On Sun, 14 Sep 2003 20:20:22 -0400, Rod Ryker wrote:



Mark Szlazak wrote:
Rod Ryker wrote in message ...

Rod: Oh? Why do you run from this argument?
Or is that drivel all you have to offer?
Just curious. GRIN


I see nothing in the set-up that provides a way to communicate at
faster than light speed.

Rod: Not necessary either.

The best that any causal influences propagates is the speed of light.

Rod: Yes indeed.

Even synchronizing the clocks. Clock
L doesn't cause clock R to read the same at the same relative time.

Rod: True, L has no power over R at all.
And relativity is irrelevant.
The times and lengths are ideal absolutes.

The setting is due to prior causes, i.e, the propagation at light
speed of the portions of the light beam that "hit" the clocks.

Rod: Yep. Henri should have the lasers on all the time.
Very good point!
How 'bout it Henri?

The lasers ARE on all the time. I thought I made that clear. They are only used
for precisely detecting position.
They are very close to the clock photocells so that delay is negligible. It is
the same for both anyway.

We can calculate the positioning accuracy.
If the rod moves at 10^4 m/s and both the laser beam and the photocell slits
are 1 micron, then the (time) width of the pulse received is 10^-10 secs. Its
shape is a perfect sawtooth so very accurate location and timing can be
ascertained in this way.


Rod Ryker...
It is reasoning and faith that bind truth.




You can arrange things the same way with a rod with pawls and ganged
clocks as discussed in Epsteins book pp 71-72. It also shows that
simultaneity is relative in this case. I don't have time now but I
will reproduce the pages here within a day or two.

I also found it strange that SR isn't about light or signalling.


Henri Wilson.

See my animations at:
http://www.users.bigpond.com/HeWn/index.htm

(HenriWilson) wrote in message . ..
Two clocks synched absolutely and connected by a long rod can determine whether
or not light always takes L/c seconds to travel the length of the rod.

This can involve a light source that is moving wrt the rod and emits a pulse of
light when it is exactly adjacent to one clock.

Yes, that could determine OWLS and if OWLS differed in opposing
directions but always gave a constant round-trip time then that would
have theoretical some implications. On the other hand, if OWLS was
equal in opposing directions that too would have some theoretical
implications. But both of these are on the "conventionality of
simultaneity" within a frame.

Nevertheless, we're talking about SR and its relativity of
simultaneity which is between frames and in that context you have
nothing inconsistent with SR! There is no "absolute" simultaneity as
the post on ganged clocks from Epsteins book shows.

(HenriWilson) wrote in message . ..
No. That is nothing like my method. Lengths do not physically change due to
movement.

Contractions are visual illusions.

It seems exactly like your method, but instead of laser beams
extending perpendicularly from the rigid rod it uses rigid extensions
of the rod itself.

The only difference is your claim about lengths not changing which
contradicts what the book and SR says.

Another puzzle to me is how measurement, visual or otherwise, isn't
also an illusion in getting initial values for you set-up. Why would I
ascribe priority or greater importance to these "visual illusions"?

On 15 Sep 2003 07:55:08 -0700, (Mark Szlazak) wrote:

(HenriWilson) wrote in message . ..
No. That is nothing like my method. Lengths do not physically change due to
movement.

Contractions are visual illusions.

It seems exactly like your method, but instead of laser beams
extending perpendicularly from the rigid rod it uses rigid extensions
of the rod itself.

The only difference is your claim about lengths not changing which
contradicts what the book and SR says.

Another puzzle to me is how measurement, visual or otherwise, isn't
also an illusion in getting initial values for you set-up. Why would I
ascribe priority or greater importance to these "visual illusions"?

see my animation: http://www.users.bigpond.com/HeWn/movingrod.exe

Henri Wilson.

See my animations at:
http://www.users.bigpond.com/HeWn/index.htm
My latest: http://www.users.bigpond.com/HeWn/movingrod.exe

Thanks Paul. My appologies, I didn't mean to imply that there was any
instantaneous communication between the clocks, in fact I thought that
I was demonstrating just the opposite. I'm slowly going through
Epsteins book. It seems to really go through all this stuff very well,
at least from the perspective of a Chiropractor. Amazon ratings are
all five star and a few look to be from some physics profs.

On Mon, 15 Sep 2003 22:44:34 -0400, Rod Ryker wrote:



HenriWilson wrote:
On Sun, 14 Sep 2003 20:20:22 -0400, Rod Ryker wrote:



Mark Szlazak wrote:

Rod Ryker wrote in message ...


Rod: Oh? Why do you run from this argument?
Or is that drivel all you have to offer?
Just curious. GRIN


I see nothing in the set-up that provides a way to communicate at
faster than light speed.

Rod: Not necessary either.


The best that any causal influences propagates is the speed of light.

Rod: Yes indeed.


Even synchronizing the clocks. Clock
L doesn't cause clock R to read the same at the same relative time.

Rod: True, L has no power over R at all.
And relativity is irrelevant.
The times and lengths are ideal absolutes.


The setting is due to prior causes, i.e, the propagation at light
speed of the portions of the light beam that "hit" the clocks.

Rod: Yep. Henri should have the lasers on all the time.
Very good point!
How 'bout it Henri?


The lasers ARE on all the time. I thought I made that clear. They are only used
for precisely detecting position.
They are very close to the clock photocells so that delay is negligible. It is
the same for both anyway.

We can calculate the positioning accuracy.
If the rod moves at 10^4 m/s and both the laser beam and the photocell slits
are 1 micron, then the (time) width of the pulse received is 10^-10 secs. Its
shape is a perfect sawtooth so very accurate location and timing can be
ascertained in this way.

Rod: Sorry Henri, I did not read all of your posts re this thread.
If they are always on, then I agree with you 100%.

I have written a program to animate the experiment so that it is easier to
understand.
See http://www.users.bigpond.com/HeWn/movingrod.exe

Takes only a few seconds.


Rod Ryker...
It is reasoning and faith that bind truth.


You can arrange things the same way with a rod with pawls and ganged
clocks as discussed in Epsteins book pp 71-72. It also shows that
simultaneity is relative in this case. I don't have time now but I
will reproduce the pages here within a day or two.

I also found it strange that SR isn't about light or signalling.



Henri Wilson.

See my animations at:
http://www.users.bigpond.com/HeWn/index.htm


Henri Wilson.

See my animations at:
http://www.users.bigpond.com/HeWn/index.htm
My latest: http://www.users.bigpond.com/HeWn/movingrod.exe

"Paul B. Andersen" wrote in message
...

"Mark Szlazak" skrev i melding
om...
It seems exactly like your method, but instead of laser beams
extending perpendicularly from the rigid rod it uses rigid extensions
of the rod itself.

Indeed.
There is no reason to use laser beams, a mechanical device
can work equally well in this thought experiment.
(The real experiment isn't feasible in either case.)
And all this talk about "instant communication" is way off
the mark, the opposite ends of the rods doesn't communicate
with each other.

It is a very simple problem to find what SR predicts for
this scenario, and if you understand the first thing of SR,
you should be able to find it yourself.

Let L be the proper length of the rods,
and v the relative speed between them.
The right clock will show a time (L/v)*(1 - sqrt(1-v^2/c^2))
less than a clock which is e-synched to the left clock,
that is, it isn't synched at all. And the offset from synch
depend on the speed and length of the rod.
If you measure the OWLS with those clocks, you can
measure anything you want by chosing the speed of the rod.

Then why is the speed of light measured to be c with e-synched clocks?

The only difference is your claim about lengths not changing which
contradicts what the book and SR says.

Indeed.
But this "only differece" IS the difference between
the Galilean transform and the Lorentz transform.

Henry Wilson insists there is no Lorentz contraction,
no relativity of simultaneity, and time is absolute.

What Henry claim is correct to a limited extend. Lorentts contraction is
apparent. It can be represented by a better explanation that the rod remain
the same physiccal length in all frames of reference but the light path
length of the rod varies according to the state of motion of the rod
relative to the observer.
There is no Relativity of Simultaneity. Both the train observer and the
track observer will see the lightning strike to be simultaneous but the
track observer will see the simultaneity at an earlier time. Why?Because the
light path length in the track is shorter. Notice that this explanation has
the same end result as the concept of RoS and that's why the SRians insist
that RoS is correct.
There is absolute time. The speed of light is a constant math ratio of light
path length over the absolute time content for a clcok second as follows:
Light path length of rod (299,792,458 m)/the absolute time
content for a clock second co-moving with the rod.

Ken Seto

"kenseto" skrev i melding ...

Both the train observer and the
track observer will see the lightning strike to be simultaneous but the
track observer will see the simultaneity at an earlier time.

You are determined to kill me, are you?
One of these days, you will.

Paul, gasping

"Paul B. Andersen" wrote in message
...

"kenseto" skrev i melding
...

Both the train observer and the
track observer will see the lightning strike to be simultaneous but the
track observer will see the simultaneity at an earlier time.

What so strange about this statement? If you LT the track's transit time
into the train frame you will find that it is less than the transit time in
the train. Therefore the simultaneity will occur in the track at an earlier
time.

You are determined to kill me, are you?

Why would I want that? What you need to do is to get rid of your mind set
that observed relative motion will affect the transit time in the train
differently in different directions. It doesn't. The SR postulate says so.

One of these days, you will.

I hope not. If you die it's not my false. You would be dieing of your own
ignorance.

Ken Seto

On 16 Sep 2003 11:39:28 -0700, (Mark Szlazak) wrote:

(HenriWilson) wrote in message . ..
Henri Wilson.

See my animations at:
http://www.users.bigpond.com/HeWn/index.htm
My latest: http://www.users.bigpond.com/HeWn/movingrod.exe

I'm sorry Henri, I see nothing different there than from what I've
posted. Paul's comments are right on the mark.

Anyway, I'll let the readers decide and for those non-physics types
like me I do very much recommend Epstein's book "Relativity
Visualized". It's virtually got no math, does everything with easy to
understand language and examples and includes GR as well. It starts
with Galileo, goes to the phenomena that need to be explained - e.g,
light invariance, how Einstein in SR makes the concepts of space and
time relative / changing instead of absolute and keeps light constant
to explain these phenomena (cool stuff), counterintuitive consequences
and how these are measured (more cool stuff), and the difference
between "seeing and measuring", the "visual illusions" that are
accounted for and those phenomena that arise directly from the basics
of the theory.

What you don't understand is that OWLS has never been measured.
There is no evidence at all that it is universally constant.
TWLS has been measured many times and found to be apparently constant only to
within about 1 part in about 10^9 which tells us nothing since the term (v/c)^2
is the expected order of the difference between OWLS and TWLS.

Relativity describes the geometry of space as it would have to appear if OWLS
was truly constant and equal to TWLS. As a theory, relativity is on par with
Earth centrism. It makes a relatively simple analysis extraordinarily
difficult.


Henri Wilson.

See my animations at:
http://www.users.bigpond.com/HeWn/index.htm
My latest: http://www.users.bigpond.com/HeWn/movingrod.exe