

We're on the brink of so many advances in technology its impossible to conceive what will come in our lifetime. Don't comment on my spelling, i know it sucks, i jsut dont care ;)