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Can information travel faster than light?


The Possibility of Superluminal Data Transfer
This diagram shows the process of four-wave mixing. Seed pulses of laser light alongside a pump beam are sent into a heated cell containing atomic rubidium vapor, which amplifies the seed pulses and enables them to achieve superluminalality.
This diagram shows the process of four-wave mixing. Seed pulses of laser light alongside a pump beam are sent into a heated cell containing atomic rubidium vapor, which amplifies the seed pulses and enables them to achieve superluminalality.
Image courtesy of NIST

Scientists at the National Institute of Standards and Technology (NIST) are claiming to have achieved faster-than-light transfer of quantum data using something called four-wave mixing, which incidentally is a phenomenon that's considered a form of interference in fiber optic lines. The experiment involves sending a short 200-nanosecond seed pulse through heated rubidium vapor and at the same time sending in a second pump beam at a different frequency to amplify the seed pulse. Photons from both beams interact with the vapor in a way that generates a third beam. Apparently, the peaks of both the amplified seed pulse and the newly generated pulse can exit faster than a reference beam traveling at the speed of light in a vacuum. The speed differences they reported were 50 to 90 nanoseconds faster than light through a vacuum. They even proclaimed being able to tune the speed of the pulses by altering the input seed detuning and power.

Another fast data transfer technology in the works is quantum teleportation, which relies on the existence of entangled pairs: two particles that are in tune with each other to the point that if you measure one, the other ends up with the same quality that you found in the first one, no matter their distance from one another. This also requires a third particle that contains the actual bits of data you are trying to transfer. A laser is used to teleport one of the entangled particles elsewhere, in a manner of speaking. It isn't really transporting a photon, but rather changing a new photon into a copy of the original. The photon in the entangled pair can be compared to the third photon to find their similarities or differences, and that information can be relayed to the other location and used for comparison with the twin particle to glean the data. This sounds like something that would result in instant transfer, but that's not the case. Laser beams only travel at the speed of light. But this has potential applications for sending encrypted data via satellite, and for networking quantum computers, should we ever invent them. And it's further along than any attempts at superluminal data transfer. It works over miles at this point, and researchers are trying to increase the teleportation distance.

The answer to whether meaningful information can travel faster than light is currently no. We're only at the level of moving a few quantum particles at speeds that may possibly be over the speed of light, if the data pans out on subsequent experiments. To have a practically applicable form of data transfer, you have to be able to send organized bits of data that mean something, uncorrupted, to another machine that can interpret it. The fastest transmission in the world will mean nothing otherwise. But you can be sure that if the speed of light is broken, we'll be applying it to our Internet transmissions far sooner than to interstellar travel. Our ability to watch the highest quality television and surf the net at the fastest speeds will be paramount. And perhaps for those purposes, even getting ourselves to truly as-fast-as-light transmission would do wonders.


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