Quantum tunneling is faster than light travel ? My reasoning is that the particle cannot be detected inside the tunnel so if it travels from A to B it must be instantly going from A to B , hence faster than light travel ?

This seems legit for the particle interpretation. And also for waves imho. Some people mention the uncertainty principle but I do not see how that explains it.


Faster-than-light tunneling appears only in non-relativistic quantum mechanics. As soon as you introduce the concept of relativity to QM, faster-than-light tunneling disappears.

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    $\begingroup$ Why is that so ? $\endgroup$ – mick May 5 '13 at 19:15
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    $\begingroup$ In relativistic quantum mechanics the Schroedinger equation is no longer valid. Instead, you have to use the Dirac or Klein-Gordon-equations. Those treat space and time at the same level (in terms of derivatives) and are covariant w.r.t. Lorentz transformations. $\endgroup$ – Neuneck May 6 '13 at 5:58

There are several experiments where photons are claimed to travel faster than the speed of light. Most notable among them are Nimtz double-prism experiment. Here is a bibliography on the subject.

As it is said in the link, physicists basically agree on the observations, but differ in the interpretations of those observations. Confusion between phase velocity and group velocity is usually the culprit.

But last time i checked, a time machine has yet to be done using such "FTL" transmission. Until that happens, i would attribute any such FTL-like behaviour to free human interpretation of things looking like information transfer, which really aren't so.


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