Now a lot of this science is well beyond me (if you want to read about the research, you can check out the scientists’ article in Nature magazine), but bear with me while I try to explain it. An invisibility cloak makes objects invisible by warping light such that light travels around the object–that way, no light is reflected back into your eyes (and you don’t see anything). A time cloak, on the other hand, messes with the speed of light that would (in theory) be reflected into our eyes, so that we do not perceive the object or action until after it’s already happened.
The experiment was done by a team led by Moti Fridman of Cornell University, with support from DARPA, and it involved shooting lasers through a fiber optic cable. They managed to hide an event for 40 picoseconds (trillionths of seconds). Now, we’re a HUGE way off from using time cloaks to hide bank robberies, murders, etc. But the experiment does demonstrate that it might be possible to send data covertly through fiber optic cables.
Of course, the mind first jumps to using a time cloak as a plot device in a thriller–a thief steals something valuable but the guards don’t know until later, or an assassin can cloak the firing of a bullet. Heck, even repo men and cops would love to grab an item or a person without others perceiving it in order to minimize potential dangers. Even if it’s limited to data transmission, time cloaks would make for a great story. Spies, identity thieves, bank robbers (the electronic kind, not the stick-em-up kind) would love to get their hands on this technology.
But what really got to me was thinking about a world in which these devices are common and large scale (i.e., not just for data transmission). What would that do to your mind if you couldn’t trust your perception? What if, when you witnessed something, you knew it wasn’t in fact happening in front of you, because it had already taken place (the light from an action that took place a while ago is only now getting to your eyes)? The doubt, the fear, the paranoia that would create. Things might go from puzzlement to panic very quickly if suddenly large numbers of people were experiencing the equivalent of hallucinations. Or would it lead to depression and fatalism? How would you act if you began to think what you are seeing is less than real? Would it cheapen reality, leading some people to act out?
This seems very much like a Philip K. Dick story to me. What do you think? What do you think of time cloaks?