Re: lorenz transformation and spped of light

"JM Albuquerque" <jmDOTa2@xxxxxxx> wrote in message
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Two spacecrafts running at opposite directions at 0.8c each, the
lorenz transformation says that their relative speed perception is u=
(0.8c+0.8c)/(1+(0.8c*0.8c/c²))= 0.975c.

It not a "perception" .. it IS their relative speed (ie the speed of the
second spaceship in the iFoR of the first). SR doesn't talk about
optical
illusions :)

That's completely nonsense.

No .. its not

Of course it's a perception,

No .. its not

since the problem starts saying:
Two spacecrafts running at opposite directions at 0.8c each.
Why cannot the reality be that of two spacecrafts running at
opposite directions at 0.8c each?

It is

We build two spacecrafts, we place then back-to-back,
and we fire them with a program that guarantees that in
a given time and a given distance, both will be running
at 0.8c.

They do

So we know what the reality is.

In the stationary frame of reference .. yes

The value 0.975c is only a perception, not the reality.

No .. it is reality

Nevertheless, we can imagine that each spacecraft has a
pilote and that pilote wants to compute how much time will
it take to receive signals from the other spacecraft.
Each pilot, of each spacecraft can compute its absolute
speed relative to the distant fixed stars.

That is not absolute speed

Now, each pilot
wants to know where the other spacecraft is (what distance).
Both spacecrafts send light signals to each other.
Each pilot measures the redshift of those signals and
come up to the conclusion that such redshift indicates
a relative speed of 0.975c

No .. it has nothing to do with light signals. .the other space craft REALLY
IS travelling at 0.975c

Since each pilot knows its absolute speed from the
fixed stars to be 0.8c, it will be able to compute the
other spacecraft speed "x" to be that:
(x+0.8c)/(1+(x*0.8c/c²))= 0.975c.

So, that x = 0.8c.
Knowing its speed and the others speed, each pilot
can predict where in "reality" the other spacecraft is.

Yes .. and in reality the other craft is travelling at 0.975c in the first
spaaceship's iFoR

That's what SR is all about - RELATIVITY.
Not the reality.

SR is not about perception .. you seem to think that SR is just an optical
illusion.


.

Relevant Pages

  • Re: lorenz transformation and spped of light
    ... SR is not about perceptions and illusions. ... it is not about perception .. ... Why cannot the reality be that of two spacecrafts running at ... of each spacecraft can compute its absolute ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... It not a "perception" .. ... So we know what the reality is. ... it take to receive signals from the other spacecraft. ... Each pilot, of each spacecraft can compute its absolute ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... Of course it's a perception, ... That's the reality in one frame of reference. ... measured by the other real spacecraft. ... Each pilot, of each spacecraft can compute its absolute ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... It not a "perception" .. ... Why cannot the reality be that of two spacecrafts running at ... of each spacecraft can compute its absolute ... so there are as many speeds ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... That's the reality in one frame of reference. ... measured by the other real spacecraft. ... Measurements are measurements, not the reality. ...
    (sci.physics)