Re: FTL, ether and wind

On 16 veebr, 22:38, thro...@[EMAIL PROTECTED]
 (Wayne Throop) wrote:
> : Crown-Horned Snorkack <chornedsnork...@[EMAIL PROTECTED]
>
> : Let us imagine that we establish back and forth FTL signalling between
> : Earth and Alpha Centauri.
> :
> : These two are not exactly in the same inertial frame. However, the
> : relative speed is not relativistic.
> :
> : It is relatively easy to establish that a signal exchanged at the
> : speed of light travels for 8,6 years return trip.
> :
> : Once we establish FTL signalling, we can establish that round trip
> : time is exactly zero, and never negative.
> :
> : Now assume we then examine signals sent FTL one way and at speed of
> : light the other way.
> :
> : Suppose we establish that signals sent Earth to Alpha Centauri FTL and
> : back at the speed of light take 3,3 years, while the opposite takes
> : 5,3 years.
> :
> : Have we then observed ether wind?
>
> You've observed that your FTL seems to be occuring wrt a particular
frame,
> in which both earth and AC are in pretty brisk motion, something like
> 20 percent lightspeed (iicc).  This doesn't establish that that frame is
> the only frame in which FTL can occur, nor that this is an "ether wind",
> but it is certainly suggestive.

If you have multiple frames where FTL could occur, how do you avoid
time travel?

If in frame A, sending a signal FTL to Alpha Centauri and back at
speed of light arrive 3,3 years after departure

and in frame B, sending a signal FTL to Alpha Centauri and back at
light speed takes 4,3 years, as does sending a signal at light speed
to Alpha Centauri and back FTL

then a signal sent from Earth to Alpha Centauri FTL in frame A and
back from Alpha Centauri to Earth in frame B should arrive a year
before departure.

So we have time travel.