GR prediction for precession of perihelion of Mercury is not quite right
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From: Tom Roberts on 26 Jun 2010 12:25 Koobee Wublee wrote: > On Jun 25, 8:58 pm, Tom Roberts wrote: >> Before one knows whether or not this is significant, one must compare the >> discrepancy to the errorbars. The above-referenced article does not do that, and >> does not include the errorbars. >> >> So you must look up the errorbars in the literature before you can determine >> whether this is important or not. > > Not the errorbars again. Yes, OF COURSE "the errorbars again [sic]". Comparison between theory and experiment (measurement) ALWAYS requires errorbars. > What is the errorbar of the one due to other > solar bodies? They seem to be very big, no? I do not know, and neither does the author of the post to which I responded, or the author of the referenced article. THAT IS THE PROBLEM. Yes, I suspect there are contributions to the errorbars on the measurement that are comparable to the discrepancy. If, for instance, the errorbar turns out to be 3 arcsec/century, then the claim "the discrepancy is larger than the observational error" is correct, yet the discrepancy is not SIGNIFICANT, and thus is not important. For those of you who don't understand errorbars, let me explain. When making a measurement, there is ALWAYS some experimental error [#]. So we model the measurement process as yielding a distribution of values, with the actual value as the mean of the distribution, and the sigma of the distribution being the errorbar. It is observed that most measurement processes yield values that are approximately Gaussian distributed, so this is usually a good model. The best way to determine the errorbar is to measure it by taking multiple measurements and determining mean and sigma from the different measurements. With that in mind, only ~68% of the measurements will yield a value within one errorbar (sigma) of the actual value, and ~5% of the time the value will exceed twice the errorbar from the actual value. Assuming one has confidence in the value of the errorbar, physicists generally consider a discrepancy of 2 sigma or less to be not significant, a discrepancy between 3 and 4 sigma as inconclusive but provocative, and a discrepancy of 5 sigma or more as pretty definitive. [#] Error in the sense of discrepancy from the actual value, not in the sense of "mistake". This is standard usage. That said, I would not consider this discrepancy of 3.54 arcsec/century to be a problem unless the errorbar on the measurement is smaller than about 0.7 arcsec/century. If it's less than about 1.2 arcsec/century then it's probably worth revisiting. [Astronomers know this, and the fact that they are not revisiting this makes me infer that it is not a problem. But new techniques can often reduce the errorbar, and that can make it worth re-doing.] Tom Roberts
From: BURT on 26 Jun 2010 15:33 On Jun 26, 10:06 am, Surfer <n...(a)spam.net> wrote: > On Fri, 25 Jun 2010 11:34:48 -0700 (PDT), BURT <macromi...(a)yahoo.com> > wrote: > > > > > > >On Jun 25, 11:25 am, Surfer <n...(a)spam.net> wrote: > >> See:http://en.wikipedia.org/wiki/Tests_of_general_relativity#Perihelion_p... > > >> Amount: arcsec/Julian century > > >> 5603.24 Total predicted > >> 5599.7 Observed > > >> -3.54 Discrepancy > > >> The discrepancy is larger than the observational error > > >> In addition GR predicts that even a circular orbit with an > >> eccentricity of zero would precess--but such precession would be > >> unphysical. > > >Could it be a fall back rather than an advance? > > The total predicted precession is slightly too large. > A non-zero precession for a circular orbit also seems too large. > > Both problems would be fixed by a theory that appropriately predicts > less precession, with the amount tending to zero for a circular orbit. > > Interestingly, such predictions can be seen on page 70 in, > > Process Physics: From Information Theory to Quantum Space and Matter, > Cahill R.T. > Nova Science Pub., New York, 2005. > > So this could be the replacement theory for GR.- Hide quoted text - > > - Show quoted text - Time slowdown effects the metric of speed throuh the curve causing the elliptical fall short. THis is true of every orbit but too small to measure. Mitch Raemsch
From: oriel36 on 26 Jun 2010 15:44 On Jun 26, 5:25 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > That said, I would not consider this discrepancy of 3.54 arcsec/century to be a > problem unless the errorbar on the measurement is smaller than about 0.7 > arcsec/century. If it's less than about 1.2 arcsec/century then it's probably > worth revisiting. > > [Astronomers know this, and the fact that they are not revisiting > this makes me infer that it is not a problem. But new techniques > can often reduce the errorbar, and that can make it worth re-doing.] > > Tom Roberts Astronomers indeed !,in all the years on the newsgroups I have yet to meet one ! What would you like to know about orbital dynamics including the Earth's own motion ?,oh,that's right,you specialize in wordplays with others who know no better or inclined to this dull and dishonorable mathematical and non-geometric nonsense. I bet there is not one among you who can explain the seasons let alone figure out an Ra/Dec observation of the planet Mercury.
From: BURT on 26 Jun 2010 15:54 On Jun 26, 12:44 pm, oriel36 <kelleher.ger...(a)gmail.com> wrote: > On Jun 26, 5:25 pm, Tom Roberts <tjroberts...(a)sbcglobal.net> wrote: > > > That said, I would not consider this discrepancy of 3.54 arcsec/century to be a > > problem unless the errorbar on the measurement is smaller than about 0.7 > > arcsec/century. If it's less than about 1.2 arcsec/century then it's probably > > worth revisiting. > > > [Astronomers know this, and the fact that they are not revisiting > > this makes me infer that it is not a problem. But new techniques > > can often reduce the errorbar, and that can make it worth re-doing.] > > > Tom Roberts > > Astronomers indeed !,in all the years on the newsgroups I have yet to > meet one ! > > What would you like to know about orbital dynamics including the > Earth's own motion ?,oh,that's right,you specialize in wordplays with > others who know no better or inclined to this dull and dishonorable > mathematical and non-geometric nonsense. > > I bet there is not one among you who can explain the seasons let alone > figure out an Ra/Dec observation of the planet Mercury. Time slow effects elliptical orbit falling back by slowing the metric. Mitch Raemsch
From: Koobee Wublee on 26 Jun 2010 23:43
On Jun 26, 9:25 am, Tom Roberts wrote: > Koobee Wublee wrote: > > What is the errorbar of the one due to other > > solar bodies? They seem to be very big, no? > > I do not know, and neither does the author of the post to which I responded, or > the author of the referenced article. You got me. I don't know the error bar for the influence due to other solar bodies. I was hoping you might know and show so. So, you don't know either, and that does not bother you a bit. <shrug> > THAT IS THE PROBLEM. Yes, I suspect there > are contributions to the errorbars on the measurement that are comparable to the > discrepancy. If, for instance, the errorbar turns out to be 3 arcsec/century, > then the claim "the discrepancy is larger than the observational error" is > correct, yet the discrepancy is not SIGNIFICANT, and thus is not important. You don't see a problem because you are expecting and hoping for the validity in the Schwarzschild metric. That is not scientific. You are also guessing for a very small error bar. Have you noticed all the literatures so far presented to this newsgroup do not include this error bar? On top of that, the number 530 only has two significant digits. With no error bar associated, why are you assuming the error bar to be zero? > For those of you who don't understand errorbars... Let's lay out the issue at hand ignoring the nonsense due to the quadruple moment of the sun. Using the number of significant digits presented, we should have a good idea on how tight the error bar is. Observed = 5,599.7 +/- 0.? (no error bar) Equinox = 5,028.00 +/- 0.04 (super accurate) Perturbation = 530 +/- ?0 (implying very sloppy) So, it all depends on the error bar from the contribute due to other planets. With this argument, it does not bode well for the said 43" for the Schwarzschild metric's influence, don't you think? |