Scientists Break Speed Of Light... Again

I'm pretty sure I've linked this same story thirty-seven times by now. And everytime I do the physics geeks say that the speed of light was not really broken, and, furthermore, this is a fairly old-hat thing by now.

I forget why they say that. It's nuanced. But hopefully they'll re-explain it. I'll of course forget it again by next time.

So, speed of light broken, again.

[T]wo German physicists now claim to have forced light to overcome its own speed limit using the strange phenomenon known as quantum tunnelling.

They set up an experiment in which microwave photons, energetic packets of light, appeared to travel "instantaneously" between two prisms forming the halves of a cube placed a metre apart.

When the prisms were placed together, photons fired at one edge passed straight through them, as expected. After they were moved apart, most of the photons reflected off the first prism they encountered and were picked up by a detector. But a few photons appeared to "tunnel" through the gap separating them as if the prisms were still held together.

Although these photons had travelled a longer distance, they arrived at their detector at exactly the same time as the reflected photons. In effect, they seemed to have travelled faster than light.

...

Quantum tunnelling is a well known phenomenon that occurs as a direct result of the strange uncertainty which pervades nature at very small scales. It allows sub-atomic particles to break apparently unbreakable barriers.

The German scientists mused upon the strange paradoxes of time-travel. "Imagine if you could go back in time to the moment right before Hitler came to power," one physicist hypothesized, before asking the famous question: "How cool would that be? You know, just to say 'What up, G?' And maybe just chill with him a couple of hours."

posted by Ace at 05:37 PM

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