Aargh!
Rant ahead!
Hot button topic! Hot button topic! Hot button topic!
Invisibility is far, far more difficult than ANY movie or TV show wants to admit. Here are the problems:
Think about what invisibility means. You look at a person or object, and you see what is behind them as it they were not there. It has to work from every angle. No matter what direction someone looks at you, they have to see whatever is behind you along their line of sight.
And to be effective, the image that the person sees cannot be distorted by the presence of you in your invisibility suit.
And finally, when you move, there must not be a sign of image distortion that would give away your presence.
1. Invisible due to not emitting light at visible wavelengths:
• Won’t work. No visible emission => Black. If you had a suit that did this, your invisibility suit would be pitch black.
2. Invisible due to bending light around:
• This could theoretically work, but would be impossible in practice. It’s hard enough to get light to bend around an object, but think about the problems of getting the light waves straightened out again. Remember, it has to work from every angle. There can be no distortions and it has to handle when you move.
3. Invisible due to passing light through:
• How do you make your body transparent?
• Even if you achieve perfect transparency, there is still another problem. Edge effects and Distortion. Remember, a glass is transparent. What you see when you look through very clear and clean glass is the bending and surface interactions of the light. You have to have no distortion. That is *very*difficult problem and can only be solved by making your body and everything inside the invisibility field to have the same refractive index as your medium. (Air, water, whatever.)
Invisibility is fun, but we *might* get real invisibility suite/cloaks just after we get functional transporters. (And please don’t get me started on the so-called quantum entanglement effect that has gotten some press as transportation. (It depresses me that any person with scientific training would compare what has been achieved with Star Trek type transporters. Quantum entanglement is not transportation!
)
Sorry. I love sci-fi but as is often the case, some things are so hard to do that they are effectively impossible.
Beam me up, Scotty.
Bob