Why are the 'Fixed Stars' so FIXED?

On Feb 28, 3:21 am, HW@....(Henri Wilson) wrote:
On 27 Feb 2007 16:01:11 -0800, "PD" wrote:

On Feb 27, 5:23 pm, HW@....(Henri Wilson) wrote:
On 27 Feb 2007 07:11:36 -0800, "PD" wrote:

Yes. A frame dependent one...but you don't know what that means Draper.

Sure I do, and on this small point we're in agreement.
So tell me, what makes momentum a physical entity and spacetime not?

Momentum has physical rammifications. Spacetime is just a method of viewing a
physical situation.

Which "physical rammifications" do you have in mind for momentum.
Do you think that 3D space has "physical rammifications"? Does
Euclidean geometry count as a "physical rammification"?

No

So what physical "rammifications" do you have in mind for momentum?

You don't consider the measurable distance between here and the
library being invariant, independent of the orientiation of the
coordinate system, to be a physical "rammification"?


Oh crap Draper.
You blokes like to rave about this 'spacetime' when you haven't a clue what you
are even talking about.

Try plotting the snapping of fingers in a 4D representation Draper.

Sure. It's a little blot on a 4D space, kind of like the period at the
end of this sentence.

Hahahojhohoh!

Ah, I see this is news to you. Whenever someone tells you something
you didn't know, your first reaction is to laugh. I can see why you
did so well in school.


Better still, try something simple like a ball falling to ground. You can plot
that in 2D.

That's not a spacetime event, Henri. That's a sequence of spacetime
events. Now, the ball *landing* on the ground, that's a spacetime
event.

Hahahahwhwhahwahwahawhawhohohohohohoh!

More news, I see.


Then tell me in which school, and under what professor, using which
textbook, you got the idea that a frame is everything at rest with
respect to a defined point.

Everything at rest wrt a particular point or frame is in that frame and can
define that frame.
Other objects can move wrt that frame but are not in it.

And that's ridiculous, Henri.

See? You can't answer a simple question. I asked you where you got
this notion, and all you can do is repeat it.
HW: "2+2=7.43"
PD: "Why Henri, wherever did you get that idea?"
HW: "Don't be an idiot, PD. 2+2=7.43"

Draper, most people here - excluding the ratpack - show a few signs of
intelligence. Why can't you?


Ah, so because you say I should show a few signs of intelligence, that
means I should take your word that 2+2=7.43?


Now once again: Where did you get the idea that a frame is everything
that is at rest with respect to a defined point?

You really can't answer a simple question, Henri? This isn't about me
going to school, it's about where YOU got this idea.

stop raving Draper. You are a waste of time...

Every time I ask you a question you don't want to answer (or you can't
remember what the answer is), you say it's raving.

Every time you say something stupid and I point it out to you, you say
that any "real physicist" understands what you are talking about and
agrees with it, and then when I ask you what "real physicist" that is,
you suddenly say I am raving. It's like a little pattern with you. I
can ring a little bell and you'll salivate.

I know you're just trying to waste my time Draper.

'If you can't beat 'em, at least slow them down"

Nah, just pointing out when you say something stupid, Henri. That
normally *does* slow people down. However, in your case, you proceed
full speed ahead. Explains a lot.


A reference frame is simply something that can be used to compare velocities.

Really? How can a reference frame be something that can be used to
compare velocities, if the only things that are in the frame are
things that are mutually at rest?

Or are you saying that the only way to compare the velocity of a stop
sign and a truck is to find the two reference frames in which each of
these things is at rest and then compare the two reference frames?
Sort of a "Have your people talk to my people" kind of thing?

Gord, you really are hopeless Draper.



Are you really this dense?

And what "real physicist" says that a reference frame is defined as
everything that is at rest with respect to a defined point? And which
"real physicist" says that a reference frame is simply something that
can be used to compare velocities? You still haven't answered either
of these questions.

Why don't you ask captain Roberts.

Why? I asked you about YOUR idea. Now you deflect. Avoiding, Henri?


IT'S A BLOODY REFERENCE FOR VELOCITIES.
EVERYTHING THAT IS MUTUALLY AT REST IS IN THE SAME FRAME.

As well as everything that is not mutually at rest -- all in the same
frame. Do you disagree with that?

You are a moron Draper. Are you thinking of an ant walking across a framed
picture?

Objects that are moving wrt a frame ARE NOT in that frame. The ant is NOT in
the frame of the picture.

Of course the ant is not in the frame of the picture. The frame of a
picture forms a boundary around a picture. What does this have to do
with a reference frame, Henri? Were you thinking that a reference
frame is a box around a collection of objects?

No but you apparently are.

I didn't bring up ants and a picture frame. You did.
I didn't say a reference frame is everything at rest with respect to a
defined point. You did.

I said that everything that is moving with respect to a defined point
is *also* in that frame. You apparently don't think so. I've asked you
where on earth you got that idea. You've yet to answer.

Is life one big game of dodge-ball for you, Henri?

PD

On 28 Feb 2007 06:05:46 -0800, "George Dishman"
wrote:

On 27 Feb, 22:11, HW@....(Henri Wilson) wrote:
On Tue, 27 Feb 2007 09:22:01 -0000, "George Dishman"


f'/f = c/(c-v)

or using the time between arrivals and turning it round
to find v:

v = c(1 - t'/t)

Distance does not appear in this equation.


I am making an assumption that your current code is correct
and includes all the effects in the way it calculates the
pulse arrival times.

No, there are many complications.
I'm quite confident my program is correct.

If your program is correct, so will the result
found from it.

This is how I will have to approach it.

My program assumes that identical pulses are emitted at regular intervals from
some 30000 points around the orbit. (the pulsar does much the same) The true
radial velocities towards the observer are known and are stored in an array.
The emission 'lag' between consecutive pulses is period/30000. ...that provides
the value of t.

Yes, so far so good.

The program calculates the maximum and minimum travel times over the observer
distance of the pulses emitted in one cycle . (I actually use three period
cycles to avoid end effects but we will only talk about 1 period here.)
The max and min are divided into 167 equal time divisions, into which each
pulse is appropriately placed as it arrives..

"as it arrives" is the key phrase there. I am assuming you
take into account both the location of the source in its
orbit and the radial speed in order to calculate the time
taken. If you are ignoring the location and just dividing
the distance between the barycentres of the binary system
and the solar system by the c+v speed then you will have
another error that I wasn't previously aware of.

Both Androcles and I soon realised that it is not necessary to include the
Rsin(theta) term because it is always very small compared with relative
movement of pulses over many lightyears.
Ignore it George.

For large magnitude variations that would be true but
Cepheids variability ranges over roughly 0.6 to 2.0
mag which is quite small. At 0.6 mag, ignoring the
velocity part will give a phase error of around 40
degrees (mental arithmetic) so definitely cannot be
ignored.

...although, it might be significant for your pulsar.

It is significant for both stars and pulsars for a
brightness variation of less than about 3 to keep
the phase error below about 10 degrees.

We have been talking about different things here.


If 'n' pulses arrive in a particular time division at distance D, then
n/180 is
an indication of the bunching there.

Right, or say b = n/180 and you plot b as the green curve.

Yes.....well, I actually plot n with a scaling factor.

If you calculate v = c(1 - 1/b) then you get the "willusory"
radial speed so v = c(1 - 180/n). Just plot v as the red
curve and the job is done.

But I don't have to.

Yes you do, that's what is published and what you
have to compare against.

The program has already recorded the true radial velocities of all the pulses
that arrive in a certain time division. It takes the average and plots that.

I concede that when the number of pulses that arrive in a division becomes
quite high, for instance for magnitude changes above about 2, the 'average
speed' will not be a very accurate indicator of what is happening. So at
present my red curve is not to be taken seriously for large star magnitude
variations. It is quite accurate for mag changes below about 1, which covers
most cases we want to investigate.

It is phase shifted for magnitudes below about 3.

I'm working on it.

If I want greater accuracy, I can increase the number of sample points around
the orbit, shorten the arrival time divisions and lengthen the graph on the
screen. My method is still 100% sound.

Not if it ignores the velocity component of the Doppler.

It MUST give the same answer as your
equation.

My suggestion was an equation you could apply to your
existing output to cater for pulsars. It will be quite
diffferent, but if you have ignored the classical
Doppler then it will be wrong too.


My approach if I was to do it your way would be slightly
simpler. You are tracking N=30000 pulses emitted equal
times T apart to take account of the Keplerian orbit. For
each point n you find the distance to the observer and
the speed at emission. From those and the extinction
distance you calculate the time of arrival t(n). Then the
compression ratio is:

[You can assume the distance is the same for all points.
Travel times across the orbit are generally negligible.]

No you can't, the travel time across the orbit is
small (3.8s compared to 1.5 days) but the Doppler
due to the change of distance is significant. You
cannot ignore the 27km/s velocity component.

I'm not ignoring that George.

r = ( t(n) - t(n-1) ) / T

That is related to what I do....but you need lots of sample points for
elliptical orbits.

or better if you want to remove a small phase error:

r = ( t(n+1) - t(n-1) ) / (2T)

yes....better..

The more points the better but you only use two
either side, you don't average lots.

Right, I have used this method to produce brightness curves for both circles
and ellipses. All the infrastructure is already in my program so this was a
fairly simple exercise.

You'll be pleased to hear it produces the same curves...or nearly the same.
Actually your method is better because I found a way to eliminate the averaging
that was always a problem before.

I used a few tricks.
I calculate the travel time from selected points around the orbit then use:
r = ( t(n) - t(n-1) +T) / T
My program has arrays containing all the details about the ellipse that is
used...namely velocity and velocity angle at each of the 30000 or more points
around the orbit..

I use every 100th point and compare its arrival time with that of the adjacent
one.... 99th, 199th...etc., point. This reduces the averaging effect and I
think gives higher accuracy that before. The curves are sharper. My 'Eclipsing
binary' curves are closer to the published ones.

I still have to do the red curve. There's something missing from your equation
I think.



The brightness is


b(n) = 1 / r(n)

and you can trap the infinity at r(n)=0

The "willusory" velocity is

v(n) = c(1 - r(n))

which is always finite.

Then just plot b(n) as the green curve and v(n) as the
red curve versus t(n).

I'm not convinced the method works....I don't think it takes into account the
emission time lag around the orbit.

You just told me to ignore it!

we have been talking about different things here.

All you are really doing is calculating the compression that adjacent pulses
emitted at a certain point on the orbit will experience at distance D. This
doesn't tell you the overall picture..

It is the whole picture, it includes all the factors
I listed at the top which you said I expressed well.

Well the method produces virtually the same brightness curves as mine so it
must be valid. I don't see why it shouldn't be. It is certainly simpler and
faster.
I still have to convert to log output and calculate the magnitude changes but
the program is basically set up to do that.. So that's easy.

.but it might work for small magnitude
changes.

The reason I used the current method was that I wanted to be able to
investigate what happens when the critical distance is exceeded. I don't need
to now because it obviously never IS, due to extinction.

That's harder. For your view of stars you get multiple
overlapping spectra so the star looks like several and
there is no single answer for velocity, you would get a
velocity for each image.

Yes, I wasn't sure what to expect and so I had to use a method that allowed
lots of 'overtaking'....maybe even from orbits widely separated.
Because of extinction, I don't need to worruy about that any more. It is
unlikely that pulses ever overtake other pulses.
I probably would never have bothered to simplify my program if you hadn't
suggested it. So I thank you for that George. This shows the advantages of
cooperation.
I can already see that my curves will now be even closer to the observed ones.

For pulsars a large number of
copies would look like a source with random pulse times.
A few copies would be recognisable as separate pulsars
with pulse streams that could be separated. The identical
mean rates would then be identifiable as two copies.
Neither of these situations ever arises of course.

That appears to be the case.


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.

On 28 Feb 2007 10:02:59 -0800, "PD" wrote:

On Feb 28, 3:21 am, HW@....(Henri Wilson) wrote:
On 27 Feb 2007 16:01:11 -0800, "PD" wrote:

On Feb 27, 5:23 pm, HW@....(Henri Wilson) wrote:
On 27 Feb 2007 07:11:36 -0800, "PD" wrote:

Yes. A frame dependent one...but you don't know what that means Draper.

Sure I do, and on this small point we're in agreement.
So tell me, what makes momentum a physical entity and spacetime not?

Momentum has physical rammifications. Spacetime is just a method of viewing a
physical situation.

Which "physical rammifications" do you have in mind for momentum.
Do you think that 3D space has "physical rammifications"? Does
Euclidean geometry count as a "physical rammification"?

No

So what physical "rammifications" do you have in mind for momentum?

Stop asking trivial questions Draper.

You don't consider the measurable distance between here and the
library being invariant, independent of the orientiation of the
coordinate system, to be a physical "rammification"?

Why the hell should an absolute spatial interval change just because different
people look at it?

Oh crap Draper.
You blokes like to rave about this 'spacetime' when you haven't a clue what you
are even talking about.

Try plotting the snapping of fingers in a 4D representation Draper.

Sure. It's a little blot on a 4D space, kind of like the period at the
end of this sentence.

Hahahojhohoh!

Ah, I see this is news to you. Whenever someone tells you something
you didn't know, your first reaction is to laugh. I can see why you
did so well in school.

It' a curved line...not a dot..

Better still, try something simple like a ball falling to ground. You can plot
that in 2D.

That's not a spacetime event, Henri. That's a sequence of spacetime
events. Now, the ball *landing* on the ground, that's a spacetime
event.

Hahahahwhwhahwahwahawhawhohohohohohoh!

More news, I see.

I only read your messages to get a good laugh Draper....


See? You can't answer a simple question. I asked you where you got
this notion, and all you can do is repeat it.
HW: "2+2=7.43"
PD: "Why Henri, wherever did you get that idea?"
HW: "Don't be an idiot, PD. 2+2=7.43"

Draper, most people here - excluding the ratpack - show a few signs of
intelligence. Why can't you?


Ah, so because you say I should show a few signs of intelligence, that
means I should take your word that 2+2=7.43?

I'm too busy to carry on this stupid conversation.. My time is valuable you
know.



I know you're just trying to waste my time Draper.

'If you can't beat 'em, at least slow them down"

Nah, just pointing out when you say something stupid, Henri. That
normally *does* slow people down. However, in your case, you proceed
full speed ahead. Explains a lot.

Getting desperate, I see....


Are you really this dense?

And what "real physicist" says that a reference frame is defined as
everything that is at rest with respect to a defined point? And which
"real physicist" says that a reference frame is simply something that
can be used to compare velocities? You still haven't answered either
of these questions.

Why don't you ask captain Roberts.

Why? I asked you about YOUR idea. Now you deflect. Avoiding, Henri?

I'm not here to educate YOU Draper. There are institutions set up to do those
things...although in your case, I doubt if they would persevere...



Of course the ant is not in the frame of the picture. The frame of a
picture forms a boundary around a picture. What does this have to do
with a reference frame, Henri? Were you thinking that a reference
frame is a box around a collection of objects?

No but you apparently are.

I didn't bring up ants and a picture frame. You did.
I didn't say a reference frame is everything at rest with respect to a
defined point. You did.

It is.

I said that everything that is moving with respect to a defined point
is *also* in that frame. You apparently don't think so. I've asked you
where on earth you got that idea. You've yet to answer.

The frame of a struck tennis ball is NOT the frame of the court and never will
be.

Is life one big game of dodge-ball for you, Henri?

Learn some physics Draper.


PD



"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.

On Feb 28, 2:09 pm, HW@....(Henri Wilson) wrote:
On 28 Feb 2007 10:02:59 -0800, "PD" wrote:





On Feb 28, 3:21 am, HW@....(Henri Wilson) wrote:
On 27 Feb 2007 16:01:11 -0800, "PD" wrote:

On Feb 27, 5:23 pm, HW@....(Henri Wilson) wrote:
On 27 Feb 2007 07:11:36 -0800, "PD" wrote:

Yes. A frame dependent one...but you don't know what that means Draper.

Sure I do, and on this small point we're in agreement.
So tell me, what makes momentum a physical entity and spacetime not?

Momentum has physical rammifications. Spacetime is just a method of viewing a
physical situation.

Which "physical rammifications" do you have in mind for momentum.
Do you think that 3D space has "physical rammifications"? Does
Euclidean geometry count as a "physical rammification"?

No

So what physical "rammifications" do you have in mind for momentum?

Stop asking trivial questions Draper.

Why? Trivial questions should be really simple to answer. What's the
really simple answer, Henri?


You don't consider the measurable distance between here and the
library being invariant, independent of the orientiation of the
coordinate system, to be a physical "rammification"?

Why the hell should an absolute spatial interval change just because different
people look at it?

A good question. Right way to approach it is to find out first if it
really happens or not. Once you find out, then you can ask why it
happens. Much more productive than deciding that, because you can't
figure out how it would happen, it must not happen, and therefore
there's no need to find out if it really happens or not.


Oh crap Draper.
You blokes like to rave about this 'spacetime' when you haven't a clue what you
are even talking about.

Try plotting the snapping of fingers in a 4D representation Draper.

Sure. It's a little blot on a 4D space, kind of like the period at the
end of this sentence.

Hahahojhohoh!

Ah, I see this is news to you. Whenever someone tells you something
you didn't know, your first reaction is to laugh. I can see why you
did so well in school.

It' a curved line...not a dot..

The snapping of fingers is a curved line, Henri?

Oh, you must have meant something else. No matter, you don't read -- I
understand.

Are you confusing a trajectory or a world line with a spacetime event,
Henri?
Would you like a reading reference on the meaning of these terms,
Henri?
http://en.wikipedia.org/wiki/Spacetime#Basic_concepts


Better still, try something simple like a ball falling to ground. You can plot
that in 2D.

That's not a spacetime event, Henri. That's a sequence of spacetime
events. Now, the ball *landing* on the ground, that's a spacetime
event.

Hahahahwhwhahwahwahawhawhohohohohohoh!

More news, I see.

I only read your messages to get a good laugh Draper....

See? You can't answer a simple question. I asked you where you got
this notion, and all you can do is repeat it.
HW: "2+2=7.43"
PD: "Why Henri, wherever did you get that idea?"
HW: "Don't be an idiot, PD. 2+2=7.43"

Draper, most people here - excluding the ratpack - show a few signs of
intelligence. Why can't you?

Ah, so because you say I should show a few signs of intelligence, that
means I should take your word that 2+2=7.43?

I'm too busy to carry on this stupid conversation.. My time is valuable you
know.

Oh, yes, I know. So valuable that you simply don't have the time to
post stupidities on Usenet.




I know you're just trying to waste my time Draper.

'If you can't beat 'em, at least slow them down"

Nah, just pointing out when you say something stupid, Henri. That
normally *does* slow people down. However, in your case, you proceed
full speed ahead. Explains a lot.

Getting desperate, I see....

Not at all. It's an endless source of idle amusement for me. You say
something stupid. I point out how stupid it is. You call me desperate
for being amused at your stupidity and issue more stupidities. I'm
amused at your calling me desperate and the additional stupidities.
Great fun.


Are you really this dense?

And what "real physicist" says that a reference frame is defined as
everything that is at rest with respect to a defined point? And which
"real physicist" says that a reference frame is simply something that
can be used to compare velocities? You still haven't answered either
of these questions.

Why don't you ask captain Roberts.

Why? I asked you about YOUR idea. Now you deflect. Avoiding, Henri?

I'm not here to educate YOU Draper. There are institutions set up to do those
things...although in your case, I doubt if they would persevere...

So far, I've yet to see an institution that see things as you do,
aside from Ward D down at Sunshine Acres. Which one do you recommend,
Henri? Be sure to point out one that you can be sure sees things the
way you do.




Of course the ant is not in the frame of the picture. The frame of a
picture forms a boundary around a picture. What does this have to do
with a reference frame, Henri? Were you thinking that a reference
frame is a box around a collection of objects?

No but you apparently are.

I didn't bring up ants and a picture frame. You did.
I didn't say a reference frame is everything at rest with respect to a
defined point. You did.

It is.

I said that everything that is moving with respect to a defined point
is *also* in that frame. You apparently don't think so. I've asked you
where on earth you got that idea. You've yet to answer.

The frame of a struck tennis ball is NOT the frame of the court and never will
be.

Really? Then if there was an origin assigned to one corner of the
court, and the baseline was assigned to lie on one axis, and the
sideline was assigned to lie on the other axis, then how would you
measure the speed of the tennis ball at any instant, Henri? After all,
it's not in that frame!


Is life one big game of dodge-ball for you, Henri?

Learn some physics Draper.

Well, yes, it appears life IS one big game of dodge-ball for you,
Henri.

PD

On 28 Feb 2007 13:55:50 -0800, "PD" wrote:

On Feb 28, 2:09 pm, HW@....(Henri Wilson) wrote:
On 28 Feb 2007 10:02:59 -0800, "PD" wrote:




So what physical "rammifications" do you have in mind for momentum?

Stop asking trivial questions Draper.

Why? Trivial questions should be really simple to answer. What's the
really simple answer, Henri?

Go away draper.
If you want to see how physics really works, tune in to my discussions with
George. He's a relativist but certainly doesn't belong to the ratpack.

You don't consider the measurable distance between here and the
library being invariant, independent of the orientiation of the
coordinate system, to be a physical "rammification"?

Why the hell should an absolute spatial interval change just because different
people look at it?

A good question. Right way to approach it is to find out first if it
really happens or not. Once you find out, then you can ask why it
happens. Much more productive than deciding that, because you can't
figure out how it would happen, it must not happen, and therefore
there's no need to find out if it really happens or not.

....and since there is no way of finding out, you think you're safe.

Oh crap Draper.
You blokes like to rave about this 'spacetime' when you haven't a clue what you
are even talking about.

Try plotting the snapping of fingers in a 4D representation Draper.

Sure. It's a little blot on a 4D space, kind of like the period at the
end of this sentence.

Hahahojhohoh!

Ah, I see this is news to you. Whenever someone tells you something
you didn't know, your first reaction is to laugh. I can see why you
did so well in school.

It' a curved line...not a dot..

The snapping of fingers is a curved line, Henri?

Lots of curved lines actually.
One for each atom.

Oh, you must have meant something else. No matter, you don't read -- I
understand.

Are you confusing a trajectory or a world line with a spacetime event,
Henri?
Would you like a reading reference on the meaning of these terms,
Henri?
http://en.wikipedia.org/wiki/Spacetime#Basic_concepts

No thanks. ...written by a crazed relativist no doubt.

They don't exists and are completely unnecessary for the understanding of space
and the true relativity..
Big words impress small minds that want to feel important.


'If you can't beat 'em, at least slow them down"

Nah, just pointing out when you say something stupid, Henri. That
normally *does* slow people down. However, in your case, you proceed
full speed ahead. Explains a lot.

Getting desperate, I see....

Not at all. It's an endless source of idle amusement for me. You say
something stupid. I point out how stupid it is. You call me desperate
for being amused at your stupidity and issue more stupidities. I'm
amused at your calling me desperate and the additional stupidities.
Great fun.

well i'm not wasting any more time on you Draper.

Why don't you ask captain Roberts.

Why? I asked you about YOUR idea. Now you deflect. Avoiding, Henri?

I'm not here to educate YOU Draper. There are institutions set up to do those
things...although in your case, I doubt if they would persevere...

So far, I've yet to see an institution that see things as you do,
aside from Ward D down at Sunshine Acres. Which one do you recommend,
Henri? Be sure to point out one that you can be sure sees things the
way you do.

No doubt ward D is full of relativists right now...


Of course the ant is not in the frame of the picture. The frame of a
picture forms a boundary around a picture. What does this have to do
with a reference frame, Henri? Were you thinking that a reference
frame is a box around a collection of objects?

No but you apparently are.

I didn't bring up ants and a picture frame. You did.
I didn't say a reference frame is everything at rest with respect to a
defined point. You did.

It is.

I said that everything that is moving with respect to a defined point
is *also* in that frame. You apparently don't think so. I've asked you
where on earth you got that idea. You've yet to answer.

The frame of a struck tennis ball is NOT the frame of the court and never will
be.

Really? Then if there was an origin assigned to one corner of the
court, and the baseline was assigned to lie on one axis, and the
sideline was assigned to lie on the other axis, then how would you
measure the speed of the tennis ball at any instant, Henri? After all,
it's not in that frame!

Yopu really should give up Draper, this is just not your scene.

The problem is one of measuring the ball's frame relative to the court's frame.
......quite simple really.

If you knew any physics you would be able to answer these simple questions
yourself.

Is life one big game of dodge-ball for you, Henri?

Learn some physics Draper.

Well, yes, it appears life IS one big game of dodge-ball for you,
Henri.

PD


"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.

On 28 Feb 2007 06:05:46 -0800, "George Dishman"
wrote:



The last part seems to be adding an unnecessary layer of
complexity.

My approach if I was to do it your way would be slightly
simpler. You are tracking N=30000 pulses emitted equal
times T apart to take account of the Keplerian orbit. For
each point n you find the distance to the observer and
the speed at emission. From those and the extinction
distance you calculate the time of arrival t(n). Then the
compression ratio is:

[You can assume the distance is the same for all points.
Travel times across the orbit are generally negligible.]

No you can't, the travel time across the orbit is
small (3.8s compared to 1.5 days) but the Doppler
due to the change of distance is significant. You
cannot ignore the 27km/s velocity component.

r = ( t(n) - t(n-1) ) / T

That is related to what I do....but you need lots of sample points for
elliptical orbits.

or better if you want to remove a small phase error:

r = ( t(n+1) - t(n-1) ) / (2T)

yes....better..

The more points the better but you only use two
either side, you don't average lots.

The brightness is

b(n) = 1 / r(n)

and you can trap the infinity at r(n)=0

The "willusory" velocity is

v(n) = c(1 - r(n))

which is always finite.

Then just plot b(n) as the green curve and v(n) as the
red curve versus t(n).


I was trying to determine why your method produces slightly different curves
from mine and found there is a problem with yours.

The time intervals for plotting b(n) are not all equal at the observer end...
In other words, when I plot b(n) on the y axis, I have to adjust the intervals
on the x axis (time) to take into account this nonlinearity. I can probably
still do it and will persevere.



"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.

HW@....(Henri Wilson) wrote in
:

The problem is one of measuring the ball's frame relative to the court's
frame. .....quite simple really.



Careful, Henri, you just stepped into a trap. You will have a problem when
you try that trick on a photon.




--
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 Feb 28, 4:42 pm, HW@....(Henri Wilson) wrote:
On 28 Feb 2007 13:55:50 -0800, "PD" wrote:

So what physical "rammifications" do you have in mind for momentum?

Stop asking trivial questions Draper.

Why? Trivial questions should be really simple to answer. What's the
really simple answer, Henri?

Go away draper.
If you want to see how physics really works, tune in to my discussions with
George. He's a relativist but certainly doesn't belong to the ratpack.

You don't consider the measurable distance between here and the
library being invariant, independent of the orientiation of the
coordinate system, to be a physical "rammification"?

Why the hell should an absolute spatial interval change just because different
people look at it?

A good question. Right way to approach it is to find out first if it
really happens or not. Once you find out, then you can ask why it
happens. Much more productive than deciding that, because you can't
figure out how it would happen, it must not happen, and therefore
there's no need to find out if it really happens or not.

...and since there is no way of finding out, you think you're safe.

Sure there is a way. What makes you think there's not a way?
Now, getting you to read the *result* of doing that, that's another
matter...


Oh crap Draper.
You blokes like to rave about this 'spacetime' when you haven't a clue what you
are even talking about.

Try plotting the snapping of fingers in a 4D representation Draper.

Sure. It's a little blot on a 4D space, kind of like the period at the
end of this sentence.

Hahahojhohoh!

Ah, I see this is news to you. Whenever someone tells you something
you didn't know, your first reaction is to laugh. I can see why you
did so well in school.

It' a curved line...not a dot..

The snapping of fingers is a curved line, Henri?

Lots of curved lines actually.
One for each atom.

Oh, you must have meant something else. No matter, you don't read -- I
understand.

Are you confusing a trajectory or a world line with a spacetime event,
Henri?
Would you like a reading reference on the meaning of these terms,
Henri?
http://en.wikipedia.org/wiki/Spacetime#Basic_concepts

No thanks. ...written by a crazed relativist no doubt.

Ah, so you resort to clapping your hands over your ears and saying,
"La-la-la-la-la! It's what I say it is, and not what anyone else says
it is, because I say so, and you can't make me do otherwise! La-la-la-
la-la!"

Well done, Ralph. Sure notched up in the esteem category there.


They don't exists and are completely unnecessary for the understanding of space
and the true relativity..
Big words impress small minds that want to feel important.

"Event", "world" and "line" are all big words, Hank? What's a small
word to you?
And there's an interesting phrase: "the true relativity". I wonder
what that means. Do you have any idea, Henri?


'If you can't beat 'em, at least slow them down"

Nah, just pointing out when you say something stupid, Henri. That
normally *does* slow people down. However, in your case, you proceed
full speed ahead. Explains a lot.

Getting desperate, I see....

Not at all. It's an endless source of idle amusement for me. You say
something stupid. I point out how stupid it is. You call me desperate
for being amused at your stupidity and issue more stupidities. I'm
amused at your calling me desperate and the additional stupidities.
Great fun.

well i'm not wasting any more time on you Draper.

You mean like right now?


Why don't you ask captain Roberts.

Why? I asked you about YOUR idea. Now you deflect. Avoiding, Henri?

I'm not here to educate YOU Draper. There are institutions set up to do those
things...although in your case, I doubt if they would persevere...

So far, I've yet to see an institution that see things as you do,
aside from Ward D down at Sunshine Acres. Which one do you recommend,
Henri? Be sure to point out one that you can be sure sees things the
way you do.

No doubt ward D is full of relativists right now...


Still no sign of that institution of learning you're recommending,
Henri. What was that again?


Of course the ant is not in the frame of the picture. The frame of a
picture forms a boundary around a picture. What does this have to do
with a reference frame, Henri? Were you thinking that a reference
frame is a box around a collection of objects?

No but you apparently are.

I didn't bring up ants and a picture frame. You did.
I didn't say a reference frame is everything at rest with respect to a
defined point. You did.

It is.

I said that everything that is moving with respect to a defined point
is *also* in that frame. You apparently don't think so. I've asked you
where on earth you got that idea. You've yet to answer.

The frame of a struck tennis ball is NOT the frame of the court and never will
be.

Really? Then if there was an origin assigned to one corner of the
court, and the baseline was assigned to lie on one axis, and the
sideline was assigned to lie on the other axis, then how would you
measure the speed of the tennis ball at any instant, Henri? After all,
it's not in that frame!

Yopu really should give up Draper, this is just not your scene.

The problem is one of measuring the ball's frame relative to the court's frame.
.....quite simple really.

Ah, so in order to measure the velocity of the ball relative to the
court, we have to measure the velocity of the ball's *frame* relative
to the court's *frame*? Sort of like a "Have your people talk to my
people" kind of thing?

Tell me, Henri, when a cop catches you speeding, does his radar gun
measure the speed of the car's frame relative to the gun's frame? How
does it do that, exactly?


If you knew any physics you would be able to answer these simple questions
yourself.

Simple? You're trying to tell me I can't measure a ball's velocity
relative to a tennis court. I have to measure the ball's *frame*
relative to the court's *frame*. That's simple?


Is life one big game of dodge-ball for you, Henri?

Learn some physics Draper.

Well, yes, it appears life IS one big game of dodge-ball for you,
Henri.

PD

"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.- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

On 28 Feb, 19:58, HW@....(Henri Wilson) wrote:
On 28 Feb 2007 06:05:46 -0800, "George Dishman" wrote:
On 27 Feb, 22:11, HW@....(Henri Wilson) wrote:
On Tue, 27 Feb 2007 09:22:01 -0000, "George Dishman"
....
[You can assume the distance is the same for all points.
Travel times across the orbit are generally negligible.]

No you can't, the travel time across the orbit is
small (3.8s compared to 1.5 days) but the Doppler
due to the change of distance is significant. You
cannot ignore the 27km/s velocity component.

I'm not ignoring that George.

OK, if you only ignore the travel time, that's
not a problem. It would cause a slight shift on
the x axis but it will always be small compared
to the orbital period.

The more points the better but you only use two
either side, you don't average lots.

Right, I have used this method to produce brightness curves for both circles
and ellipses. All the infrastructure is already in my program so this was a
fairly simple exercise.

You'll be pleased to hear it produces the same curves...or nearly the same.
Actually your method is better because I found a way to eliminate the averaging
that was always a problem before.

Excellent

I used a few tricks.
I calculate the travel time from selected points around the orbit then use:
r = ( t(n) - t(n-1) +T) / T

I guess your t(n) is travel time rather than
arrival time then.

I still have to do the red curve. There's something missing from your equation
I think.

Perhaps, it is based on the assumption that your
green curve has no simplifications so there might
be some 'features' to cope with.

I'm not convinced the method works....I don't think it takes into account the
emission time lag around the orbit.

You just told me to ignore it!

we have been talking about different things here.

OK.

It is the whole picture, it includes all the factors
I listed at the top which you said I expressed well.

Well the method produces virtually the same brightness curves as mine so it
must be valid. I don't see why it shouldn't be. It is certainly simpler and
faster.

I think sometimes you are so defensive you assume I am
criticising when in fact I am just suggesting program
improvements. I have a lot of experience in efficient
coding techniques and can sometimes see shortcuts that
will save you effort.


The reason I used the current method was that I wanted to be able to
investigate what happens when the critical distance is exceeded. I don't need
to now because it obviously never IS, due to extinction.

That's harder. For your view of stars you get multiple
overlapping spectra so the star looks like several and
there is no single answer for velocity, you would get a
velocity for each image.

Yes, I wasn't sure what to expect and so I had to use a method that allowed
lots of 'overtaking'....maybe even from orbits widely separated.
Because of extinction, I don't need to worruy about that any more. It is
unlikely that pulses ever overtake other pulses.

Yes, in terms of the physics, that should ring
alarm bells. Why is there that coincidence that
the extinction is always just high enough to
prevent overtaking but sometimes just that little
bit less so that we see brightness variations.
I'll leave you to mull over that one ;-)

I probably would never have bothered to simplify my program if you hadn't
suggested it. So I thank you for that George. This shows the advantages of
cooperation.

Glad I could help.

I can already see that my curves will now be even closer to the observed ones.

For pulsars a large number of
copies would look like a source with random pulse times.
A few copies would be recognisable as separate pulsars
with pulse streams that could be separated. The identical
mean rates would then be identifiable as two copies.
Neither of these situations ever arises of course.

That appears to be the case.

Certainly for all detecteded so far. An overlapping
pulsar pattern would initially look like a case of
micro-lensing producing two images but normally such
an alignment would be very short-lived and a simple
analysis would show a remarkable phase relationship.
It would certainly be headline news while people
tried to explain it.

George

On 28 Feb, 22:54, HW@....(Henri Wilson) wrote:
On 28 Feb 2007 06:05:46 -0800, "George Dishman" wrote:
....
r = ( t(n) - t(n-1) ) / T

That is related to what I do....but you need lots of sample points for
elliptical orbits.

or better if you want to remove a small phase error:

r = ( t(n+1) - t(n-1) ) / (2T)

yes....better..

The more points the better but you only use two
either side, you don't average lots.

The brightness is

b(n) = 1 / r(n)

and you can trap the infinity at r(n)=0

The "willusory" velocity is

v(n) = c(1 - r(n))

which is always finite.

Then just plot b(n) as the green curve and v(n) as the
red curve versus t(n).

I was trying to determine why your method produces slightly different curves
from mine and found there is a problem with yours.

The time intervals for plotting b(n) are not all equal at the observer end...

I know, that's why I said plot "versus t(n)". The
values of t(n) are the arrival times which are
your x axis. I have no idea how your were working
out the x coordinate when you were averaging
multiple pulses with different arrival times,
presumably you averaged that in some way too, but
you were binning so you should have been selecting
the array elements to average depending on whether
t(n) fell within the bin.

In other words, when I plot b(n) on the y axis, I have to adjust the intervals
on the x axis (time) to take into account this nonlinearity. I can probably
still do it and will persevere.

It is an essential part of producing the curve and
I had assumed you were already doing it. It is
particularly important if you want to look at
distances beyond critical because the t(n) values
start going backwards as later pulses overtake
earlier ones.

George