Re: lorenz transformation and spped of light

On Sep 20, 1:56 pm, "JM Albuquerque" <jmDO...@xxxxxxx> wrote:
"PD" <TheDraperFam...@xxxxxxxxx> escreveu na mensagemnews:1190313918.758640.271960@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx





On Sep 20, 9:18 am, "JM Albuquerque" <jmDO...@xxxxxxx> wrote:
"Jeckyl" <no...@xxxxxxxxxxx> escreveu na
mensagemnews:13f3hjam48l0218@xxxxxxxxxxxxxxxxxxxxx

"Chrisd5000rouge" <christian.d...@xxxxxxxxxxx> escreveu na mensagem
news:1190239831.214123.110060@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

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.

Of course it's a perception, 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?

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.

So we know what the reality is.

That's what it is in one frame of reference. What you apparently
assume, but haven't convincingly argued is:
- that if they have a relative velocity of 1.6 c in one frame of
reference, then this must be the relative velocity in any other frame
of reference;

No.
One has to account for direction.
I cannot say they have a relative velocity of 1.6c, because I'm
in the center and they got opposite directions.
I cannot sum their velocities because the right result will be:
0.8c + (-0.8c) = 0

Their *relative* velocity in this frame is zero? Then how do they ever
get further apart? Are you SURE you want to say that?

Hint: Even classically, the relative velocity is taken to be the
*difference* between two velocities, which in this case is the
difference between a positive number and a negative number, accounting
for directions. Now, tell me sir, what's the *difference* between +15
and -23?


and/or
- this is the frame of reference that determines what *reality* is,
and if other frames of reference do not result in the same number,
then those cannot be ascribed to *reality*.

Many realities I presume.
Each observer has its own "reality" with it.
And we cannot got out of that circular reasoning to say
who's got the supreme reality.

Precisely. So what you've said about this frame representing "true
reality" doesn't seem to hold much water, does it?

PD

.

Relevant Pages

  • Re: lorenz transformation and spped of light
    ... So we know what the reality is. ... That's what it is in one frame of reference. ... then this must be the relative velocity in any other frame ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... I cannot say they have a relative velocity of 1.6c, ... Each observer has its own "reality" with it. ... in any other frame. ... Two spacecrafts running at opposite directions at 0.8c each. ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... I cannot say they have a relative velocity of 1.6c, ... Each observer has its own "reality" with it. ... in any other frame. ... Two spacecrafts running at opposite directions at 0.8c each. ...
    (sci.physics)
  • Re: lorenz transformation and spped of light
    ... I cannot say they have a relative velocity of 1.6c, ... Each observer has its own "reality" with it. ... in any other frame. ...
    (sci.physics)
  • Re: Calculazions within a inertial system.
    ... fly with 0.9 c in opposite directions. ... What is their relative velocity as judged on in this inertial system? ... I think the relative velocity is +/- 1.8 c because i do not change the ... Now, for extra points, what is the speed of B judged from a frame ...
    (sci.physics.relativity)