Real one way glass

[liberonscien]

If I understand the physics correctly, there is no such thing as one way glass, i.e., glass that only allows light to pass through from one side. What could be done with such an anomalous kind of glass?
To clarify, this glass is also a perfect mirror because if this glass was to absorb energy from the other side then the glass would violate the one way rule.

[Flumble]

I'll start off with: reducing entropy and thereby violating the second law of thermodynamics.

[gmalivuk]

A sphere of the stuff that lets light in but not out would make a convenient solar battery or time bomb, depending on how quickly it released stored energy.

[quantropy]

If I understand the physics correctly, there is no such thing as one way glass?

Is this true though? After all in electronics you have diodes, and as far as I can see the same physics applies. It's true that diodes don't work at thermal energies, preventing the building of a Maxwell's demon device, but it seems to me that the corresponding argument would be that one-way glass wouldn't work if it were at the temperature of the sun.

[jewish_scientist]

A sphere of the stuff that lets light in but not out would make a convenient solar battery or time bomb, depending on how quickly it released stored energy.

Wait... if it lets in all photons regardless of their frequency or angle, then wouldn't this sphere be a black body?

[Thesh]

I would make a badass pair of sunglasses.

[gmalivuk]

In but not out, I said.

[Thesh]

In but not out, I said.

Like this?

https://en.wikipedia.org/wiki/File:Blac ... zation.png

[gmalivuk]

How's that supposed to prevent light from coming back out the hole it went in?

In any case, we'll need the OP to clarify exactly what's meant by one-way, as I was taking it to mean thermal radiation also doesn't pass back the other way (hence its being impossible).

[Zamfir]

How's that supposed to prevent light from coming back out the hole it went in?

Out-of-arrows-error.

[Thesh]

How's that supposed to prevent light from coming back out the hole it went in?

In any case, we'll need the OP to clarify exactly what's meant by one-way, as I was taking it to mean thermal radiation also doesn't pass back the other way (hence its being impossible).

It's just a visualization. Anyway, they said light does not pass through it in one direction; I assume that means the other direction they get absorbed, which means it could radiate that as heat. If it was also perfectly reflective, then that's another story - and another physical impossibility, I believe.

[Flumble]

In any case, we'll need the OP to clarify exactly what's meant by one-way, as I was taking it to mean thermal radiation also doesn't pass back the other way (hence its being impossible).

I'm going with this, too.

And also what's meant by "glass". If it's the regular optical stuff, we're bound to reversibility like in that one what-if.

[speising]

How's that supposed to prevent light from coming back out the hole it went in?

In any case, we'll need the OP to clarify exactly what's meant by one-way, as I was taking it to mean thermal radiation also doesn't pass back the other way (hence its being impossible).

When people talk about light, they typically mean visible light, not thermal radiation. Specifically in the context of one way mirrors.

[liberonscien]

How's that supposed to prevent light from coming back out the hole it went in?

In any case, we'll need the OP to clarify exactly what's meant by one-way, as I was taking it to mean thermal radiation also doesn't pass back the other way (hence its being impossible).

Energy can pass through it, but in one direction only.

[liberonscien]

How's that supposed to prevent light from coming back out the hole it went in?

In any case, we'll need the OP to clarify exactly what's meant by one-way, as I was taking it to mean thermal radiation also doesn't pass back the other way (hence its being impossible).

It's just a visualization. Anyway, they said light does not pass through it in one direction; I assume that means the other direction they get absorbed, which means it could radiate that as heat. If it was also perfectly reflective, then that's another story - and another physical impossibility, I believe.

One side allows light to pass through. The other is a perfect mirror.

[Thesh]

Hmm... But if you tried to make them into sunglasses, the reflection of your eye might appear to be superimposed on the image, and they just wouldn't be useful. I'm not sure there would be any legitimate use for that, then.

[gmalivuk]

...except for light bombs and solar batteries

[PeteP]

I think that does get around the whole "can't make something hotter than the source with passive optics" doesn't it? So fuck entropy!

[liberonscien]

...except for light bombs and solar batteries

Death rays?

[Thesh]

...except for light bombs and solar batteries

Well, I was aiming a little higher than you.

[liberonscien]

It occurred to me yesterday that such a piece of glass could be used to boost the signal range of an electronic device. What do the other users of this thread think?

[peregrine_crow]

Inverting gmalivuk suggestion, we could also use this to passively cool stuff. Make a sphere out of it with the reflective side on the outside and whatever is inside should reach absolute zero eventually (possibly after an infinite amount of time). Alternatively, you could make a heat shield out of it and have something survive flying through the sun.

[liberonscien]

Now what if one side is one way and the other side just absorbs the energy?

[LaserGuy]

Now what if one side is one way and the other side just absorbs the energy?

You can do this using an optical isolator.

[jewish_scientist]

If light enters the sphere and cannot leave via thermal radiation or some other means, then the result will be a kugelblitz given enough time.

[liberonscien]

If light enters the sphere and cannot leave via thermal radiation or some other means, then the result will be a kugelblitz given enough time.

Interesting. This kind of glass could, theoretically, be used to create a black hole? Interesting. This kind of glass could then be used to create doomsday devices besides capturing the sun's light and using it as a death ray.

[PeteP]

Well it would also have to be indestructible because otherwise the radiation pressure will tear it apart before that.

[liberonscien]

Well it would also have to be indestructible because otherwise the radiation pressure will tear it apart before that.

Well, it is a perfect reflector of all light.
I now realize that it would be somewhat difficult to work with. It would be difficult or impossible to cut with lasers.