The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.

See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/

"YBM" wrote in message ...
The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.

See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/

Nice one.
An excellent opportunity for Androcles to finally grasp it, but it will
not work. Let's hope he will finally lose whatever is left of his mind
over the abundant (but never named or even conceived) closing
speeds/velocities in there ;-)

Dirk Vdm

On Wed, 30 Apr 2008 16:43:25 +0200, YBM
wrote:

The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.

See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/



[Hammond]
Are you kidding.... nobody but a rank amateur would screw
around with algebraic formulas when adding velocities.
Any expert will tell you all you do to add two velocities
in SR is to

ADD THE RAPIDITIES STUPID

The rapidity is defined as:

rapidity = r =acrtanh (v/c)


If you want to add two velocities (2/3)c and (3/4)c, all
you do is add r1 and r2 and then take the tanh of the
result:

r1 = arctanh(2/3) = .80472

r2 = arctanh(3/4) = .97296

total = 1.7777

Vtotal = tanh(1.7777) = .94444 c

So, (2/3)c + (3/4)c = .94444 c

George Hammond a écrit :
Are you kidding.... nobody but a rank amateur would screw
around with algebraic formulas when adding velocities.
Any expert will tell you all you do to add two velocities
in SR is to

ADD THE RAPIDITIES

Fine. It's exactly what is proven there. I'd guess than no
expert would accept a statement without any proof of it,
wouldn't he ?

STUPID

Nice to meet you.

YBM wrote:
The following describes a very elegant and simple derivation of the
relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.

See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/


What about this one?

In S1, a body is moving with the speed u = dx/dt.
What is its speed w = dx'/dt' in S2 which is
moving with the speed -v relative to S1?

dx' = g(dx + v*dt)
dt' = g(dt + (v/c^2)*dx)

w = dx'/dt' = (dx + v*dt)/(dt + (v/c^2)*dx)
w = (dx/dt + v)/(1 + (v/c^2)*(dx/dt))
w = (u + v)/(1 + u*v/c^2)

--
Paul

http://home.c2i.net/pb_andersen/

In sci.physics.relativity, YBM

wrote
on Wed, 30 Apr 2008 16:43:25 +0200
:
The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.

See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/

An interesting and elegant derivation; my hat off to
the author. It also of course corroborates exactly with
the derivation done using the Lorentz (which I for one
have done previously).

--
#191,
Useless C++ Programming Idea #110309238:
item * f(item *p) { if(p = NULL) return new item; else return p; }
** Posted from http://www.teranews.com **

On Wed, 07 May 2008 13:14:43 +0200, "Paul B. Andersen"
wrote:

Dr. Henri Wilson wrote:
On Wed, 30 Apr 2008 16:43:25 +0200, YBM wrote:

The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.
See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/

It assumes the unproven second postulate is correct.

It is crap.... just like the postulate.

What does Fizeau's experiment show, Henri?

That BaTh is correct.

Doesn't matter since you don't believe in
experimental evidence anyway, eh?



Henri Wilson. ASTC,BSc,DSc(T)
www.users.bigpond.com/hewn/index.htm

.....specialising in teaching physics to engineers and mathematicians....

Dr. Henri Wilson wrote:
On Wed, 07 May 2008 13:14:43 +0200, "Paul B. Andersen"
wrote:

Dr. Henri Wilson wrote:
On Wed, 30 Apr 2008 16:43:25 +0200, YBM wrote:

The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.
See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/
It assumes the unproven second postulate is correct.

It is crap.... just like the postulate.
What does Fizeau's experiment show, Henri?

That BaTh is correct.

I see.
So according to the "BaTh", velocities transforms like this:
w = (u+v)/(1+uv/c^2)
which implies that the velocity c transforms like this:
w = (c+v)/(1+cv/c^2) = c

Why do you call your theory the "BaTh" when it is
identical to SR?

--
Paul

http://home.c2i.net/pb_andersen/

On Fri, 09 May 2008 12:24:54 +0200, "Paul B. Andersen"
wrote:

Dr. Henri Wilson wrote:
On Wed, 07 May 2008 13:14:43 +0200, "Paul B. Andersen"
wrote:

Dr. Henri Wilson wrote:
On Wed, 30 Apr 2008 16:43:25 +0200, YBM wrote:

The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.
See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/
It assumes the unproven second postulate is correct.

It is crap.... just like the postulate.
What does Fizeau's experiment show, Henri?

That BaTh is correct.

I see.
So according to the "BaTh", velocities transforms like this:
w = (u+v)/(1+uv/c^2)
which implies that the velocity c transforms like this:
w = (c+v)/(1+cv/c^2) = c

Why do you call your theory the "BaTh" when it is
identical to SR?

...the experiment was not sufficiently accurate to detect the difference between
the predictions of the two theories.



Henri Wilson. ASTC,BSc,DSc(T)
www.users.bigpond.com/hewn/index.htm

.....specialising in teaching physics to engineers and mathematicians....

Dr. Henri Wilson skrev:
On Fri, 09 May 2008 12:24:54 +0200, "Paul B. Andersen"
wrote:

Dr. Henri Wilson wrote:
On Wed, 07 May 2008 13:14:43 +0200, "Paul B. Andersen"
wrote:

Dr. Henri Wilson wrote:
On Wed, 30 Apr 2008 16:43:25 +0200, YBM wrote:

The following describes a very elegant and simple derivation of the relativistic
formula for the addition of velocities, w = (u+v)/(1 + uv/c^2).

It is due to David Mermin.
See:
http://dorigo.wordpress.com/2008/04/...ivistic-train/
It assumes the unproven second postulate is correct.

It is crap.... just like the postulate.
What does Fizeau's experiment show, Henri?
That BaTh is correct.
I see.
So according to the "BaTh", velocities transforms like this:
w = (u+v)/(1+uv/c^2)
which implies that the velocity c transforms like this:
w = (c+v)/(1+cv/c^2) = c

Why do you call your theory the "BaTh" when it is
identical to SR?

..the experiment was not sufficiently accurate to detect the difference between
the predictions of the two theories.

And the prediction of the BaTh for Fizeau's experiment is? :-)

--
Paul

http://home.c2i.net/pb_andersen/