Why are the 'Fixed Stars' so FIXED?

On Mon, 19 Feb 2007 00:39:51 -0000, "George Dishman"
wrote:


"Henri Wilson" HW@.... wrote in message
.. .
On 17 Feb 2007 21:55:33 -0800, "Leonard Kellogg"
wrote:


Henri Wilson wrote:

Anyway, put the numbers into your program and tell
me what you get and then we can discuss their
interpretation. Check the results for zero distance
first and make sure you get the right speed and phase.

Naturally for zero distance I get no brightness variation.
The observed velocity is in phase with the true velocity.

You should still get a very small variation due to the
conventional bunching you reminded me of at the top.

Not if the observer is at the orbit centre.

He isn't saying to put the observer at the orbit centre, he
is saying to locate the observer just in front of the light
source so that your program output shows the effect of the
initial bunching of the pulses due to the changing position
of the star, but not the bunching which occurs in transit.

At each iteration, the observer is at zero distance from
the source, but is treated as being motionless, as usual.
It is as if there were 30,000 observers round the orbit,
each motionless relative to the orbit centre, but placed
immediately in front of the source.

If your program is unable to do that, you should be able to
put the observer at the near side of the orbit. Apparently
you have simplified the program to treat an orbiting star
as a reciprocating point, oscillating back and forth in the
line of sight. Just place the observer at the near end of
the stroke.

I can't see the point.
There wil be no opportunity for bunching and no brighness variation.
All I will see is conventional doppler frequency variation using constant
c.

That was the entire point of the exercise, to check
the code by confirming that your program gives the
conventional result when there is no opportunity
for bunching.

Of course it does. Do you think I'm stupid? (don't answer that:

George