Invisibility Cloaks: From Science Fiction to Reality

   The idea of invisibility cloaks is no longer a stretch of the human imagination, rather it has become another mere problem for man to solve. If we can.
   According to Alasdair Wilkins, a reporter for io9.com, there is, in theory, an "invisibility cloak that works in both space and time, shielding whole events from history itself."
   The latest development in 'invisibility technology' if you will, is what nationalgeographic.com calls a Space-Time Invisibility Cloak. "According to new research by British physicists, it's theoretically possible to create a material that can hide an entire bank heist from human eyes and surveillance cameras" (nationalgeographic.com).
   Excuse me!? Yes, you heard that right. Not only would the person committing the robbery be invisible, but both the robber and the entire criminal event would almost completely be erased from time and history itself. Almost.
   To realize the 'almost' part of the equation one must first understand how this cloak aims to render its preached invisibility.
   The concept is simple actually. We see our brain's interpretation of visible light coming through our eyes. Before the light reaches our eyes it hits the objects, people, and places we see and then hits our eyeballs at approximately 186,282 miles per SECOND. So, we actually see a slightly delayed image of our world.
   It is this delay that the cloak seeks to exploit. Basically, this cloak or material will slow down the light headed toward the observer, essentially delaying the images of whatever is to be hidden. Yes, the speed of light is constant, but it can slow down depending on the material that it passes through. In fact, researchers have slowed light down to a snail's crawl of 38mph.
   But the slowing of light must be carefully controlled to manipulate the time delay. Alasdair Wilkins describes the theoretical process well:

   "Let's say you're standing a mile away from an observer. You start slowly decreasing the speed of the light traveling towards the observer so that it's only traveling at 60 miles per hour, or a mile per minute. Since you're slowing the light down gradually, the observer won't be able to perceive the change. Once the light has reached 60 miles per hour, the observer is now seeing you as you were one minute ago. You've now created a one minute spacetime corridor. You've now got a minute to do whatever you want without the observer having any idea what you're up to."

   "Once your minute is up, you switch off the machine slowing down the light, it speeds back up, and the observer now sees you again as you are right now - or at least as you were a nanosecond ago. That minute is a temporally compressed blip that the observer cannot perceive."

   So cool right? I think so. Just the very thought of compressing a minute's worth of actions into an undetectable segment of time and virtually erasing it from history is absolutely mind blowing. But, wouldn't that history be your own memory therefore making it actual history? Maybe it would actually compress history, which is difficult to think about too. Now the question is how to make the 'invisibility machine' invisible, because it's no use if you wheel a heavy hunk of 'light-slowing' material in front of the security cameras before you disappear. Hmm...

Sources:
http://news.nationalgeographic.com/news/2011/07/110711-invisibility-cloak-events-space-time-bank-robbery-science/

http://io9.com/5691060/spacetime-invisibility-cloaks-can-hide-entire-events-inside-temporal-voids