Re: HOCUS POCUS


"Randy Poe" <poespam-trap@xxxxxxxxx> wrote in message
news:1158156888.813612.156190@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

mluttgens@xxxxxxxxxx wrote:
PD wrote:
mluttgens@xxxxxxxxxx wrote:
HOCUS POCUS

Two electrons E1 and E2 are ejected along a straight line with
opposite velocities v1 and v2 from a device stationary in S,
at t=0 according to S clock.

Assuming that v1 = -0.6 c and v2 = 0.8 c, what is the relative
velocity between E1 and E2 ?

After a time interval t measured on his clock, S will conclude
that the distance separating E1 from E2 is (0.6 + 0.8) ct = 1.4 ct,
hence that E2 is moving away from E1 at V = 1.4 c, or that E1 is
moving away from E2 at V = 1.4 c, meaning that the relative velocity
between E1 and E2 exceeds c.

Yes, and there is nothing wrong with that.


Ein Zwei Ein Stein HOCUS POCUS
E1 = S',
V = (.8 c-(-0.6c))/(1+0.8*0.6) = 1.40/1.48 c = ~.9459 c
E2 moves at 1.4/1.48 c relative to S'
E2 moves at 1.4/1.48 c relative to E1
ABRACADABRA
420000 = ~283784

By assimilating E1 to a frame S' moving away at -0.6 c from a frame
S,
Srists claim that the electron E2, which had a velocity V = 1.4 c
wrt E1 measured in S, has only a velocity V' = ~0.9459 c measured in
S'.

Yes.


But the electrons don't bother about which name they are given, nor
does their relative velocity V depend on their velocity wrt the
device
by which they have been emitted. Such device -the frame S according
to SRists- should be ignored after their emission, it belongs to
history.

Not at all. You seem to think that relative velocity between two
objects should be a frame-independent quantity. It's not. I don't know
why you think it should be.


I am skeptical about the physical validity of a formula (the
relativistic addition of velocities), which gives an infinity of
solutions for a same velocity V between to objects, for instance
1.4 c, measured in one frame (S in my example).

Because you have divine knowledge that separation rate
is independent of reference frame?

Well, the rest of us without divine knowledge are stuck
with describing what we see in experiment, which
is that the Lorentz transform is valid.

There's nothing I can do about the fact that your
divine knowledge contradicts experiment, that there
is some unknowable "reality" different from my
observable universe and accessible only to you.

So I'll stick with the equations that describe life
in my universe.

Let's consider a planet inhabited by advanced ET's, situated at
x billions light-years from the Earth. Their physicists, from the
redshift of the Earth galaxy A and the Hubble constant, calculate that
the Earth is moving away from them at -0.7 c. Opposite the Earth,
they observe another galaxy B, whose velocity relative to them is
+0.7c.
They conclude, in accordance with the cosmic expansion, that such
galaxy has a velocity 1.4 c relative to the Earth.

No, they conclude that those two points are separating
IN THEIR REFERENCE FRAME at 1.4 c.

This shows me that you don't understand relativity. In relativity those two
points are separating IN THEIR REFERENCE FRAME at less than c.....in this
case ~.94c.



.

Relevant Pages

  • Re: Natural Philosophy - Its challenge to SR
    ... ABSOLUTE, or UNIVERSAL, reference. ... If there are some laws of nature that are functions of absolute velocity, then we probably can measure our velocity by again measuring the laws of nature, and since we could obtain this velocity without having to use local, non-universal objects, it would again be an ABSOLUTE velocity. ... Again, Newton knew of no such laws, and although he created the idea of an absolute reference frame, Newtonian mechanics technically does NOT need a single, privileged reference frame with an undefined origin. ... It is built on top of the principle of Relativity ...
    (sci.physics.relativity)
  • Re: Are there any civil anti-relativists?
    ... What on earth do you think the "principle of equivalence" ... Does it have anything to do with the "principle of relativity"? ... satellite with its slower clock. ... to compute the orbit and velocity. ...
    (sci.physics.relativity)
  • Re: Are there any civil anti-relativists?
    ... What on earth do you think the "principle of equivalence" ... Does it have anything to do with the "principle of relativity"? ... satellite with its slower clock. ... to compute the orbit and velocity. ...
    (sci.physics.relativity)
  • Re: Are there any civil anti-relativists?
    ... What on earth do you think the "principle of equivalence" ... satellite with its slower clock. ... to compute the orbit and velocity. ... function of reference frame. ...
    (sci.physics.relativity)
  • And now for something completely different.
    ... First time I've seen anything like this in print (even if ... Louis Essen re-states his view that Einstein's theory of relativity contains basic and fatal flaws. ... Scientists reasoned that, since light is an electromagnetic wave traveling through space with a velocity denoted by the symbol c, and the earth is traveling through space with a velocity v, it should be possible to measure v by an optical experiment carried out in the laboratory. ...
    (sci.physics)