What's up with gravity wave detection?

"A" == Androcles writes:

A "Joseph Lazio" wrote in message
A ...

I don't think the current [gravitational wave] emission levels from
PSR B1913+16 or PSR J0737-3039 would be detectable. However, in a
few million years, as they continue to in-spiral, the gravitational
wave emission level is expected to increase. Obviously, we won't
be around to see that, but there may be other systems in the nearby
Universe that would be in the last stages of in-spiral.

A Thus, this is a prediction that's a bit hard to test.:-)

Well, it is difficult to test for these two systems obviously.
However, these are not the only two such binary neutron star systems
in the Universe (nor are they the only two known). PSR J0737-3039 has
an orbital period of 2.4 hr. It's reasonable to ask, even reasonable
to assume, that there are other binary neutron star systems with even
tighter periods. These would have higher levels of gravitational wave
emission. That is a testable prediction.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
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"Joseph Lazio" wrote in message
...
|
| "A" == Androcles writes:
|
| A "Joseph Lazio" wrote in message
| A ...
|
| I don't think the current [gravitational wave] emission levels from
| PSR B1913+16 or PSR J0737-3039 would be detectable. However, in a
| few million years, as they continue to in-spiral, the gravitational
| wave emission level is expected to increase. Obviously, we won't
| be around to see that, but there may be other systems in the nearby
| Universe that would be in the last stages of in-spiral.
|
| A Thus, this is a prediction that's a bit hard to test.:-)
|
| Well, it is difficult to test for these two systems obviously.
| However, these are not the only two such binary neutron star systems
| in the Universe (nor are they the only two known). PSR J0737-3039 has
| an orbital period of 2.4 hr. It's reasonable to ask, even reasonable
| to assume, that there are other binary neutron star systems with even
| tighter periods. These would have higher levels of gravitational wave
| emission. That is a testable prediction.

So where are the gravity waves?
As I stated earlier, and perhaps it didn't register, the largest negative
going gravity pulse imaginable would be for Proxima Centauri to completely
annihilate in a cataclysmic supernova, no remnant left, and it still would
be too small to register when that pulse reached us. By the same token, if
the same thing happened to Sirius, twice as far away, the pulse would be
only one quarter as large. At 16 light years, one sixteenth as great. You
are talking of measuring a minor wave, far smaller than any supernova could
emit, at an enormous distance. I just don't see how you hope to measure it.
The inverse square law has you beaten ever time.
Androcles


|
| --
| Lt. Lazio, HTML police | e-mail:
| No means no, stop rape. | http://patriot.net/%7Ejlazio/
| sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

"Australopithecus Afarensis" wrote in message news:zQXTc.100010$sh.86278@fed1read06...
Most likely LIGO will detect gravitational waves.
See: http://www.ligo.caltech.edu/
http:/www.edu-observatory.org/eo/cosmology.html

It is very interesting how institutions would spend millions of dollars
trying to detect something that has not been thoroughly understood. As I
read in Scientific American a year or two ago, LIGO was chosen to be built
in places where noise generated by human activities are at near maximum.
This means LIGO's detection of gravitational waves is subjected to broad and
creative interpretations of data which can easily be explained by something
else.


It's not that interesting since scientists
usually spend billions of dollars doing nothing.

And since saying that gravity waves are
thoroughly understod is the same thing
as gravity particles are thoroughly
understood, both statements which
are quark-quantum crapola, the experiment
is obviously not meant to be understood by quantum-chemists,
or astro-physicists, since it has no magents involved.

Since to be being with the experiment is not
even detecting waves. The wave detection
is a third order effect of the entire setup.
Since Laser interferometry can't "detect"
ANYTHING, nevermind a gravity wave.

On Wed, 18 Aug 2004 13:02:57 GMT, "Androcles"
wrote:

[snip]

| As I pointed out originally, the greatest pulse detectable would be
negative
| going and the total annihilation of a star. If Proxima Centauri vanished
| overnight, what effect would be detectable, gravitationally, upon our
solar
| system ?
|
| Reform your question in a way that makes sense. Proxima Centauri
| cannot just vanish. Perhaps convert it to photons, or neutrinos mabey,
| but it cannot just vanish.

Had you been following, you would have realized I suggested a complete
conversion of all mass to radiation. I'm not about to repeat myself every
time for your nit-picking.

**mutter** missing the point... **mutter*

The power of emitted gravitational radiation emitted depends rather
deeply on how fast and in what way the star is abused. You also are
NOT going to be able to convert the entire star into photons, unless
you are going to bring in a tenth of a stellar mass of antimatter in
to join it.

|
| I submit the answer to be : none at all that was detectable. The entire
| solar system as a group might change its path with respect to the
galactic
| centre, but we would not be aware of it. I fail to see how we could
expect a
| pulsar 250 times further away could have greater signal
|
| Let see your calculations! For once back up your statements!

Go away, idiot. If you can't assess quantities without working numbers you
don't belong in any form of science.

Gosh Androcles, that is rather interesting. You think I am an idiot
because I cannot make a prediction about something when I don't have
enough information? What the **** kind of engineer were you?

I ask you to support your statements with a simple calculation to show
that converting the star into photons, over an UNDEFINED amount of
time, using an UNDEFINED method, would result in the largest possible
gravitational wave.

You blow me off, because you can't. To be expected, because you are a
clueless blowhard.


|
| How much energy would be released in the mode you choose to destroy
| Proxima Centauri with?

Irrelevant. I was conducting a thought experiment on the maximum imaginable
negative going gravity pulse being detectable and you are responding to a
follow up.
Androcles.


Only because you lack the knowledge to understand why I would ask such
questions.

Your stupidity continues to amuse and amaze. I continue to wonder how
a person like you managed to function as an engineer, if you ever did.

On 18 Aug 2004 13:33:05 -0400, Joseph Lazio
wrote:


"A" == Androcles writes:

A "Joseph Lazio" wrote in message
A ...

I don't think the current [gravitational wave] emission levels from
PSR B1913+16 or PSR J0737-3039 would be detectable. However, in a
few million years, as they continue to in-spiral, the gravitational
wave emission level is expected to increase. Obviously, we won't
be around to see that, but there may be other systems in the nearby
Universe that would be in the last stages of in-spiral.

A Thus, this is a prediction that's a bit hard to test.:-)

Well, it is difficult to test for these two systems obviously.
However, these are not the only two such binary neutron star systems
in the Universe (nor are they the only two known). PSR J0737-3039 has
an orbital period of 2.4 hr. It's reasonable to ask, even reasonable
to assume, that there are other binary neutron star systems with even
tighter periods. These would have higher levels of gravitational wave
emission. That is a testable prediction.

Binary pulsars are...interesting. They provide a fun playground for a
whole array of theories.

Do keep in mind that only 6 or so are known to exist.

"eric gisse" wrote in message
...
| On Wed, 18 Aug 2004 13:02:57 GMT, "Androcles"
| wrote:
|
| [snip]
|
| | As I pointed out originally, the greatest pulse detectable would be
| negative
| | going and the total annihilation of a star. If Proxima Centauri
vanished
| | overnight, what effect would be detectable, gravitationally, upon our
| solar
| | system ?
| |
| | Reform your question in a way that makes sense. Proxima Centauri
| | cannot just vanish. Perhaps convert it to photons, or neutrinos mabey,
| | but it cannot just vanish.
|
| Had you been following, you would have realized I suggested a complete
| conversion of all mass to radiation. I'm not about to repeat myself every
| time for your nit-picking.
|
| **mutter** missing the point... **mutter*
|
| The power of emitted gravitational radiation emitted depends rather
| deeply on how fast and in what way the star is abused. You also are
| NOT going to be able to convert the entire star into photons, unless
| you are going to bring in a tenth of a stellar mass of antimatter in
| to join it.

So you missed the point. Not my problem. I don't care about the mechanism.
I'm only considering the negative going gravity pulse, suddenly switching
off the gravity as you would a light bulb in your living room. Are you
really too dumb to imagine that?


|
| |
| | I submit the answer to be : none at all that was detectable. The
entire
| | solar system as a group might change its path with respect to the
| galactic
| | centre, but we would not be aware of it. I fail to see how we could
| expect a
| | pulsar 250 times further away could have greater signal
| |
| | Let see your calculations! For once back up your statements!
|
| Go away, idiot. If you can't assess quantities without working numbers
you
| don't belong in any form of science.
|
| Gosh Androcles, that is rather interesting. You think I am an idiot
| because I cannot make a prediction about something when I don't have
| enough information?

Yes. I do. All the information you need is the instant turn off of the
gravity of a nearby star, and you can't even consider that without pondering
what caused it.

What the **** kind of engineer were you?
A ****ing good one, and I don't have to worry about whether the bulb burned
out, the breaker tripped, a fuse blew, there was a power cut or someone
threw the switch to know the light went out, idiot.


|
| I ask you to support your statements with a simple calculation to show
| that converting the star into photons, over an UNDEFINED amount of
| time, using an UNDEFINED method, would result in the largest possible
| gravitational wave.
|
| You blow me off, because you can't. To be expected, because you are a
| clueless blowhard.

Put you own figures in. All I suggested was the most powerful gravity pulse
imaginable would not be detectable, and you want it quantified.
Six orders of magnitude is close enough. **** off, moron.

|
|
| |
| | How much energy would be released in the mode you choose to destroy
| | Proxima Centauri with?
|
| Irrelevant. I was conducting a thought experiment on the maximum
imaginable
| negative going gravity pulse being detectable and you are responding to a
| follow up.
| Androcles.
|
|
| Only because you lack the knowledge to understand why I would ask such
| questions.

Moron.
|
| Your stupidity continues to amuse and amaze. I continue to wonder how
| a person like you managed to function as an engineer, if you ever did.

Total moron.
Androcles.

"A" == Androcles writes:

A "Joseph Lazio" wrote in message
A ...

[PSR B1913+16 and PSR J0737-3039] are not the only two such binary
neutron star systems in the Universe (...). PSR J0737-3039 has an
orbital period of 2.4 hr. It's reasonable to ask, even reasonable
to assume, that there are other binary neutron star systems with
even tighter periods. These would have higher levels of
gravitational wave emission. That is a testable rediction.

A So where are the gravity waves?

The fact that none have been detected means that there are no binary
neutron stars in the final in-spiral stages "close by."

A As I stated earlier, and perhaps it didn't register, the largest
A negative going gravity pulse imaginable would be for Proxima
A Centauri to completely annihilate in a cataclysmic supernova, no
A remnant left, and it still would be too small to register when that
A pulse reached us.

As I noted earlier, I still don't understand what you mean by
"negative" in this context, and I note that you don't provide any
quantitative estimates. In a talk by Ott, he comments on
gravitational wave detectability
(URL:http://jupiter.as.arizona.edu/~burrows/scidac/gr_talk101601.html,
slide 33), comments that are based on Thorne (1997).

He predicts that LIGO would be capable of detecting a Galactic
supernova within the range of a few kiloparsec.

--
Lt. Lazio, HTML police | e-mail:
No means no, stop rape. | http://patriot.net/%7Ejlazio/
sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

On Thu, 19 Aug 2004 00:02:45 GMT, "Androcles"
wrote:


"eric gisse" wrote in message
.. .
| On Wed, 18 Aug 2004 13:02:57 GMT, "Androcles"
| wrote:
|
| [snip]
|
| | As I pointed out originally, the greatest pulse detectable would be
| negative
| | going and the total annihilation of a star. If Proxima Centauri
vanished
| | overnight, what effect would be detectable, gravitationally, upon our
| solar
| | system ?
| |
| | Reform your question in a way that makes sense. Proxima Centauri
| | cannot just vanish. Perhaps convert it to photons, or neutrinos mabey,
| | but it cannot just vanish.
|
| Had you been following, you would have realized I suggested a complete
| conversion of all mass to radiation. I'm not about to repeat myself every
| time for your nit-picking.
|
| **mutter** missing the point... **mutter*
|
| The power of emitted gravitational radiation emitted depends rather
| deeply on how fast and in what way the star is abused. You also are
| NOT going to be able to convert the entire star into photons, unless
| you are going to bring in a tenth of a stellar mass of antimatter in
| to join it.

So you missed the point. Not my problem. I don't care about the mechanism.

You expose your ignorance with that statement. The mechanism matters.

I'm only considering the negative going gravity pulse, suddenly switching
off the gravity as you would a light bulb in your living room. Are you
really too dumb to imagine that?

You said you wanted to convert the star into photons...which happen to
contribute to curvature and thus gravity.

Since you assume yourself profecient enough in GR to discuss
generation of gravitational radiation, I find it AMAZING that you
managed to learn GR without knowing what the stress-energy tensor is,
and how matter and energy fit into it.



|
| |
| | I submit the answer to be : none at all that was detectable. The
entire
| | solar system as a group might change its path with respect to the
| galactic
| | centre, but we would not be aware of it. I fail to see how we could
| expect a
| | pulsar 250 times further away could have greater signal
| |
| | Let see your calculations! For once back up your statements!
|
| Go away, idiot. If you can't assess quantities without working numbers
you
| don't belong in any form of science.
|
| Gosh Androcles, that is rather interesting. You think I am an idiot
| because I cannot make a prediction about something when I don't have
| enough information?

Yes. I do. All the information you need is the instant turn off of the
gravity of a nearby star, and you can't even consider that without pondering
what caused it.

No, you wanted to convert the star to photons. That is not the same
thing. If you had an education in modern physics, you would know that.


What the **** kind of engineer were you?
A ****ing good one, and I don't have to worry about whether the bulb burned
out, the breaker tripped, a fuse blew, there was a power cut or someone
threw the switch to know the light went out, idiot.

I really doubt that you could be a good engineer with the kind of
ignorance you display here. It most likely was not any engineering
position in which you had to build anything, because building needs
planning and planning needs math.

My guess is you managed engineers, and thus you assume you are an
engineer.



|
| I ask you to support your statements with a simple calculation to show
| that converting the star into photons, over an UNDEFINED amount of
| time, using an UNDEFINED method, would result in the largest possible
| gravitational wave.
|
| You blow me off, because you can't. To be expected, because you are a
| clueless blowhard.

Put you own figures in. All I suggested was the most powerful gravity pulse
imaginable would not be detectable, and you want it quantified.

Exactly! You make an assertion that is odd, and I ask that you
quantify it or somehow back it up.

If you actually did any calculations instead of handwaving, you would
be able to tell me how much energy would be pumped into gravitational
radiation.

Six orders of magnitude is close enough. **** off, moron.

Why don't you show the calculation? How do you know the wave would be
6 orders of magnitude too small to detect?


|
|
| |
| | How much energy would be released in the mode you choose to destroy
| | Proxima Centauri with?
|
| Irrelevant. I was conducting a thought experiment on the maximum
imaginable
| negative going gravity pulse being detectable and you are responding to a
| follow up.
| Androcles.
|
|
| Only because you lack the knowledge to understand why I would ask such
| questions.

Moron.

Yes, you are.

Gravitational radiation is a prediction of General Relativity, which
you don't have any hope of understanding in your lifetime.

Your entire post is riddled with nuggets of ignorance and abject
stupidity. I can't say that im surprised, really.

|
| Your stupidity continues to amuse and amaze. I continue to wonder how
| a person like you managed to function as an engineer, if you ever did.

Total moron.

Only on days which are prime. Today is not one of those days. I was
probably stupid yesteday, though.

Androcles.




Followups sent to alt.stupidity

"Joseph Lazio" wrote in message
...
| "A" == Androcles writes:
|
| A "Joseph Lazio" wrote in message
| A ...
|
| [PSR B1913+16 and PSR J0737-3039] are not the only two such binary
| neutron star systems in the Universe (...). PSR J0737-3039 has an
| orbital period of 2.4 hr. It's reasonable to ask, even reasonable
| to assume, that there are other binary neutron star systems with
| even tighter periods. These would have higher levels of
| gravitational wave emission. That is a testable rediction.
|
| A So where are the gravity waves?
|
| The fact that none have been detected means that there are no binary
| neutron stars in the final in-spiral stages "close by."

So they are too far away to be detectable. That's what I said.
Hence it is a waste of time building LIGO or any other gravity wave
detector.



|
| A As I stated earlier, and perhaps it didn't register, the largest
| A negative going gravity pulse imaginable would be for Proxima
| A Centauri to completely annihilate in a cataclysmic supernova, no
| A remnant left, and it still would be too small to register when that
| A pulse reached us.
|
| As I noted earlier, I still don't understand what you mean by
| "negative" in this context, and I note that you don't provide any
| quantitative estimates.

Negative-going simply means from some to none. So measure the gravity
effect of Proxima Centauri as it is now, then the effect if it disappeared,
and the difference is the greatest gravity pulse imaginable.
If you want to quantify the force, use G.(M1+M2)/r^2 where M1 is the mass
of the Sun, M2 is the mass of Proxima Centauri and r^2 is 15.2 light years =
1,363,263,031,001,664,000,000,000,000,000,000 metres. That's a mighty big
number to be dividing by to compute newtons. It didn't expect to have to do
it for you. You'll find the mass of the Sun in Kilograms if you search the
web and just double it for the mass of Proxima Centauri, that'll be close
enough.

In a talk by Ott, he comments on
| gravitational wave detectability
| (URL:http://jupiter.as.arizona.edu/~burrows/scidac/gr_talk101601.html,
| slide 33), comments that are based on Thorne (1997).
|
| He predicts that LIGO would be capable of detecting a Galactic
| supernova within the range of a few kiloparsec.

Ok, so where's the star that will go supernova within 3260 light years, and
what is the force of gravity it is exerting on us right now?
Hint:
r^2 = (c * 60*60*24*365.25 * 3260 )^2
= (c * 102877776000) ^2
= (300,000,000 * 102877776000) ^2
= 9.5254531152355584e+38 meters,
or circa 1,000,000 times greater than the r^2 I computed for Proxima
Centauri.


Your star going supernova can be up to 1000 solar masses if you like,
totally annihilate it, so the force you are planning to measure is 1/1000th
of the force you feel now from Proxima Centauri.

I don't think you have any concept of astronomical distances or what the
inverse square law means, and neither does Thorne.

Androcles.



|
| --
| Lt. Lazio, HTML police | e-mail:
| No means no, stop rape. | http://patriot.net/%7Ejlazio/
| sci.astro FAQ at http://sciastro.astronomy.net/sci.astro.html

In article , says...

In this first run no gravitational wave events were observed, but palpable
knowledge was gained as to what the sky should look like when viewed in the
form of gravity waves. So great is LIGO's sensitivity that it has been able
to set the best upper limit on the output of gravitational waves from three
of the four prime source categories. These four expected waveforms are as

I myself have established new upper limits on the presence of
interstellar alien beings today - there were none in my living room this
evening. With a modest grant (a few thousand dollars would suffice) I
believe I could extend this measurement to local hostelries and
restaurants over the coming months.

- Gerry Quinn