Can you super heat air with a laser and create a floating mirror?

Well the refractive index of this super heated air probably won’t be high enough to see around a corner, but yes, it will bend light rays slightly. It would be much, much easier and less expensive to just use a mirror…..

Like a mirage?

It would probably melt the mirror.

The illusion of water over a hot road’s surface is actually produced by heated air, not the asphalt. The shimmering effect we see is due to rising heat waves from the hot blacktop disturbing the heated air above the road. So I would think a laser played back and forth along an imaginary plane in the air would do something similar.

@ETpro Exactly. I was out with my telescope tonight looking at Mars, and I saw shimmering from heat lines. (Still saw a polar ice cap though!)

Actually the shimmering effect is due to turbulence in the air and differing refractive indexes of the hotter and cooler air.

I was imagining a convergence of several lasers in a grid or plane as well, but the refraction possible is severely limited by how much you can increase the temperature and how long the heat will stay in one place. Air does have a tendency to convect…. You might get 10 degrees out of a device like this. Don’t expect to see around a 90 degree corner.

@Shuttle128 maybe we could use it to spy into caves in afghanistan, or what not.

@Shuttle128 Well, yes. That’s what “heat lines” are—they’re just different refractive indexes of different temperatures of air.

because of air circulation, it wouldn’t be workable.

To the best of my knowledge, super-heated air doesn’t become reflective. The image you see reflected on the street is reflected off the road surface because you’re seeing the surface at such a shallow angle. And even if air did become reflective, you’d need to create a “glassy smooth” transition between the two air masses, which would be neigh impossible. And air heated to such extremes would most likely be above the combustion temperature of most solid objects near by, and would cause everything aroudn it to burst into flames.

@HungryGuy Think that through for a minute. The image you see reflected off the street surface, or a desert’s sands, only appears when a very hot sun is baking down on that surface. At any other time, even a very sunny winter day, ni mirage. It isn’t the heated air per se—you are right about that. It is the variance in refractive index in the boundary layer between the hot air above the road and the relatively cooler air higher up that bends, or reflects the light. You can read up on the cause here.

The thing is the light doesn’t actually reflect in a mirage it refracts….so technically @HungryGuy‘s right. In that it doesn’t become reflective. Light doesn’t actually reflect off the surface of the road, it refracts through the hot air just above the surface. The same could be done with heated air anyway, it’s just really hard to control where the hot air goes. Not to mention you’d need pretty shallow angles for it to do anything at all. Maybe if you had several heated panes in a curve shape that progressively bent the light rays around the corner.

I thought it would be something good for astronomers, since I know they compile information already from gravity fields and other patterns that are caused by celestial bodies and the astrophysics that go on. Maybe we could use this information to look around in space by finding celestial mirrors that might cook up randomly. This might take some seriously good luck. Much worse than looking for a needle in a haystack I would think.

Gravitational lensing would be far easier to accomplish than that though. All you gotta do is find a very massive object…..and there’s plenty in space.