The experiment wasn't the first to show that local realism isn't how the Universe works — it's not even the first to do so with qubits. But it's the first to separate the qubits by enough distance to ensure that light isn't fast enough to travel between them while measurements are made. And it did so by cooling a 30-meter-long aluminum wire to just a few milliKelvin. Because the qubits are so easy to control, the experiment provides a new precision to these sorts of measurements.
So, long story short, quantum entanglement DOES transmit information faster than light.
In practice, this meant giving the entire assembly built to keep the wire cool access to the liquid helium refrigeration systems that housed the qubits at each end—and building a separate refrigeration system at the center point of the 30-meter tube. The system also needed flexible internal connections and exterior supports because the whole thing contracts significantly as it cools down.
Still, it all worked impressively well. Because of the performance of the qubits, the researchers could perform over a million individual trials in only 20 minutes. The resulting correlations ended up being above the limit set by Bell's equations by a staggering 22 standard deviations. Put in different terms, the p value of the result was below 10-108.
The distance traveled by the speed of light in a nanosecond is roughly a foot. Computers easily run at speeds that are measured in nanoseconds, making it possible to see the resulting measurements made of entanglement connecting one chip to the other faster than the speed of light. One chip reacts to the other sooner than light can travel 30 meters. By the look of that 10^-108, a hell of a lot faster.
So there you go, you -can- transmit information faster than the speed of light. Somewhere, Albert must be grumbling about it.
Update: Welcome Small Dead Animals! Thanks for the linkage, Kate!
3 comments:
Eh, I'm skeptical until it can be reproduced by another team on a different set of equipment. Last time we had reports of faster-than-light results from a physics experiment, it turned out that the clocks at the two ends were ever-so-slightly off. Just by a factor of microseconds or tenths of a microsecond, as I recall, but that was enough to produce the apparent faster-than-light result. Once the experiment was rerun with accurately-calibrated clocks, the particles turned out to be traveling at a speed just under the speed of light, not just over it as the previous experiment had shown.
On the other hand, this is quantum entanglement that's being discussed here, so it actually would be consistent with my (limited) understanding of quantum mechanics for FTL communication to be done via entangled particles. (As is a staple of many science-fiction settings, including yours). So I'm willing to accept this result as probably correct once it's been replicated. But until a second team replicates it on a different set of equipment, I'm going to hold open the possibility that the apparent FTL communication were caused by something else, such as an equipment misconfiguration. (For example, maybe one end of the system wasn't working at all, and those million individual trials in 20 minutes were only using half the system, but the system as a whole was twice as fast as they thought it was, therefore they thought they were getting performance out of the whole thing. That's one way I can think of for this to be a mistaken result; there may be others).
Interesting to watch, though. And certainly useful for your writing!
P.S. It looks like Blogger and Google still aren't talking to each other, so this comment will probably show up as "Unknown". It's by Robin Munn.
If they really want to prove it, take two pairs(A-B, C-D) of entangled qubits, and put one of the qubits from each pair (A, C) on a satellite and launch it to Saturn. Using one qubit (B), transmit info to the satellite to the other qubit (A), receive the info there, and send it through the other qubit (C) back to it's paired qubit (D) at the original source. If true, you should be able to send the info via qubit B and instantly receive it from qubit D. Light would take over an hour to travel from Earth to Saturn.
I'm commenting with a Google account. Yours may be an FTL problem, Robin...
Post a Comment