Last week, Chinese scientists successfully teleported what was effectively a packet of information (though technically far more complicated than that) from a surface based laboratory to a satellite in orbit some 870 miles overhead. While the term teleportation has been bandied about in headlines all over the internet in the days since, what these scientists actually accomplished is more akin to sending a telegraph than it is to beaming Captain Kirk into outer space… but don’t let that fool you. This development could have huge ramifications for communications technology here on earth, and out among the stars.
“People have this ‘Star Trek’ approach,” Bill Munro, a senior research scientist at NTT’s basic research laboratory, said. “They think of atoms being teleported. What we’re moving is information from one [quantum] bit to another [quantum] bit. There’s no matter — only information. That’s hard to get your head around.”
The experiment these scientists conducted involves an element of quantum mechanics Einstein once referred to as “spooky action at a distance.” In effect, two quantum entangled particles remain connected regardless of distance, and any action performed on one invariably affects the other. This sort of observable phenomena would likely seem like magic when the two particles are side by side, but the “spookiness” of this action compounds as the distances between the particles increase. Technically speaking, the way these particles interact with one another violates our understanding of physics – as one particle will demonstrate the effect of interactions with the other at any distance in real-time, even if it would take light significantly longer to cover that same gap.
Here is a cartoon NASA created to try to help people wrap their heads around this concept:
Harnessing this phenomenon for communications would mean a number of incredible advancements compared to how we transmit information today. Current communications are limited by the speed of light, which although pretty brisk at around 671 million miles per hour, is actually a significant hurdle when it comes to communicating across the huge expanses of space. The delay in a message we send to astronauts orbiting the moon would generally only be about 1.3 seconds each way, but when communicating with astronauts we hope to send to Mars, that delay grows to as much as 21 minutes. If we ever manage to send a crewed vessel out to Pluto’s neck of the woods, it would take a full five hours for your words to reach the crew’s ears, followed by another five-hour wait to receive their response.
This communications delay is a way of life for NASA scientists operating rovers like Curiosity on the surface of Mars. Each directive must be given, before waiting as much as 21 minutes to get the directive to the rover, and then another 21 minutes to receive confirmation from the rover that the message was received. Imagine trying to give your friend directions to the grocery store via text message, but having to wait a full 42 minutes between each step, and you begin to appreciate the time-consuming nature of space-based communications.
The Chinese team, led by Ji-Gang Ren at the University of Science and Technology in Shanghai, fired a ground based laser from Tibet directly at a satellite in orbit, and that laser carried a photon that was already entangled with one they maintained on the ground. They then entangled the photon on the ground with a third one, in order to measure any changes in their quantum states. Changes to the photons on the ground were then compared to changes indicated by the photon in orbit, in terms of their vertical and horizontal polarizations.
Currently, we wouldn’t be able to use these quantum shifts to transmit information, but they could be used as authenticators to allow us to know whether or not information had been eavesdropped on or interfered with, as any interaction with the entangled particles would be observable by all parties, but the theoretical concept could one day lead to a means to transmit simple data, like ones or zeroes, in real-time over any distance. Quantum communications currently sound like science fiction, but then, so did transporting an entangled photon to orbit with a laser, right up until last week.
This technology could one day make communicating with loved ones back home on earth as quick and simple as it is here, and because the information would be transmitted via entangled particles, it would be incredibly difficult to intercept or eavesdrop on, making for far more secure communications than currently employed via radio transmission. So, although we may be a long way away from getting to skip the rocket launch that brings us into space, this could mark an important step toward not making earth feel quite so far away once we leave. Perhaps even more importantly, this could make secure communications with space-based defense assets far more feasible, reliable, and prompt.
After all, what good is the Starship Enterprise’s massive view screen if your conversations are filled with waiting days or weeks to send and receive responses?
Image courtesy of NASA