Re: Rel. Speed
- From: "Androcles" <Engineer@xxxxxxxxxxxxxxxx>
- Date: Thu, 28 Jun 2007 12:53:24 GMT
"razyrel" <razyrel@xxxxxxxxxxxxxxxxxx> wrote in message
news:f5v5pe$4ik$1@xxxxxxxxxxx
: Suppose a spaceship is moving at a constant speed of 0.8c.
Can't suppose it, you have say what the speed is relative too.
Certainly it would have speed zero relative to another spaceship
travelling alongside.
: Then the ship sends a pulse of light to the same direction as of the ship.
: Questions:
: a) Will the speed of this pulse of light be c or c-0.8=0.2c ?
Relative to the ship, c.
: b) How is it to interpret from the ship's frame of reference?
The ship has zero velocity with respect to its own frame of reference.
: c) How is it to interpret from the frame of reference of a stationary
viewer
From the ship's PoV she's not stationary at all, she's moving toward theship
at -0.8c. As far as she's concerned the light moves toward her at 1.8c.
"But the ray moves relatively to the initial point of k, when measured in
the stationary system, with the velocity c-v" -- Einstein.
1 - (-0.8) = 1.8
http://www.fourmilab.ch/etexts/einstein/specrel/www/ -- section 3.
: who is in a distance at a right angle parallel to the ships route when
: the light knob was pushed?
I don't understand that question or its relevance.
.
- Follow-Ups:
- Re: Rel. Speed
- From: Jeckyl
- Re: Rel. Speed
- References:
- Rel. Speed
- From: razyrel
- Rel. Speed
- Prev by Date: Re: Is space-time real?
- Next by Date: Re: GR: 'Line-of-sight' distance to a black hole is infinite?
- Previous by thread: Re: Rel. Speed
- Next by thread: Re: Rel. Speed
- Index(es):
Relevant Pages
|
|
