On 23 Feb 2007 02:48:36 -0800, "George Dishman"
wrote:

On 23 Feb, 09:39, HW@....(Henri Wilson) wrote:
On Thu, 22 Feb 2007 23:59:59 -0000, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
.. .
On Thu, 22 Feb 2007 10:17:35 -0000, "George Dishman"
Thanks to Jeff Root for pointing out my misunderstanding
of your definition.

You are still completely misunderstanding the whole thing.

I did misunderstand which angle your were describing
previously. Consider this where B is the barycentre
of the system, P is the pulsar, D is the Dwarf and E
is the Earth:

D
B E
P

I was saying you could neglect the angle P-E-B. Obviously
you still need to take the direction of the pulsar velocity
into account.

Yes OK.

The benefit was just that you then get the conventional
value as a simple confidence check by setting the distance
to zero.

I have checked.

No. We are not using a grating. Individual pulses have
their time of arrival noted against an atomic clock.
Remember they are 2.95 ms apart so the 'wavelength' is
885 km.

The inverse of the time between arrivals is the pulse
repetion frequency. That frequency is what is turned
into the published orbital parameters and is what give
the 339 Hz +/- 30 mHz values.

That's due to normal doppler 'bunching'.

No, it is what is observed. It results from a combination
of the normal bunching due to the varying distance from
Earth and also the catch-up effect.

There's NO 'catch up effect' in YOUR theory.

I know Henry, the program is supposed to simulate
the physics of ballistic theory.

BaTh bunching is virtually the same.

I told you, the program deliberately normalises the heights of the two
curves
to make shape comparison easier. If you like I will get it to plot a true
amplitude comparison.

That would help but what we need is the numerical
values.

Why? So you can plot them just as the computer does?

I can print out the values if you like.

Just the value at the peak. The purpose is to allow
the parameters to be adjusted until this value reads
27km/s so we know when we have a match.

I told you that the red curve is an average speed of the light that arrives in
a set time interval. I htink you can imagine the effect bunching has on that.

I don't want to imagine, I want the comuter to
do that for me.

......Explained in my other message.


OK we agree on that.

Consider two pulses transmitted just before and just
after the neutron star passes behind the dwarf as seen
from Earth. This is the point of highest acceleration
and the second catches the first at the maximum rate.

First consider no extinction. The diagram shows the
earlier pulse 'a' already ahead of 'b' at the time
when b is emitted:

b a
b a
b a
*
a b
a b

The time between pulses goes to zero at the critical
distance. Now add extinction:

b a
b a
b a
b a
b a
b a
b a

The 'wavelength' settles down to a constant value but
it is less than the original.

George, George....
Consider what happens to pulses emitted when the pulsar is at the sides of
the
orbit. ..where there is NO aceleration. They are also equally spaced for
the
whole journey.

Yes, at those points you only get the velocity effect
but at any other location in the orbit the spacing is
affected by both the velocity _and_ the acceleration.

BUT THE SPACING IS NOT THE SAME AS THAT BETWEEN THE FORMER ONES a and b.

In other words, the normal doppler pattern is there whether you use BaTh
or
constant c.

The normal Doppler is there of course, I haven't disputed
that, but it isn't the whole story. The pulse spacing is
also affected by what I describe above and you need to take
that into account AS WELL to get the full answer.

The program takes everything into account.
Why don't you experiment with it?

I have, it gives the wrong value because you only take
the bunching due to c+v vs c-v into account on the
brightness curve, not the velocity curve. The predicted
velocity is derived from the time between pulses so you
need to take into account there too.

Ah, I think I know what you are saying now.
You are claiming that the closer the bunching, the shorter the wavelength...and
the higher the observed doppler shift.

Yes that should be true for the pulsar...but it is not true in my program.....

So what is the difference?
The difference is that it is the change in the actual width of the pulsar
pulses in each bunch that is analogous to what my program does.
Do you see what I mean?
In reality, the width of the pulsar pulses varies by the same doppler fraction
as does the distance between pulses. (~90 parts per million)
So you have to average the WIDTHS of pulses and NOT their spacing to generate
your equivalent of my red curve.

The bunching itself is an indicator of brightness variation.

You have to include the difference in emission times of course.

Yes.

Note that this effect
is in addition to the normal Doppler change due to
velocity alone (but at the location we are considering
the radial speed is zero).

Yes assume that is zero.

Only at that point, I agree with your description above
that velocity plays a part elsewhere.

I'm becoming a bit confused as to what we are actually talking about now.

At any point arond the orbit, pulses are being
sent with a time gap of 2.95 ms. That gap is
reduced at the receiver for two reasons:

a) the velocity of the pulsar towards the receiver
means that consecutive pulses travel different
distances. That is the normal Doppler effect.

b) if the pulses are transmitted at different speeds
then faster pulses can 'catch up' to slower ones
reducing the gap (or 'fall behind' if the second
pulse is slower increasing the gap) and hence the
time between reception depends on how much of this
effect happens before extinction equalises the
speeds. This effect is not taken into account
in published velocity curves so the published
values will be higher or lower than the simple
Doppler value.

That effect is not indicative of source velocity.


Part (a) is dependent on the radial component of velocity
at the time of transmission, part (b) depends on the
acceleration at the same time and of course both vary
round the orbit. Your program includes effect (a) but
not effect (b).

You'll have to rethink this in light of what I have said.


George

"When a true genius appears in the world, you may know
him by this sign, that the dunces are all in confederacy against him."
--Jonathan Swift.