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Story: Future fibre networks to exceed light speed?

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Posted by: Rupert Goodwins (Tuesday 21 August 2007, 11:39 AM)

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Speed of Light Not Constant Anyway

"The reply to this constructive criticism was the transmission of classical music at FTL."

If you're referring to the experiments Professor Nimtz did at the U of Cologne, sending Mozart via microwave tunnelling, then they in no way contract special relativity (and I don't believe Prof Nimtz claims that they do). As far as I'm aware, no tunnelling experiment has shown >c, nor would it be expectd to, for information or energy. Group and phase velocity _can_ be >c, as SR allows, but can't be used to transfer anything useful.

The speed of light isn't an arbitrary, mysterious limitation. It's part of the geometry of space and time. You can no more go >c than you can go from London to Edinburgh in 40 miles rather than 400 (unless you fold the British Isles with the crease somewhere near Manchester - the analogy in physics is then the wormhole theory, which doesn't break c but does bypass it).

The thing that matters for tunnelling experiment velocity measurement - which is by no means an obvious thing - is the wavefront, the first hint that something's coming. In every experiment i know of, wavefront velocity does not contradict SR - but if you have specifics, I'd love to see them.

We're actually very good at modulating quanta! I suggest you look up what's been happening with quantum key distribution and entangled photon pairs, where we use polarisation as our medium. A further exercise to the reader: with quantum key distribution, how do you build a repeater? Could you use tunnelling?

Rupert Goodwins

Rupert Goodwins
Location, location, location
Member since: October 2006

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