That doesn't sound as impressive as a thin-air holographic projection.

greendestiny · on May 7, 2015

I suggest you stick with your current thin-air holographic solution if you have one :)

TazeTSchnitzel · on May 7, 2015

Well, this one literally does it with thin-air:

TheLoneWolfling · on May 7, 2015

That has minor issues. Such as ozone not being good for you. Ditto, lasers powerful enough to ionize air. Also, the noise created.

Still intriguing though!

TheLoneWolfling · on May 7, 2015

Theoretically?

Some gas / dye that emits light (or even just becomes opaque) above a certain level of incident radiation, and two scanning lasers.

But as usual, in theory != in practice. Trying to get something that's safe, won't dissipate too quickly, and isn't opaque...

Air itself would work, but there's this minor matter of "ozone, and lasers powerful enough to ionize air, isn't the best for you".

I wonder if one could stimulate condensation... Though then you'd probably get water on things.