# Homework Help: Is it possible to 'disappear into thin air'?

1. Aug 25, 2004

### Shyla

This isn't really homework, just a point of interest that my teacher couldn't answer:

Is it possible to 'disappear into thin air'?

And if so, is it possible without movement?

I can't find anything in reference to this, so even if you post things that I could look at would be helpful.

Thanks

Shy

2. Aug 25, 2004

### Crumbles

You could say Carbon Dioxide ice dissapears into thin air because it sublimes. (It goes from solid to gas, without going through the liquid phase). Although it doesn't turn to gas all at once.

3. Aug 25, 2004

### maverick280857

Welcome to PF, Shyla!

Well if you mean that for human beings (and not carbon dioxide ), one of the primary reasons why we can't become "transparent" is that we're opaque (ideally, transparent bodies have what's known as a "zero reflection coefficient")--to be transparent, we have to be like water (which isn't perfectly transparent by the way) or a jellyfish.

Cheers
Vivek

4. Aug 25, 2004

havent you seen predator. But we would need those handy dandy comuters they have.

5. Aug 25, 2004

### humanino

If you mean "disapear" like in "nothing left" it is certainly impossible. Now if you mean "become invisible" it is theoretically possible : you just have, somehow, to reproduce light incoming from the left to the right. Then apply spherical symmetrizer Seriously, I think the US army is working on that and they might be more advanced than just the prototype step :surprise: But then of course, we European think your army is trying to build everything we already secretly know how to do :tongue2:

6. Aug 25, 2004

### Crumbles

Actually mate, the Japanese have already got somewhere with http://www.ananova.com/news/story/sm_747591.html [Broken]! Although it doesn't look like what u'd call perfect, that was over a year ago now! They may have made improvements.

Also: http://edition.cnn.com/2003/TECH/02/07/japan.invisible.ap/ [Broken]

Last edited by a moderator: May 1, 2017
7. Aug 25, 2004

### Artorius

LOL!

I heard about a military "invisibility suit" from some source a little while ago. If you use small emitters, like sequins, which transmit light that is coming in directly opposite the other side of the body, you could blend in quite well, similar to the Predator effect. It certainly wouldn't be as nifty as Predator, but could dramatically improve concealment for intelligence/recon missions. The one problem I see with the setup, though, is that it can't ever get dirty. :tongue2: