On 8 May, 00:06, HW@....(Henri Wilson) wrote:
On Mon, 7 May 2007 11:17:54 +0100, "George Dishman" wrote:
"Henri Wilson" HW@.... wrote in message ...

see:www.users.bigpond.com/hewn/bathgrating.jpg

Well done Henry. So your equation is

lambda_i * (c+u)
sin(phi) = ---------------
D * (c+v)

where lambda_i is the wavelength of the _incident_
light.

The wavelength of the reflected light, lambda_r, is
given by

lambda_r c+u
-------- = ---
lambda_i c+v

So your equation can also be written

lambda_r
sin(phi) = --------
D

You have been claiming that the speed didn't appear in
the equation and that wavelength couldn't change. One
or the other is wrong. You also claimed the formula
used frequency instead of wavelength but that too isn't
true. Naturally you can replace the wavelength by speed
over frequency but that just reintroduces speed in the
equation.

Desperate again George?

I'm having to teach you basic algebra yet again Henry.

Lambda_i is absolute and all we need.

Lambda_r doesn't enter into this.

Lambda_i isn't enough, if you want to use it you need
to know v and u as well but the grating doesn't measure
them. Remember all we know is the angle phi so you
can turn the second version round to get

Lambda_r = D * sin(phi)

but that's as far as you go. Your first equation isn't
usable because v and u aren't known so in BaTh a
grating doesn't measure Lambda_i, only Lambda_r.

The equation uses points of equal phase to calculate the angle of the wavefront
of the diffracted beam.

Yes, your basic equations are right but you are left
with two unknowns. Essentially the incident speed
and wavelength are 'conjugate' as you used the term
in relation to pitch and velocity in your simulation so
you don't know either. Going the extra step to express
it in terms of Lambda_r resolves the problem.

Let's assume that u =0, ie., the reflected light moves at c wrt the GRATING.

The result is as I said: Sin(phi)=D/lambda.(c/(c+v)), for 1st order
diffraction.

However knowing D and phi still leaves two unknowns,
lambda and v, so cannot be solved for either.

Speed is included in the equation....so the BaTh explains what is observed.

Lambda_r = D * sin(phi)

In the useable form, speed is not included in the equation.

SR does not.

SR gives the same equation but since we know the
speed is c we also have

Lambda_i = Lambda_r

in the frame of the grating.

The lesson Henry, is to work out the equation before you
start telling people what it contains.

The BaTh wins again.

Don't be stupid, both theories give the same equation.
However, in BaTh a grating cannot measure what you
call the 'absolute wavelength', only the reflected
wavelength. That's a limitation which suggests you
would need other instruments to find v and u.

The BaTh also explains sagnac.

Sagnac doesn't need an "explanation", it is a simple
measurement of OWLS from a moving source and the
result is c which falsifies Ritz's theory. There is a
superficial 'explanation' which I expected you to put
forward a couple of years ago but maybe you have
spotted the problem in it already. Anyway, as it stands
at the moment, you don't have a theory that is
compatible with Sagnac or the Shapiro delay.

The BaTh wins yet again.

Your obsession is getting the better of you, try to
calm down. For the grating (as for the MMX), both
theories give the same result and for Ives and
Stilwell, Sagnac and the Shapiro delay BaTh fails.

My point is simply that you guessed what the
equation would contain rather than working it out.
When you got round to it, I'm sure it only took a
few minutes but you have now discovered that your
assumptions were inaccurate, speed does not
appear in the final equation, only the reflected
wavelength:

Lambda_r = D * sin(phi)

You also suggested it used the frequency but that
also isn't true because you don't know c+u which
is needed to get frequency from Lambda_r.

George