In infinite wisdom David Woolley answered:

In article <e6KdnR6XHqa0NAPd4p2dnA@comcast.com>, stelv@comcast.net wrote:

 Ooh, Ooh, I have something I can add to this discussion!  I read about the experiment of FTL and if I remember correctly, no physical laws were violated, but apparently it is possible to send information faster than light, but not the matter or energy.

The limit is actually on the sending of information.  Also, energy has
mass

Energy has momentum, not mass.

so tends to be restricted by the same rules as conventional matter,

Err, no. Mass cannot travel at 'c', it can only travel at less than
'c'. Energy, on the other hand, can only travel *at* 'c'. The play
a different game and they play by different rules.

with the exception that, in certain cases, the mass is finite at c.

Maybe my math is off.

Let's see, m'         1
           - = --------------------
           m    sqrt( 1 - (v/c)^2)

You say that when v=c, m'/m is finite?

Seems to me that it's undefined at 'c' and approaches infinity as
v approaches c.

What have I got wrong?

True FTL communication would cause causaility problems as, to some
observers, reception would precede transmission.

How would the observer know this? Seems to me that this geometry is
not possible for anyone but a third party observing the transaction.

Anyone demonstrating real information travelling faster than c would be
in for a fast track Nobel prize.

Does the phrase 'spooky action at a distance' ring a bell? Physicists
have been saying things like this for decades.

The trouble with the various experiments that you read about is that they
are relatively cheap but make very could press release material for the
popular science press because of the popular fascination with the possibility
of the speed of light limit being broken from people who never read the
actual science papers from the exeriments, which generally explain that
there is no new theory (typically over 50 years old) and no challenge
to the speed of light limit on information transfer.

The experiments aren't actually controversial at all, but they do make
good headlines, and good headlines are probably good for funding.

I believe that you are referring to the fact that a group velocity can
travel faster than 'c'.

Rich