Why are the 'Fixed Stars' so FIXED?

On 19 Feb 2007 00:41:06 -0800, "George Dishman"
wrote:

On 19 Feb, 04:44, HW@....(Henri Wilson) wrote:
On Mon, 19 Feb 2007 00:36:42 -0000, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
.. .
On Sun, 18 Feb 2007 10:59:26 -0000, "George Dishman"
But you cannot ever get that because the variable
speed messes up the Doppler equation. As with any
modelling technique, you put in your initial guess
of the actual parameters, the program caclulates
the observed signals and then you iterate until
the predicted observables match that actuals.

Ah, but I only need a value for the MAXIMUM orbital speed.

Ah, but you cannot know that, all you know is the
maximum Doppler shift.

That's all I need.

Yes but you have to process it appropriately. Your
program is not doing that at present.

It's near enough to do what I want at present.... although I will have to take
Yaw angle into acount eventually..
All I am doing now is matching curves. The value of (distance x max velocity)
is rather arbitrary because I dont really know the unification distance and it
is not easy to obtain velocity diagrams.

The BaTh and SR
doppler equations are effectively the same.

No they aren't, that's the whole point. Look at the
bottom of your reply where you agree the _apparent_
speed should reach c at the critical distance!

Yes.... but during extinction, the wavelength contracts or expands, so as to
still maintain the correct details of source velocity.

No, the speed matching causes the 'wavelength',
which in this case is the distance between pulses,
to eventually settle down to a constant value but
it will not be the original.

Not according to me.
The final distance between adjacent pulses will vary according to their initial
velocity relative to the barycentre. Some will move closer together, others
further apart.

The extreme test
example here is for viewing at 8 light years with
negligible extinction, or equivalently at infinity
with an exponential extinction distance of 8 light
years, and the wavelength is zero. Your software
still gives v/c=0.00009 when it should be v/c=1.

George, unless I have access to a curve showing variation in pulse arrival
times I cannot help you much.

Reading the papers about this pulsar is quite confusing for me because the
authors make such a big issue of Shapiro delay. (They even admit light is
slowed by gravity). The BaTh interpretation would be quite different from
theirs.

I have removed most of the bugs although it doesn't have comprehensive
instructions as yet. Extinction doesn't work for circular orbits.

That's OK, your existing distance factor can be
essentially used as the extinction factor as long
as we are observing from a much greater distance.

It can. ..or you can set eccentricity at 0.01

No, set it to 2.3*10^-7 if anything, but you
don't need an explicit extinction term. Just
treat your program as an observer at infinity
and distance is the characteristic extinction
length.

Yes I can do that.
I only introduced the 'extinction' facility in order to try to obtain a value
for its rate.

Like I said, all I need is period, distance and a value for the maximum
radial
velocity.

Like I said, what you have is maximum Doppler shift.

No problem.

Indeed, but you need to fix the bug in the
software to convert from the shift to the
speed correctly.

George, this is a circular orbit and there is no difference between my and your
value of maximum velocity. I have tried to explain that extinction will not
affect measured doppler and its interpretation.


The red curve for the apparent speed. If you enter
27km/s the red curve should show that deviation
above and below the white axis. It would help if
you added a vertical scale or we cannot confirm
that. I'm presuming the value in the table on the
left called "Max. Vel." is your assumption for the
actual speed which you entered rather than the
highest point on the red curve.

The velocity curves are set to always have the same size on the screen. The
scale is linear and yes, the maximum is that shown in the velocity box. Ity
should be the same fro both red and blue curves.

No, it should be 0.00009c for the blue curve
at 8 light years and 1.0c for the red curve.
The 'wavelength' at that distance is zero.

George, I don't think we're taking about the same things here.
The blue curve is the true radial velocity curve towards the observer.
The red curve is generated in this way:

For the purpose of counting the arrival of pulses, the orbit period is divided
into 500 divisions, which form the elements of an array. The program adds all
the pulses that arrive in that division to make up the value of that array
element. It also follows each pulse individually so that it records the speed
at which the pulse left the source barycentre. It averages the velocities of
all the pulse that are placed into each array element.

Introducing extinction doesn't really change anything.

I have realised though that when using ellitical orbits I have to compensate
for Yaw angle because the maximum observed velocity is not necessarily the
velocity at periastron.

That could be the cause of your extra phase
change.

It shouldn't make much difference at low eccentricities and doesn't affect
brightness curve shape anyway. ..just the distance.


There is second
order term involving the 'rate of change of acceleration'. You have
omitted it.

I don't believe there is such a term but that's why
I want to do the short distance test first.

No, I was wrong there, although not entirely. The main reason the point moves
is due solely to the difference in emission times. For short distances, a half
period is quite significant.

Getting the correct location for the maximum speed
will matter too, but for our circular orbit it
shouldn't matter.

Anyway, bottom line at the moment is that you are
not calculating the apparent velocity correctly
from the pulse period so let's get that fixed
before worrying about the effects of eccentricity.

George you have it all back to front.

I don't want to calculate the velocity. I want to read about it in a table or
graph.
Can you provide that info for me?


George

On Feb 19, 2:56 pm, HW@....(Henri Wilson) wrote:

[snip all]


I don't want to calculate the velocity. I want to read about it in a table or
graph.
Can you provide that info for me?

Why should he do your research for you?




George

On 19 Feb, 23:56, HW@....(Henri Wilson) wrote:
On 19 Feb 2007 00:41:06 -0800, "George Dishman" wrote:
On 19 Feb, 04:44, HW@....(Henri Wilson) wrote:
On Mon, 19 Feb 2007 00:36:42 -0000, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
.. .
On Sun, 18 Feb 2007 10:59:26 -0000, "George Dishman"
But you cannot ever get that because the variable
speed messes up the Doppler equation. As with any
modelling technique, you put in your initial guess
of the actual parameters, the program caclulates
the observed signals and then you iterate until
the predicted observables match that actuals.

Ah, but I only need a value for the MAXIMUM orbital speed.

Ah, but you cannot know that, all you know is the
maximum Doppler shift.

That's all I need.

Yes but you have to process it appropriately. Your
program is not doing that at present.

It's near enough to do what I want at present..

No, it is wrong by a factor of 11000 at 8 light years.
Of course that's only a test but the number is going
to be badly wrong at any range of interest.

.. although I will have to take
Yaw angle into acount eventually..

Does that matter at the moment for a circular
orbit?

All I am doing now is matching curves. The value of (distance x max velocity)
is rather arbitrary because I dont really know the unification distance and it
is not easy to obtain velocity diagrams.

The BaTh and SR
doppler equations are effectively the same.

No they aren't, that's the whole point. Look at the
bottom of your reply where you agree the _apparent_
speed should reach c at the critical distance!

Yes.... but during extinction, the wavelength contracts or expands, so as to
still maintain the correct details of source velocity.

No, the speed matching causes the 'wavelength',
which in this case is the distance between pulses,
to eventually settle down to a constant value but
it will not be the original.

Not according to me.

They do according to the theory, you don't have
a choice.

The final distance between adjacent pulses will vary according to their initial
velocity relative to the barycentre. Some will move closer together, others
further apart.

They will also move closer and farther due to their
initially different speeds but that part will become
constant as the speeds equalise.

The extreme test
example here is for viewing at 8 light years with
negligible extinction, or equivalently at infinity
with an exponential extinction distance of 8 light
years, and the wavelength is zero. Your software
still gives v/c=0.00009 when it should be v/c=1.

George, unless I have access to a curve showing variation in pulse arrival
times I cannot help you much.

I've given you that repeatedly. The frequency varies by
30.5 mHz either side of 339 Hz.

Reading the papers about this pulsar is quite confusing for me

Indeed, but the basic information you need is trivial
for me. Some of the more specialised terms are less
clear but the basic orbit is simple.

because the
authors make such a big issue of Shapiro delay. (They even admit light is
slowed by gravity).

The Shapiro delay is what makes the system special.
It allows the inclination to be determined which
leads to highly accurate determination of a lot
of other parameters.

The BaTh interpretation would be quite different from
theirs.

It would, so stop looking for excuses and let's see what
your program says.

It can. ..or you can set eccentricity at 0.01

No, set it to 2.3*10^-7 if anything, but you
don't need an explicit extinction term. Just
treat your program as an observer at infinity
and distance is the characteristic extinction
length.

Yes I can do that.
I only introduced the 'extinction' facility in order to try to obtain a value
for its rate.

Essentially your distance parameter is already that.

Like I said, all I need is period, distance and a value for the maximum
radial velocity.

Like I said, what you have is maximum Doppler shift.

No problem.

Indeed, but you need to fix the bug in the
software to convert from the shift to the
speed correctly.

George, this is a circular orbit and there is no difference between my and your
value of maximum velocity. I have tried to explain that extinction will not
affect measured doppler and its interpretation.

Extinction in itself wouldn't but the initial speed
difference does affect the Dopppler. Faster pulses
catch up to slower ones for a while before extinction
matches their speeds. That means the pulses are closer
together giving the _false_ impression of a higher
speed. Your blue curve is the true speed, the red
curve should be the _apparent_ speed deduced from
the closed-up pulses. It should be _higher_ than the
blue curve.

The red curve for the apparent speed. If you enter
27km/s the red curve should show that deviation
above and below the white axis. It would help if
you added a vertical scale or we cannot confirm
that. I'm presuming the value in the table on the
left called "Max. Vel." is your assumption for the
actual speed which you entered rather than the
highest point on the red curve.

The velocity curves are set to always have the same size on the screen. The
scale is linear and yes, the maximum is that shown in the velocity box. Ity
should be the same fro both red and blue curves.

No, it should be 0.00009c for the blue curve
at 8 light years and 1.0c for the red curve.
The 'wavelength' at that distance is zero.

George, I don't think we're taking about the same things here.

I might occassionally get the red and blue transposed
but I don't think I have so far.

The blue curve is the true radial velocity curve towards the observer.

Yes.

The red curve is generated in this way:

For the purpose of counting the arrival of pulses, the orbit period is divided
into 500 divisions, which form the elements of an array. The program adds all
the pulses that arrive in that division to make up the value of that array
element. It also follows each pulse individually so that it records the speed
at which the pulse left the source barycentre. It averages the velocities of
all the pulse that are placed into each array element.

That will give the wrong answer. The pubilished velocity
data uses the conventional Doppler formula so the speed is

v = c * (df / f)

where df is the frequency shift

To find that, you can use the time between arrivals which
is just the period, or the inverse of the frequency.

Introducing extinction doesn't really change anything.

It stops the period changing after some distance, the
way you have it at the moment is fine. Just calculate
the Doppler shift from your pulse arrival times and you
will get the right answer.

I have realised though that when using ellitical orbits I have to compensate
for Yaw angle because the maximum observed velocity is not necessarily the
velocity at periastron.

That could be the cause of your extra phase
change.

It shouldn't make much difference at low eccentricities and doesn't affect
brightness curve shape anyway. ..just the distance.

It will have a small effect but for our circular
orbit, it is irrelevant. Can I ask that you lay
that aside on your to-do list until we finish
looking at J1909-3744.

There is second
order term involving the 'rate of change of acceleration'. You have
omitted it.

I don't believe there is such a term but that's why
I want to do the short distance test first.

No, I was wrong there, although not entirely. The main reason the point moves
is due solely to the difference in emission times. For short distances, a half
period is quite significant.

Getting the correct location for the maximum speed
will matter too, but for our circular orbit it
shouldn't matter.

Anyway, bottom line at the moment is that you are
not calculating the apparent velocity correctly
from the pulse period so let's get that fixed
before worrying about the effects of eccentricity.

George you have it all back to front.

I don't want to calculate the velocity. I want to read about it in a table or
graph.

Little children learn they don't always get what they
want. The published tables give the period and time
difference and I have done the calculation to turn that
into frequencies for you. All you need to do is fix the
bug in your program and then find the orbital parameters
and extinction that matches the observation.

Can you provide that info for me?

I have done many times Henry, stop trying to invent excuses.

George

On 20 Feb 2007 03:10:39 -0800, "George Dishman"
wrote:

On 19 Feb, 23:56, HW@....(Henri Wilson) wrote:
On 19 Feb 2007 00:41:06 -0800, "George Dishman" wrote:
On 19 Feb, 04:44, HW@....(Henri Wilson) wrote:
On Mon, 19 Feb 2007 00:36:42 -0000, "George Dishman"
wrote:
"Henri Wilson" HW@.... wrote in message
.. .
On Sun, 18 Feb 2007 10:59:26 -0000, "George Dishman"
But you cannot ever get that because the variable
speed messes up the Doppler equation. As with any
modelling technique, you put in your initial guess
of the actual parameters, the program caclulates
the observed signals and then you iterate until
the predicted observables match that actuals.

Ah, but I only need a value for the MAXIMUM orbital speed.

Ah, but you cannot know that, all you know is the
maximum Doppler shift.

That's all I need.

Yes but you have to process it appropriately. Your
program is not doing that at present.

It's near enough to do what I want at present..

No, it is wrong by a factor of 11000 at 8 light years.
Of course that's only a test but the number is going
to be badly wrong at any range of interest.

George, velocity and distance are conjugate.

If the velocity is 10% high then my distance will be10% low.
This is no big deal. I don't know where you are getting your figures.


.. although I will have to take
Yaw angle into acount eventually..

Does that matter at the moment for a circular
orbit?

No there is no error in a circular orbit.
However as I have shown, this is NOT a circular orbit according to BaTh. It has
an e ~ 0.06 with periastron furthest from observer.

The maximum OBSERVED radial velocity will differ only slighly from the maximum
PERIPHERAL velocity. However the phasing will be nearly 90 out!!!! So I'm going
to have to compensate for this when I compare phases.
I can do this fairly easily..and will do so soon.

I think this might explain why my curves for RT Aur were a fair way out in
phase.
Thakyou for your help George. You might have added another nail in Albert's
coffin.

All I am doing now is matching curves. The value of (distance x max velocity)
is rather arbitrary because I dont really know the unification distance and it
is not easy to obtain velocity diagrams.

The BaTh and SR
doppler equations are effectively the same.

No they aren't, that's the whole point. Look at the
bottom of your reply where you agree the _apparent_
speed should reach c at the critical distance!

Yes.... but during extinction, the wavelength contracts or expands, so as to
still maintain the correct details of source velocity.

No, the speed matching causes the 'wavelength',
which in this case is the distance between pulses,
to eventually settle down to a constant value but
it will not be the original.

Not according to me.

They do according to the theory, you don't have
a choice.

The final distance between adjacent pulses will vary according to their initial
velocity relative to the barycentre. Some will move closer together, others
further apart.

They will also move closer and farther due to their
initially different speeds but that part will become
constant as the speeds equalise.

Yes..but their spacing overall will retain a periodic bunching.
It is not CONSTANT all the way along.

The extreme test
example here is for viewing at 8 light years with
negligible extinction, or equivalently at infinity
with an exponential extinction distance of 8 light
years, and the wavelength is zero. Your software
still gives v/c=0.00009 when it should be v/c=1.

George, unless I have access to a curve showing variation in pulse arrival
times I cannot help you much.

I've given you that repeatedly. The frequency varies by
30.5 mHz either side of 339 Hz.

OK.


Reading the papers about this pulsar is quite confusing for me

Indeed, but the basic information you need is trivial
for me. Some of the more specialised terms are less
clear but the basic orbit is simple.

It turns out that this might not be true.

because the
authors make such a big issue of Shapiro delay. (They even admit light is
slowed by gravity).

The Shapiro delay is what makes the system special.
It allows the inclination to be determined which
leads to highly accurate determination of a lot
of other parameters.

Well the whole picture changes when you use c+v....as it does with most of
astrophysics. It becomes more simple and logical.

The BaTh interpretation would be quite different from
theirs.

It would, so stop looking for excuses and let's see what
your program says.

It is done.

It can. ..or you can set eccentricity at 0.01

No, set it to 2.3*10^-7 if anything, but you
don't need an explicit extinction term. Just
treat your program as an observer at infinity
and distance is the characteristic extinction
length.

Hahaha!
See, your claim that the orbit is circular is based on a perfectly sinelike
'red curve'. The BaTh shows that the OBSERVED sinewave velocity curve requires
an orbit with e ~ 0.6 or more depending on observer distance.

Yes I can do that.
I only introduced the 'extinction' facility in order to try to obtain a value
for its rate.

Essentially your distance parameter is already that.

Yes. For a mag change of 0.2, I get a distance of about 0.7 LY


Like I said, all I need is period, distance and a value for the maximum
radial velocity.

Like I said, what you have is maximum Doppler shift.

No problem.

Indeed, but you need to fix the bug in the
software to convert from the shift to the
speed correctly.

George, this is a circular orbit and there is no difference between my and your
value of maximum velocity. I have tried to explain that extinction will not
affect measured doppler and its interpretation.

Extinction in itself wouldn't but the initial speed
difference does affect the Dopppler. Faster pulses
catch up to slower ones for a while before extinction
matches their speeds. That means the pulses are closer
together giving the _false_ impression of a higher
speed. Your blue curve is the true speed, the red
curve should be the _apparent_ speed deduced from
the closed-up pulses. It should be _higher_ than the
blue curve.

No. The program averages the ORIGINAL pulse speeds that arrive in set time
intervals. It should oscillate between 'higher' and 'lower'.

The red curve for the apparent speed. If you enter
27km/s the red curve should show that deviation
above and below the white axis. It would help if
you added a vertical scale or we cannot confirm
that. I'm presuming the value in the table on the
left called "Max. Vel." is your assumption for the
actual speed which you entered rather than the
highest point on the red curve.

The velocity curves are set to always have the same size on the screen. The
scale is linear and yes, the maximum is that shown in the velocity box. Ity
should be the same fro both red and blue curves.

No, it should be 0.00009c for the blue curve
at 8 light years and 1.0c for the red curve.
The 'wavelength' at that distance is zero.

George, I don't think we're taking about the same things here.

I might occassionally get the red and blue transposed
but I don't think I have so far.

The blue curve is the true radial velocity curve towards the observer.

Yes.

The red curve is generated in this way:

For the purpose of counting the arrival of pulses, the orbit period is divided
into 500 divisions, which form the elements of an array. The program adds all
the pulses that arrive in that division to make up the value of that array
element. It also follows each pulse individually so that it records the speed
at which the pulse left the source barycentre. It averages the velocities of
all the pulse that are placed into each array element.

That will give the wrong answer. The pubilished velocity
data uses the conventional Doppler formula so the speed is

v = c * (df / f)

where df is the frequency shift

To find that, you can use the time between arrivals which
is just the period, or the inverse of the frequency.

But you are using constant 'c'!!!. I'm using c+v...Naturally I will get a
different answer.

Introducing extinction doesn't really change anything.

It stops the period changing after some distance, the
way you have it at the moment is fine.

That's not good way to put it.
Nothing happens to the period no matter how extinction operates.

Just calculate
the Doppler shift from your pulse arrival times and you
will get the right answer.

Just stick c+v into your formula George and YOU will get right answer.
...Oh, and you might need a computer program to do it because v varies with
time.

I have realised though that when using ellitical orbits I have to compensate
for Yaw angle because the maximum observed velocity is not necessarily the
velocity at periastron.

That could be the cause of your extra phase
change.

It shouldn't make much difference at low eccentricities and doesn't affect
brightness curve shape anyway. ..just the distance.

It will have a small effect but for our circular
orbit, it is irrelevant. Can I ask that you lay
that aside on your to-do list until we finish
looking at J1909-3744.

It is done.
It supports the BaTh observation that extinction distance is inversely velocity
dependent...which is odd when you think about it.

There is second
order term involving the 'rate of change of acceleration'. You have
omitted it.

I don't believe there is such a term but that's why
I want to do the short distance test first.

No, I was wrong there, although not entirely. The main reason the point moves
is due solely to the difference in emission times. For short distances, a half
period is quite significant.

Getting the correct location for the maximum speed
will matter too, but for our circular orbit it
shouldn't matter.

Anyway, bottom line at the moment is that you are
not calculating the apparent velocity correctly
from the pulse period so let's get that fixed
before worrying about the effects of eccentricity.

George you have it all back to front.

I don't want to calculate the velocity. I want to read about it in a table or
graph.

Little children learn they don't always get what they
want. The published tables give the period and time
difference and I have done the calculation to turn that
into frequencies for you. All you need to do is fix the
bug in your program and then find the orbital parameters
and extinction that matches the observation.

you are using constant c.
I'm using c+v.

Can you provide that info for me?

I have done many times Henry, stop trying to invent excuses.

George

"Henri Wilson" HW@.... wrote in message
...
On 20 Feb 2007 03:10:39 -0800, "George Dishman"
wrote:

On 19 Feb, 23:56, HW@....(Henri Wilson) wrote:
On 19 Feb 2007 00:41:06 -0800, "George Dishman"
wrote:
On 19 Feb, 04:44, HW@....(Henri Wilson) wrote:
On Mon, 19 Feb 2007 00:36:42 -0000, "George Dishman"

wrote:
"Henri Wilson" HW@.... wrote in message
.. .
On Sun, 18 Feb 2007 10:59:26 -0000, "George Dishman"
But you cannot ever get that because the variable
speed messes up the Doppler equation. As with any
modelling technique, you put in your initial guess
of the actual parameters, the program caclulates
the observed signals and then you iterate until
the predicted observables match that actuals.

Ah, but I only need a value for the MAXIMUM orbital speed.

Ah, but you cannot know that, all you know is the
maximum Doppler shift.

That's all I need.

Yes but you have to process it appropriately. Your
program is not doing that at present.

It's near enough to do what I want at present..

No, it is wrong by a factor of 11000 at 8 light years.
Of course that's only a test but the number is going
to be badly wrong at any range of interest.

George, velocity and distance are conjugate.

If the velocity is 10% high then my distance will be10% low.
This is no big deal. I don't know where you are getting your figures.

I did explain Henry, at the critical distance the
gap between pulses is zero so your program should
report a value of c for the observed velocity curve
but the peak is the same height as the true value
which you entered as 0.0009. That's wrong by a
factor of 11000.

.. although I will have to take
Yaw angle into acount eventually..

Does that matter at the moment for a circular
orbit?

No there is no error in a circular orbit.
However as I have shown, this is NOT a circular orbit according to BaTh.
It has
an e ~ 0.06 with periastron furthest from observer.

The maximum OBSERVED radial velocity will differ only slighly from the
maximum
PERIPHERAL velocity. However the phasing will be nearly 90 out!!!! So I'm
going
to have to compensate for this when I compare phases.
I can do this fairly easily..and will do so soon.

OK.

I think this might explain why my curves for RT Aur were a fair way out in
phase.
Thakyou for your help George. You might have added another nail in
Albert's
coffin.

Not until you fix the velocity magnitude error :-)

....
The final distance between adjacent pulses will vary according to their
initial
velocity relative to the barycentre. Some will move closer together,
others
further apart.

They will also move closer and farther due to their
initially different speeds but that part will become
constant as the speeds equalise.

Yes..but their spacing overall will retain a periodic bunching.
It is not CONSTANT all the way along.

I think that's what I just said. It isn't constant
and reduces or grows until the speeds equalise
after which they remain unchanged regardless of
distance. Your method doesn't take the effect of
the initial speed difference into account. Your
trick of using the brightness curve instead in
your other mail is an effective workaround for
the moment though.

George, unless I have access to a curve showing variation in pulse
arrival
times I cannot help you much.

I've given you that repeatedly. The frequency varies by
30.5 mHz either side of 339 Hz.

OK.

Reading the papers about this pulsar is quite confusing for me

Indeed, but the basic information you need is trivial
for me. Some of the more specialised terms are less
clear but the basic orbit is simple.

It turns out that this might not be true.

Understood, what I mean is that it is simple to
understand the published basic orbital parameters
and reverse them back to find what was observed.
After that, you have to try to match the observation
with the Ritzian analysis and I fully expect your
orbital parameters to differ from those determined
by conventional means. In fact that's the point,
it is not a useful test if both theories give the
same results.

The Shapiro delay is what makes the system special.
It allows the inclination to be determined which
leads to highly accurate determination of a lot
of other parameters.

Well the whole picture changes when you use c+v....as it does with most of
astrophysics. It becomes more simple and logical.

We'll see :-)

The BaTh interpretation would be quite different from
theirs.

It would, so stop looking for excuses and let's see what
your program says.

It is done.

Your method was fine but you misread the number,
try again.

It can. ..or you can set eccentricity at 0.01

No, set it to 2.3*10^-7 if anything, but you
don't need an explicit extinction term. Just
treat your program as an observer at infinity
and distance is the characteristic extinction
length.

Hahaha!
See, your claim that the orbit is circular is based on a perfectly
sinelike
'red curve'. The BaTh shows that the OBSERVED sinewave velocity curve
requires
an orbit with e ~ 0.6 or more depending on observer distance.

Yes, that's the sort of difference I am expecting.
I assume your program deals with Kepler's second
law?

Yes I can do that.
I only introduced the 'extinction' facility in order to try to obtain a
value
for its rate.

Essentially your distance parameter is already that.

Yes. For a mag change of 0.2, I get a distance of about 0.7 LY

OK but the mag change is 0.0002, the frequency deviation
is mHz, not Hz.


George, this is a circular orbit and there is no difference between my
and your
value of maximum velocity. I have tried to explain that extinction will
not
affect measured doppler and its interpretation.

Extinction in itself wouldn't but the initial speed
difference does affect the Dopppler. Faster pulses
catch up to slower ones for a while before extinction
matches their speeds. That means the pulses are closer
together giving the _false_ impression of a higher
speed. Your blue curve is the true speed, the red
curve should be the _apparent_ speed deduced from
the closed-up pulses. It should be _higher_ than the
blue curve.

No. The program averages the ORIGINAL pulse speeds that arrive in set time
intervals.

Yes, that's the error. The _published_ speed curve
will be based on the inverse period, the time
between pulse arrivals so that's what you need
to put into the simulation to make the curve
comparable.

The red curve is generated in this way:

For the purpose of counting the arrival of pulses, the orbit period is
divided
into 500 divisions, which form the elements of an array. The program
adds all
the pulses that arrive in that division to make up the value of that
array
element. It also follows each pulse individually so that it records the
speed
at which the pulse left the source barycentre. It averages the
velocities of
all the pulse that are placed into each array element.

That will give the wrong answer. The pubilished velocity
data uses the conventional Doppler formula so the speed is

v = c * (df / f)

where df is the frequency shift

To find that, you can use the time between arrivals which
is just the period, or the inverse of the frequency.

But you are using constant 'c'!!!. I'm using c+v...Naturally I will get a
different answer.

I only use constant c to reverse the published orbit
to get the observations. The orbit is determined
that way so i have to use that to reverse the process.
Once we know what was observed, then I expect your
program to use c+v to calculate the arrival times
and then the standard Doppler effect equation to get
what would be a published curve from that.

Introducing extinction doesn't really change anything.

It stops the period changing after some distance, the
way you have it at the moment is fine.

That's not good way to put it.
Nothing happens to the period no matter how extinction operates.

We seem to be at cross purposes. Without the extinction,
the period would continue to change forever as the fast
pulses catch up to and move past the slow ones. Extinction
slows and eventually stops that effect but the catch-up
that has already happened is not removed. Don't you have
an animation of this?

Just calculate
the Doppler shift from your pulse arrival times and you
will get the right answer.

Just stick c+v into your formula George and YOU will get right answer.

Published curves don't use c+v Henry. If we are to
compare your prediction with velocity curves, you
need to convert them from the pulse period in the
same way that everyone else does.

..Oh, and you might need a computer program to do it because v varies with
time.

The Doppler equation uised by astronomers doesn't and
that's all you are replicating.

It shouldn't make much difference at low eccentricities and doesn't
affect
brightness curve shape anyway. ..just the distance.

It will have a small effect but for our circular
orbit, it is irrelevant. Can I ask that you lay
that aside on your to-do list until we finish
looking at J1909-3744.

It is done.
It supports the BaTh observation that extinction distance is inversely
velocity
dependent...which is odd when you think about it.

Impossible actually, it can depend on the nature
of the medium but not the orbit.

I don't want to calculate the velocity. I want to read about it in a
table or
graph.

Little children learn they don't always get what they
want. The published tables give the period and time
difference and I have done the calculation to turn that
into frequencies for you. All you need to do is fix the
bug in your program and then find the orbital parameters
and extinction that matches the observation.

you are using constant c.

To get the frequency, yes.

I'm using c+v.

Yes, for the next stage.

George

On Wed, 21 Feb 2007 18:35:50 -0000, "George Dishman"
wrote:


"Henri Wilson" HW@.... wrote in message
.. .
On 20 Feb 2007 03:10:39 -0800, "George Dishman"
wrote:



It's near enough to do what I want at present..

No, it is wrong by a factor of 11000 at 8 light years.
Of course that's only a test but the number is going
to be badly wrong at any range of interest.

George, velocity and distance are conjugate.

If the velocity is 10% high then my distance will be10% low.
This is no big deal. I don't know where you are getting your figures.

I did explain Henry, at the critical distance the
gap between pulses is zero so your program should
report a value of c for the observed velocity curve
but the peak is the same height as the true value
which you entered as 0.0009. That's wrong by a
factor of 11000.

I think I know what you are trying to say here George.

At the critical distance, SOME pulses arrive together not ALL of them. that is
because a cincave section of the orbit is such tat a large group of pulses will
arrive at a distant point over a very short time interval.
They will have started out with a range of speeds; that's why some catch up
with the others.

After extinction, they will all be traveling at about c wrt the source BUT
their wavelengths will have changed so that their source speeds will still
appear to be the correct ones, when measured with a grating at the observer
distance..

So my graph shows the 'no extinction' case...because I say extinction makes no
difference to the measured doppler shift.

.. although I will have to take
Yaw angle into acount eventually..

Does that matter at the moment for a circular
orbit?

No there is no error in a circular orbit.
However as I have shown, this is NOT a circular orbit according to BaTh.
It has
an e ~ 0.06 with periastron furthest from observer.

The maximum OBSERVED radial velocity will differ only slighly from the
maximum
PERIPHERAL velocity. However the phasing will be nearly 90 out!!!! So I'm
going
to have to compensate for this when I compare phases.
I can do this fairly easily..and will do so soon.

OK.

I said the wrong thing there. The phasing is correct as shown on my program.
The maximum velocity will be slightly out though because the OBSERVED maximum
will not be the peripheral maximum unless my Yaw angle is exactly zero.
I'm still working on this. It isn't a serious flaw.
Incidentally, I have further modified my program so the red and blue curves can
be vertically separated for clarity.


I think this might explain why my curves for RT Aur were a fair way out in
phase.
Thakyou for your help George. You might have added another nail in
Albert's
coffin.

Not until you fix the velocity magnitude error :-)

There is no significant error...none at all for circular orbits.
Please explain why you think there is an error..

The final distance between adjacent pulses will vary according to their
initial
velocity relative to the barycentre. Some will move closer together,
others
further apart.

They will also move closer and farther due to their
initially different speeds but that part will become
constant as the speeds equalise.

Yes..but their spacing overall will retain a periodic bunching.
It is not CONSTANT all the way along.

I think that's what I just said. It isn't constant
and reduces or grows until the speeds equalise
after which they remain unchanged regardless of
distance.

OK we agree on that.

Your method doesn't take the effect of
the initial speed difference into account.

Don't be silly George, Of course it does. That's the whole basis of the
calculation.
The radial speed at each point around the orbit is c + vcos(A)

Your
trick of using the brightness curve instead in
your other mail is an effective workaround for
the moment though.

George, unless I have access to a curve showing variation in pulse
arrival
times I cannot help you much.

I've given you that repeatedly. The frequency varies by
30.5 mHz either side of 339 Hz.

OK.

Reading the papers about this pulsar is quite confusing for me

Indeed, but the basic information you need is trivial
for me. Some of the more specialised terms are less
clear but the basic orbit is simple.

It turns out that this might not be true.

Understood, what I mean is that it is simple to
understand the published basic orbital parameters
and reverse them back to find what was observed.
After that, you have to try to match the observation
with the Ritzian analysis and I fully expect your
orbital parameters to differ from those determined
by conventional means. In fact that's the point,
it is not a useful test if both theories give the
same results.

Interestingly, according to BaTh, the observed velocity curve at distance from
a star in perfectly circular orbit will be skewed. The amount of skew will
depend on distance.
The orbit that WILL produce a perfect sinewave velocity curve will have an
eccentricity up to about 0.2 and periastron about nearest to us.
For instance, the settings e=0.1, yaw = -90, distance = 70, period 1 yr,
velocity 0.0005 produces a near sinewave at observer, whereas the curve at
source is quite skewed.


The Shapiro delay is what makes the system special.
It allows the inclination to be determined which
leads to highly accurate determination of a lot
of other parameters.

Well the whole picture changes when you use c+v....as it does with most of
astrophysics. It becomes more simple and logical.

We'll see :-)

The BaTh interpretation would be quite different from
theirs.

It would, so stop looking for excuses and let's see what
your program says.

It is done.

Your method was fine but you misread the number,
try again.

Yes.

It can. ..or you can set eccentricity at 0.01

No, set it to 2.3*10^-7 if anything, but you
don't need an explicit extinction term. Just
treat your program as an observer at infinity
and distance is the characteristic extinction
length.

Hahaha!
See, your claim that the orbit is circular is based on a perfectly
sinelike
'red curve'. The BaTh shows that the OBSERVED sinewave velocity curve
requires
an orbit with e ~ 0.6 or more depending on observer distance.

Yes, that's the sort of difference I am expecting.
I assume your program deals with Kepler's second
law?

No, it uses Newton's equation and actually verifies Kepler's laws.

Yes I can do that.
I only introduced the 'extinction' facility in order to try to obtain a
value
for its rate.

Essentially your distance parameter is already that.

Yes. For a mag change of 0.2, I get a distance of about 0.7 LY

OK but the mag change is 0.0002, the frequency deviation
is mHz, not Hz.

Yes OK , the extinction distance is 1 Lday.
Not impossible, it is a neutron star, after all.




No. The program averages the ORIGINAL pulse speeds that arrive in set time
intervals.

Yes, that's the error. The _published_ speed curve
will be based on the inverse period, the time
between pulse arrivals so that's what you need
to put into the simulation to make the curve
comparable.

George, the velocity will range from ~27000 +/-~0.01% m/s
Do you agree?

The red curve is generated in this way:

For the purpose of counting the arrival of pulses, the orbit period is
divided
into 500 divisions, which form the elements of an array. The program
adds all
the pulses that arrive in that division to make up the value of that
array
element. It also follows each pulse individually so that it records the
speed
at which the pulse left the source barycentre. It averages the
velocities of
all the pulse that are placed into each array element.

That will give the wrong answer. The pubilished velocity
data uses the conventional Doppler formula so the speed is

v = c * (df / f)

where df is the frequency shift

To find that, you can use the time between arrivals which
is just the period, or the inverse of the frequency.

But you are using constant 'c'!!!. I'm using c+v...Naturally I will get a
different answer.

I only use constant c to reverse the published orbit
to get the observations. The orbit is determined
that way so i have to use that to reverse the process.
Once we know what was observed, then I expect your
program to use c+v to calculate the arrival times
and then the standard Doppler effect equation to get
what would be a published curve from that.

Do you agree with the above velocity curve?


Introducing extinction doesn't really change anything.

It stops the period changing after some distance, the
way you have it at the moment is fine.

That's not good way to put it.
Nothing happens to the period no matter how extinction operates.

We seem to be at cross purposes.

We often are.

Without the extinction,
the period would continue to change forever as the fast
pulses catch up to and move past the slow ones. Extinction
slows and eventually stops that effect but the catch-up
that has already happened is not removed. Don't you have
an animation of this?

Beyond the critical distance, multiple images form and the brightness curve
goes haywire. It can appear like a high frequency variation but is hard to
analyse..
Below the critical distance the period of the brightness curve is not affected
by the degree of extinction.


Just calculate
the Doppler shift from your pulse arrival times and you
will get the right answer.

Just stick c+v into your formula George and YOU will get right answer.

Published curves don't use c+v Henry. If we are to
compare your prediction with velocity curves, you
need to convert them from the pulse period in the
same way that everyone else does.

It's a straight out doppler conversion, surely.


..Oh, and you might need a computer program to do it because v varies with
time.

The Doppler equation uised by astronomers doesn't and
that's all you are replicating.

It shouldn't make much difference at low eccentricities and doesn't
affect
brightness curve shape anyway. ..just the distance.

It will have a small effect but for our circular
orbit, it is irrelevant. Can I ask that you lay
that aside on your to-do list until we finish
looking at J1909-3744.

It is done.
It supports the BaTh observation that extinction distance is inversely
velocity
dependent...which is odd when you think about it.

Impossible actually, it can depend on the nature
of the medium but not the orbit.

I know.
It might also depend on the mass of the star...which is directly related to the
orbit period.

I don't want to calculate the velocity. I want to read about it in a
table or
graph.

Little children learn they don't always get what they
want. The published tables give the period and time
difference and I have done the calculation to turn that
into frequencies for you. All you need to do is fix the
bug in your program and then find the orbital parameters
and extinction that matches the observation.

you are using constant c.

To get the frequency, yes.

I'm using c+v.

Yes, for the next stage.

George

Most of our views on this are now in accord, I only
address the speed issue here and maybe pick up some
other minor points separately later.

First I'll take one paragraph from later on;


Your method doesn't take the effect of
the initial speed difference into account.

Don't be silly George, Of course it does. That's the whole basis of the
calculation.
The radial speed at each point around the orbit is c + vcos(A)

I said before you could treat cos(A) as being always 1.
I was thinking there of the angle between the line of
sight and the line between the barycentres. Your angle
is between to have used the line of sight and the
velocity which of course is essential but if you make
it the angle between the velocity and a line joining
the barycentres then there will be a negligible error,
essentially the view from infinity, and it will work
at zero distance to allow comparison with the conventional
model.

Thanks to Jeff Root for pointing out my misunderstanding
of your definition.


"Henri Wilson" HW@.... wrote in message
...
On Wed, 21 Feb 2007 18:35:50 -0000, "George Dishman"
wrote:
....
I did explain Henry, at the critical distance the
gap between pulses is zero so your program should
report a value of c for the observed velocity curve
but the peak is the same height as the true value
which you entered as 0.0009. That's wrong by a
factor of 11000.

I think I know what you are trying to say here George.

At the critical distance, SOME pulses arrive together not ALL of them.
that is
because a cincave section of the orbit is such tat a large group of pulses
will
arrive at a distant point over a very short time interval.
They will have started out with a range of speeds; that's why some catch
up
with the others.

Yes.

After extinction, they will all be traveling at about c wrt the source BUT
their wavelengths will have changed so that their source speeds will still
appear to be the correct ones, when measured with a grating at the
observer
distance..

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.

So my graph shows the 'no extinction' case...because I say extinction
makes no
difference to the measured doppler shift.
....
There is no significant error...none at all for circular orbits.
Please explain why you think there is an error..
....
Yes, that's the error. The _published_ speed curve
will be based on the inverse period, the time
between pulse arrivals so that's what you need
to put into the simulation to make the curve
comparable.

George, the velocity will range from ~27000 +/-~0.01% m/s
Do you agree?

I am saying that, for any significant extinction
distance, the red line should have a greater
variation than the blue line. To find the true
speed, you adjust the velocity parameter until the
red line matches the published velocity curve. What
we need to sort out is why I think the red should
be higher than the blue.

They will also move closer and farther due to their
initially different speeds but that part will become
constant as the speeds equalise.

Yes..but their spacing overall will retain a periodic bunching.
It is not CONSTANT all the way along.

I think that's what I just said. It isn't constant
and reduces or grows until the speeds equalise
after which they remain unchanged regardless of
distance.

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. 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).

It is only that final pulse separation that we can
measure and which has been used to calculate the
27km/s value, and of course the published values assume
invariant speed. That means that if you want to compare
your program's output, specifically the blue line, with
published curves, you need to convert the received PRF
to a velocity _as_if_ the speed were always c, not
because of the physics but (if you like to think of it
this way) because that is the publishing convention.

In a nutshell, the shortened inter-pulse gap due to c+v
catch-up tricks us into thinking the orbital velocity
is higher than it really is. The red curve is the real
value and the blue curve is the "constant c" value
inferred from that shortened gap between pulses.

Does that make it clearer Henry?

If you follow that, you should appreciate that instead
of saying the extinction is 6 light hours, you could
keep your 0.7 light year figure but drop the orbital
speed to 27 m/s. Of course that's not tenable for a
variety of other reasons but it might illustrate the
point, almost all the apparent "Doppler" shift would
actually be due to the pulse catch-up effect.

For those parameters, the red curve would be 27983 m/s
but the blue curve would be only 27 m/s, and because
most of the red curve is due to the acceleration at
the time of emission, there would be a 90 degree phase
difference.

George

"George Dishman" wrote in news:erjqgg$hvk$1
@news.freedom2surf.net:

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.



Should not the points of maximun relative velocity for energy from the
neutron star should be when the neutron star is along a line perpendicular
to the line of sight AND passing through the center of the dwarf?

In other words, when the neutron star is furthest from passing behind or in
front of the dwarf (as seen from earth).

Those are the times when the neutron star is going away from us or
approaching us at maximum velocity.

You said:

E------------------D N (where N is slightly above or below the line of
sight from earth through D)

I say:
N+
|
E------------------D
or |
N-


Or did I misunderstand what you said?



--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

On Thu, 22 Feb 2007 10:17:35 -0000, "George Dishman"
wrote:


Most of our views on this are now in accord, I only
address the speed issue here and maybe pick up some
other minor points separately later.

First I'll take one paragraph from later on;


Your method doesn't take the effect of
the initial speed difference into account.

Don't be silly George, Of course it does. That's the whole basis of the
calculation.
The radial speed at each point around the orbit is c + vcos(A)

I said before you could treat cos(A) as being always 1.

A is a function of time George. I pointed that out way back.

I was thinking there of the angle between the line of
sight and the line between the barycentres. Your angle
is between to have used the line of sight and the
velocity which of course is essential but if you make
it the angle between the velocity and a line joining
the barycentres then there will be a negligible error,
essentially the view from infinity, and it will work
at zero distance to allow comparison with the conventional
model.

Thanks to Jeff Root for pointing out my misunderstanding
of your definition.

You are still completely misunderstanding the whole thing.


"Henri Wilson" HW@.... wrote in message
.. .
On Wed, 21 Feb 2007 18:35:50 -0000, "George Dishman"
wrote:
...
I did explain Henry, at the critical distance the
gap between pulses is zero so your program should
report a value of c for the observed velocity curve
but the peak is the same height as the true value
which you entered as 0.0009. That's wrong by a
factor of 11000.

I think I know what you are trying to say here George.

At the critical distance, SOME pulses arrive together not ALL of them.
that is
because a cincave section of the orbit is such tat a large group of pulses
will
arrive at a distant point over a very short time interval.
They will have started out with a range of speeds; that's why some catch
up
with the others.

Yes.

After extinction, they will all be traveling at about c wrt the source BUT
their wavelengths will have changed so that their source speeds will still
appear to be the correct ones, when measured with a grating at the
observer
distance..

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'. BaTh bunching is virtually the same.

So my graph shows the 'no extinction' case...because I say extinction
makes no
difference to the measured doppler shift.
...
There is no significant error...none at all for circular orbits.
Please explain why you think there is an error..
...
Yes, that's the error. The _published_ speed curve
will be based on the inverse period, the time
between pulse arrivals so that's what you need
to put into the simulation to make the curve
comparable.

George, the velocity will range from ~27000 +/-~0.01% m/s
Do you agree?

I am saying that, for any significant extinction
distance, the red line should have a greater
variation than the blue line. To find the true
speed, you adjust the velocity parameter until the
red line matches the published velocity curve. What
we need to sort out is why I think the red should
be higher than the blue.

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.

They will also move closer and farther due to their
initially different speeds but that part will become
constant as the speeds equalise.

Yes..but their spacing overall will retain a periodic bunching.
It is not CONSTANT all the way along.

I think that's what I just said. It isn't constant
and reduces or grows until the speeds equalise
after which they remain unchanged regardless of
distance.

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.

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

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.

It is only that final pulse separation that we can
measure and which has been used to calculate the
27km/s value, and of course the published values assume
invariant speed. That means that if you want to compare
your program's output, specifically the blue line, with
published curves, you need to convert the received PRF
to a velocity _as_if_ the speed were always c, not
because of the physics but (if you like to think of it
this way) because that is the publishing convention.

In a nutshell, the shortened inter-pulse gap due to c+v
catch-up tricks us into thinking the orbital velocity
is higher than it really is. The red curve is the real
value and the blue curve is the "constant c" value
inferred from that shortened gap between pulses.

No you've got it all wrong George.
The BLUE curve is the actual one. (It will also be the one generated using pure
doppler very near the source).
The maximum ampitude of the red curve (from the doppler shifts the observer
measures) can never be higher than c+v.


Does that make it clearer Henry?

If you follow that, you should appreciate that instead
of saying the extinction is 6 light hours, you could
keep your 0.7 light year figure but drop the orbital
speed to 27 m/s. Of course that's not tenable for a
variety of other reasons but it might illustrate the
point, almost all the apparent "Doppler" shift would
actually be due to the pulse catch-up effect.

For those parameters, the red curve would be 27983 m/s
but the blue curve would be only 27 m/s, and because
most of the red curve is due to the acceleration at
the time of emission, there would be a 90 degree phase
difference.

You are not taking into account the effect of the delay in emission time. That
affects the spacing. It results in doppler wavelength shift for the constant c
model but not the BaTh one. For the latter, a doppler shift occurs during speed
change.

I think you should write a computer program to do all this George, instead of
trying to analyse the thing the way you are doing it.

It took me six years part-time to get it right....good luck.

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.

"Henri Wilson" HW@.... wrote in message
...
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