Universal Mirror: Imagine the Exact Opposite of an Invisibility Cloak

Illustration for article titled Universal Mirror: Imagine the Exact Opposite of an Invisibility Cloak

No, the opposite of an invisibility cloak isn't a normal jacket, smartass. This universal mirror uses metamaterials to bounce light back at the same angle from which it came, so no matter where you stand, you can see yourself perfectly.


Normal mirrors reflect light back at a 90-degree angle, but this universal mirror reflects light, including microwaves and lasers, back in the exact same direction from which it originated. It uses metamaterials, structures smaller than the light's wavelength, to force said light to bounce back at this specific angle. Because metamaterials are so difficult to create, this universal mirror is only 1x10 centimeters in size, and can only reflect light with longer wavelengths (like microwaves).

Invisibility cloaks use these same metamaterials to guide light around an object instead of sending it back out, and while the opposite may not seem as cool, it may have just as many uses. It could be used for radar location, deflection laser weaponry and as a general-purpose shield. The tech is still a few years off, but it's very futuristic and interesting stuff. [MSNBC]


There is probably something more to this, but, it has been done for quite some time using mirrors (3 arranged as the corner of a cube) or a big-ass prim. The are usually called "retroreflectors" (see here: [en.wikipedia.org] ) and they basically let you see yourself -or your eyes- from wherever you look at it. There is one on the moon's surface used to bounce back a laser -with which the distance to the moon is monitored-. I once saw a big one (a replica to NASA's one) in a russian science museum and its mesmerizing. You see yourself 10 or 20 times, with your own eyes staring at you no matter how. Its quite spooky but amazingly cool.

Most "cat-eye" reflectors on bikes operate on the same principle, thing is they are just too small to see yourself reflected there.