Of all the weird, uncanny, anti-intuitive phenomena of quantum mechanics, entanglement might just be the most unbelievable. It defies every intuition we have about space and distance; it challenges us to consider that distance might actually be a figment of our imaginations, that space might be unreal on the quantum level.
It involves two seemingly independent particles that, despite sharing an origin, have found themselves separated by unfathomable distances. But due to a quirk of their shared origin, these two particles remain instantaneously linked. If you were to tickle only one of them and alter its spin, the other's spin would also get altered at exactly the same time, even though they might exist light-years apart.
This isn't some sort of magic trick. It has been impeccably studied and verified as a real phenomenon. In fact, scientists now know how to get two particles to become entangled, and they are beginning to experiment with how to transmit information instantaneously over large distances by manipulating this mysterious process.
In fact, scientists have now managed, for the first time, to produce entangled photons — particles of light — on a satellite orbiting 300 miles above the planet. Those particles were then successfully beamed back down to Earth to two different ground-based labs that were 750 miles apart. And the particles remained entangled throughout the entire endeavor, reports the Washington Post.
“It's a really stunning achievement, and I think it's going to be the first of possibly many such interesting and exciting studies that this particular satellite will open up,” said Shohini Ghose, a physicist at Wilfrid Laurier University in Canada. “Who knows, maybe there’ll be a space entanglement race?”
The experiment was completed by Jian-Wei Pan, a physicist at the University of Science and Technology of China in Shanghai, and colleagues, and the satellite where the entanglement happened was named Micius, a Chinese orbiter. The previous record holder for the distance that two entangled photons were kept without losing their entangled state was 86 miles. Needless to say, the 750 miles achieved by this experiment represents a huge step forward.
The main reason for such a significant advancement is the fact that the entangled particles were beamed from space. All other experiments were done here on Earth, where fiber optic cables are necessary for transporting the particles to their desired separate locations. Because fibers absorb light as photons pass through them, the entangled state slowly gets unraveled the further the particles travel apart from one another. In the vacuum of space, however, light doesn't get absorbed, so by setting up the experiment in orbit, the particles could be beamed further without losing any of their connection.
A breakthrough for communication
Next, Pan wants to try even more ambitious experiments, like sending quantum particles in the opposite direction, from the ground to the satellite. A distribution channel moving in both directions could allow for transmission of tens of thousands of entangled pairs per second.
The main advantage of this sort of quantum highway, should it be possible to develop one that is stable and reliable, is momentous. Quantum entanglement allows for instantaneous communication, so there's no way for hackers to cut in. And obviously, instantaneous communication is also blazing fast; nothing is as fast as instant.
Moving future experiments to space could usher in a whole new technological era faster than experts had previously projected. This could be the start of a quantum era where communication times become non-existent, and the very nature of the cosmos as we understand it could get turned on its head.
“That’s what makes it so mysterious and interesting,” said Ghose.