On May 5, 12:07Â*pm, YBM wrote:
rbwinn a écrit :

On May 5, 11:18�am, YBM wrote:
rbwinn wrote:
Einstein's own equations for
velocity of light do not work in the Lorentz equations if x or x' are
negative.
Wrong. They work.

No, they do not work. Â*Einstein said that x=ct, x'=ct'. Â*If x is
negative, then

Â* Â* Â* Â* Â* Â* Â* Â* Â*t'=(t-vx/c^2)/sqrt (1-v^2/c^2)

cannot be used with the equation x=ct. Â*The velocity of light has to
be -c in the equation for t' in order for the equation to work if x is
negative. Â* x=(-c)t, not x=ct.

Wrong.

Let's assume that x=ct

By LT we get :

x'= gamma*(x-vt)
t'= gamma*(t-vx/c^2) Â* Â*where gamma=1/sqrt(1-v^2/c^2)

let's have a look at x'/t' (*) under the condition that x=ct :

Â* x'/t' = (x-vt)/(t-vx^2/c^2) = (ct-vt)/(t-vct/c^2)
Â* Â* Â* Â* = t(c-v)/( t (1 - v/c) ) = c(c-v)/(c-v)
Â* Â* Â* Â* = c

= x'=ct'

(*) the case t'=0 is trivially ok (0=c0).

You neglect the fact that if x or x' is negative in the equations
x=ct, x'=ct', then either the velocity of light has to be negative or
time has to be negative. The equations you gave would apply only to
positive values of x and x', meaning that a photon is traveling in the
+x direction relative to the x axis. Where you scientists are making
a mistake is in saying CF = CB = C, such as when a photon is reflected
by a mirror. The velocity of the photon is changed from +c to -c
relative to the set of coordinates. The Lorentz equations compensate
for velocity of light automatically, which is why scientists like them
so much, in addition to their distance contraction, which scientists
seem to worship.
However, keeping velocities correct also allows use of the Galilean
transformation equations, which do not have a distance contraction.
If the velocity of light is shown to be c by two identical cesium
clocks, one in S and one in S', then this can be shown by the
equations

x=wt
x'=wn'

The time of the cesium clock in S' cannot be shown by t' because t' is
already defined to be t'=t in the Galilean transformation equations.

x'=x-vt
wn'=wt-vt
n'=t(1-v/w)

What is interesting about this equation is that it corresponds to
reality, which is that an observer with a cesium clock in S' which is
running slower than an identical cesium clock in S will perceive the
velocity of one frame of reference to the other to be higher as
measured by the slower clock in S' than as measured by the clock in
S. This makes it possible for a particle to be accellerated to the
speed of light as measured by atomic time in the frame of reference of
the particle, making the existence of light possible, as opposed to
the impossibillity of existence of light shown by the Lorentz
equations, since nothing can be accellerated to the speed of light.

n' in the above equation is actually the numerator of t' in the
Lorentz equations.

n'=t(1-v/w)= (t-vt/w) =(t-vx/w^2) = (t-vx/c^2)

It gives the same kind of difference in time without the distance
contraction. At a velocity of .9 c, if t= 1 sec., t' in the Lorentz
equations will be .23 sec. whereas, n' will be .1 sec. The faster
time of the Lorentz equation clock makes a distance contraction
necessary, whereas, n' corresponds to the Galilean transformation
equation value of x'. For slower velocities such as the velocity of
the planet Mercury, which was used to prove the accuracy of Einstein's
theory, n' agrees with t' in the Lorentz equations to several decimal
places.
In any event, the Lorentz equations show that nothing can be
accellerated to the velocity of light, whereas, the Galilean
transformation equations show that it is possible, making the
existence of light possible. However, it should already have been
obvious to scientists because without the existence of light, they
would not have been able to show with the Lorentz equations that light
can not exist.
Robert B. Winn