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![]() "Henri Wilson" HW@.... wrote in message ... On 1 Apr 2007 07:57:46 -0700, "George Dishman" wrote: On 26 Mar, 00:56, HW@....(Henri Wilson) wrote: On Sun, 25 Mar 2007 00:31:31 -0000, "George Dishman" wrote: "Henri Wilson" HW@.... wrote in message .. . On Sat, 24 Mar 2007 13:45:26 -0000, "George Dishman" wrote: ... We know the pulsar produces pulses regularly every 2.285ms and it doesn't matter whether that is one or two or 27 per rotation, all that matters is that we can measure that they are emitted with a regularity almost as good as an atomic clock. I was under the imp[ression that the observed pulse was slowly changing too. Not to worry... Pulsars are normally slowing very slightly but it is _very_ gradual: http://outreach.atnf.csiro.au/educat...ryone/pulsars/ "For example, a pulsar called PSR J1603-7202 is known to have a period of 0.0148419520154668 seconds. However the periods of all radio pulsars are increasing extremely slowly. The period of PSR J1603-7202 increases by just 0.0000005 seconds every million years!" ..which is exactly what the BaTh predicts for a pulsar that is in a very large orbit. ..but it is also to be expected that they should be slowing as they lose energy. I see no problem there. "I expect" is not a mathematical prediction. Show the maths that gives you a figure of 500 ns per million years and I'll believe you. The VDoppler contribution is negligible...forget it. Nope, the simple indication from the phase is that it is completely dominant. If you want to forget it you have to show an alternative model, such as a higher eccentricity, that explains the phase. I'm not saying you can't, only that you cannot just wave your hands and pretend the phase data doesn't exist. If you read what I said in tyhe other message you will now know that the VDoppler effect doesn't exist...as I originally thought. We have since corrected that, your new numbers are realistic. The 'correction' is negligible. Fit your model to the observed data. I think you will find it is dominant. I don't really care about that, I want to know why they are delayed after they have been created. Are they delayed or advanced? Ballistic theory says they should be advanced but they are actually delayed. No. The BaTh should be in agreement with GR. It isn't, it ballistic theory predicts an advance, GR predicts a delay. All we have is a theory. It might be completely wrong. How do YOU explain the existence of pulses. The source emits a beam and spins like a lighthouse, you know that already. I don't know that any more. I dont think that explains what is observed. Do you think the beam is a narrowly focussed 'pencil'... or is it a plane? See the illustration here http://outreach.atnf.csiro.au/educat...ryone/pulsars/ In one of the papers I cited some time ago, there was a diagram shoing a cross-section where precession means we have stripes across the beam, like the scan lines of a TV. It's a pretty crappy article. It is not intended as technical. Quote: "The time between pulses, the period, is the time that it takes for the neutron star to rotate once. " Why aren't two pulses emitted per rotation? You are probably thinking of something like the animation on this page: http://science.nasa.gov/newhome/help...als/pulsar.htm In reality, it is probably more like the earlier static picture where the angle between the rotational and magnetic axes is smaller. The second beam is always pointing away from us. and: "Therefore the most likely explanation is that a pulsar is a neutron star that spins rapidly and emits radio waves along its magnetic axis. However, not all neutron stars are necessarily detectable as pulsars. The beams from some neutron stars may never pass the Earth and will therefore not be detected. Also, other neutron stars may have been pulsars in the past, but the process that causes the beam of radiation (which is not fully understood) may have turned off or is just too weak to be detected. " In other words, they don't know. In other words : a) the beams are thin so we expect to see only a fraction of the total number of pulsars. b) the energy to produce the beam runs out eventually. Both pretty obvious really. George, GR and the BaTh have the same equations as regards the slowing of light or the distortion of space to maintain its speed at c. No they don't Henry, nothing like it. George, the BaTh says light speed increases when light falls down a gravitty wwell just like anyhting else does. Yes, so the signals from the pulsar when it is on the far side of the companion should be accelerated towards us and then slowed to the original speed once it has passed the dwarf and is en route to us. That would produce an advance of the arrival time as we discussed some time ago. You appeared to agree the mechanism then so can you go back and have another read, I don't want to write all the same stuff again. GR says the same. No, it predicts a delay. GR effectively says the light s[p]eed remains constant and SPACE contracts to make that so. As the Pound- Rebka experiment showed, both approaches give the same answer. Pound-Rebka showed that processes seem to go slower when viewed from a higher potential. In GR the light seems to move slower when it is close to the companion hence it predicts a delay. But the companion is orbiting the star....not vice versa... Doesn't matter, only the relative speed matters. Move your finger in front of a light or move the light behind your finger and it gets blocked either way. The pulsar is barely moving. You have no model fit that predicts that, it is just handwaving and will turn out to be wrong when you do the work. We see a bright dot in the sky George. It could be anything. No Henry, it could not "be anything", it is a white dwarf because it has the spectrum that falls into that classification. Well if it can be positively identified let''s see its brightness curve. Do you think we can ask someone to try to measure it for us? Are you in touch with any astronomers? No. I suspect they will try to get some telescope time at some point but it will take its place in the priorities. Back to the abuse Henry? I'm just applying Kepler's laws and you say your program uses them so it should agree. Well you got the VDoppler business wrong for a start... Strange how you now agree with me. I agree ..but it is a negligible effect .....and not related to extinction. It is not _related_ to extinction but it allows us to put an upper limit on the distance over which extinction occurs. Fit your model and you'll see what I mean. Theories, theories...all based on wrong data... What is the truth? The truth is that the luminosity drops to near zero for 2 degrees of the orbit, that is the data and it is not an interpretation. eclipses CAN occur. And statistically we expect to see some. There is no reason to think this isn't one and the Shapiro delay matches. ...but there can also be eclipse-like dips in brightness curves caused purely by c+v. But the field rotates hundreds of times a second and the eclipse last 48 seconds every 2.4 hours (figures estimated from memory but right order of magnitude). But what is the form of the magnetic field? How can a magnetic field escape a neutron star when light cannot? Why do you say light cannot escape Henry, of course it escapes or we couldn't receive the pulses. I was under the impression that no light can escape from the neutron star itself. No, that only happens for black holes. In fact we see some pulsars in x-ray and gamma produced by infalling matter hitting the surface. An eclipse isn't hard to interpret. Oh but it is. The Bath expects many orbiting stars to appear as though they are eclipsing. All that is required is a moderately eccentric orbit and a periastron approx. nearest to the observer. Go on then, show how your program produces a drop to zero luninosity, or say by just five or six magnitudes, for just two degrees of the orbit with no variation at any other time. That is what the program is for isn't it? Sure. www.users.bigpond.com/hewn/narrow.jpg Nice. However, don't you get the same shape for the red velocity curve? I think you have used an extreme eccentricity and you are forgetting that the red velocity curve has to be a match to a Keplerian orbit of a much lower value. George |
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