On Mar 11, 2:08*pm, "
wrote:
Hello again,

Assume I take a spaceship to Alpha Centauri, which is 4 light years
away. And the ship goes so fast, that the travel time seems to me to
be one hour. Will it not seem to me that Alpha Centauri made a journey
that started at x=4[ly] and ended at x=0, during a time of one hour,
and therefore its speed was much faster than lightspeed? Where is my
mistake?

The answer is as follows:
The passage of 1 hour of spaceship time = the passage of 35040 hours
of earth time (or 4 years of earth time).
In other words, the spaceship is moving at a speed that give rise to a
gamma factor of 35040.
The following link explains this new concept.
http://www.geocities.com/kn_seto/2007IRT.pdf

Ken Seto