"Invisibility Cloak" created, no kidding...

So we have known for a long time that the way to make an "invisibility cloak" was to get the rays of light to bend completely around an object. That way we see what is behind that object instead of the object itself. Your eye assumes that light rays travel in a straight line, so the light that comes in to your eye always appears to be coming straight at you. If you bend the light you can trick the eye into thinking things are in a different place than they are.

A really simple example of this is is when you have a straw in a glass of water and it looks like the bottom of the straw is larger and moved to the side. The light bends when it passes form the water to the air. Our eyes think it travels in a straight line so we see it as larger and it a different place than it really is.

Now we have know that this was the way to make an invisibility cloak for a long time, we just haven't been able to actually make that happen.

But now a team of scientists in Germany has done it. They created a structure of crystals that bends lights to hide a small bump of gold. The light rays bend completely around the gold bump, making it invisible. Pretty cool huh?

Read more about it:

Reuters: Scientists hide gold with 3D invisibility cloak

The Associated Press: Cloak of invisibility takes a step forward