Image Credit: Heather Deal/Cornell University/AP Photo

There are many physicists who truly believe that time is merely the numerical order of change instead of it being an integral part of the space/time continuum (the 3 dimensions of length, width, and height, with time being a separate entity).  Essentially, the idea is that numerical order is not equivalent to temporal order, i.e., the number 1 does not exist before the number 2 in time, only numerically. This would have some interesting implications for us, of course, one of the primary implications would be on the very notion of time itself. But regardless of how time exists, it goes without saying that time has an absolute correlation between our perspective of the “then,” “now,” and “later” to the overall natural order of things. In this sense, it does not matter what time is, as we perceive it the same either way. Ultimately, this ‘absolute’ perception of time makes it incomprehensibly amazing to learn about a time cloak, a device that can tie together space-time principles with optical sciences.


The First “Time Cloak:”


In the early months of 2011, a team from Cornell University in Itaca – spearheaded by Moti Fridman – demonstrated the very first functional time cloak, originally cloaking an event for a mere 50 trillionths of a second. The team’s device used a technique called “temporal cloaking,” which can essentially tear small holes in space/time by manipulating a beam of light (photons carry information that can help the event be seen by the human eye) with more light using laser pulsars — cancelling light waves out, ultimately cloaking an event from sight as if it never occurred.


Credit: MTI Tech Review

Building off on the existing technology, researchers discovered a new way of cloaking time. The team took a beam of light, inserted it into a system equipped with fiber optic cables and a detector. After which, the team was able to cloak more than half of the data emitted into the beam’s path before pushing the light forward and back “using commercial telecoms components that are controlled by electrical signals,” said Andrew Weiner (a professor of electrical and computer engineering at Purdue University), who co-wrote the paper. “In temporal cloaking, we’re still talking about the control of the flow of light. But rather than steering it around spatial objects, we’re steering it forward and backward in time so it doesn’t overlap with events that happen in time.”



Understanding Temporal Cloaking:


Perhaps it would be easier understood if we make the manipulation of light into a metaphor, like a flowing river. “Think about taking a region of that river and pushing some of it forward, and some backwards so there are holes where there isn’t any water. Maybe there’s a dam, and we can pop the dam on and off very quickly, to somehow disturb or divert the water. If we part the water so it doesn’t see the dam popping up and down, it isn’t disturbed, and afterwards we can put the water back together so it looks like a nice calm river again. That’s how we control the flow of the light. We’re pushing it forward and backwards in time, so it avoids events that would otherwise disturb it,” Prof Weiner said. In doing so, “now we can change the way light, and thus information, behaves in space and time.”


This technology could have broad applications for sending encrypted data (it could even be more effective than a quantum network), but for the time being, it is not practical. It does too good of a job. Assuming we used this method to send a message, not only would it almost be as if it never happened, but the message itself would even be even cloaked to the intended recipient… meaning more work obviously needs to be done.



A Demonstration Showing How it Works:




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