Can information travel faster than light?

[Jan Brady]

In an experiment published in May 2000 (PRL v 81 n 21) wave packets
are observed to propogate faster than the speed of light by tunnelling
through barriers at rates faster than light would propogate through
vacuum over the same distance.

This is not a surprising result (if quantum mechanics is not
considered surprising) unless the wave packets can carry information
thus allowing information to travel faster than the speed of light.

The authors state "the question as to whether a wave packet can be
considered a signal is a much debated and complicated one." Does
anybody know any of the content or current status of this debate?

resummation

[Alex]

Jan Brady wrote:
> In an experiment published in May 2000 (PRL v 81 n 21) wave packets
> are observed to propogate faster than the speed of light by tunnelling
> through barriers at rates faster than light would propogate through
> vacuum over the same distance.
>
> This is not a surprising result (if quantum mechanics is not
> considered surprising) unless the wave packets can carry information
> thus allowing information to travel faster than the speed of light.
>
> The authors state "the question as to whether a wave packet can be
> considered a signal is a much debated and complicated one." Does
> anybody know any of the content or current status of this debate?
>
> resummation

According to John Baez "We discussed this issue to death!" (see
http://groups.google.com/group/sci.physics.research/browse_frm/thread/1097ad8df8f75872/12161831c53601df).
That is probably why people in this group do not want to pay attention
to your question.

It would not be fair to say that there is clarity in understanding of
these phenomena. A few papers on the subject can be found in IEEE
JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS, VOL. 9, NO. 1,
JANUARY/FEBRUARY 2003.

I would appreciate any fresh references.

[tttito]

Alex ha scritto:

...

> I would appreciate any fresh references.

Here is a nice short survey:

http://physicsweb.org/articles/world/16/12/3/1

IV

[Alex]

tttito wrote:

> Here is a nice short survey:
>
> http://physicsweb.org/articles/world/16/12/3/1
>
> IV

Thank you for the link. It points to new experiments and publications
by Stenner and others. Aephraim M Steinberg participated himself in spr
discussions on the subject in 1995.