GR prediction for precession of perihelion of Mercury is not quite right
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From: kado on 2 Jul 2010 06:19 On Jul 2, 2:47 am, Jerry <Cephalobus_alie...(a)comcast.net> wrote: > snip > > ... It was Newcomb > who arrived at the modern value of 43 arcsec/century for the > anomalous precession of Mercury. > The reference you quote is in French, and unfortunately (for me) I don't understand French. So could you please post what the 'observed values' are? Also Newcomb's values would be greatly appreciated. D.Y.K.
From: Androcles on 2 Jul 2010 06:37 "Jerry" <Cephalobus_alienus(a)comcast.net> wrote in message news:08eee4f5-27d5-46be-b614-56749ebfffcf(a)f8g2000vbl.googlegroups.com... On Jul 2, 3:32 am, "k...(a)nventure.com" <k...(a)nventure.com> wrote: > I have always wondered how Joseph Le Verrier determined the > observed value of the advance of the perihelion of the obit > of Mercury to such precession that his mathematics of Newtonian > Mechanics results in an error of the tiny value 43 arc seconds > per century. He could not have observed this Natural Phenomenon > personally. > > Furthermore, the value of 43 arc seconds/century is the effect. > The accuracy of the 43 arc seconds is very dependent on the > causes, i.e., the accuracy of the so call the 'observed advance > of the perihelion of the orbit'/earth century, and Le Verrier's > math. > > Who the hell, or what team observed this for exactly one century, > and did anyone actually verify Le Verrier's math? Le Verrier had available to him well over a century (since 1631) of accurate timings of the transit of Mercury. This so-called "tiny value" of 43 arc seconds was throwing off his transit predictions by an hour. (Le Verrier actually calculated 38 arcsec per century.) http://articles.adsabs.harvard.edu/full/1859AnPar...5....1L Over the next several decades, Le Verrier's calculations were scrutinized by many people. By the time Asaph Hall and Simon Newcomb got around to studying the problem, the accumulated discrepancy in transit timings had reached about an hour and a half. Simon Newcomb had become director of the National Almanac Office in 1877, and as such had access to what was arguably the best-trained team of computers in the world under the management of George William Hill, to which he set the task of recalculating all the major astronomical constants. From 1896 on, Newcomb's values were the standard used by all ephemerides. It was Newcomb who arrived at the modern value of 43 arcsec/century for the anomalous precession of Mercury. Jerry ======================================== http://en.wikipedia.org/wiki/Euler's_three-body_problem There is no analytical solution to the general three body problem, let alone one with the Sun, Mercury, Venus, Earth and Jupiter. Of course Einstein, being god, could solve anything with his trusty slide rule where Euler, Lagrange, Liouville, Laplace, Jacobi, Darboux, Le Verrier, Velde, Hamilton, Poincar�, Birkhoff, and Whittaker failed. After all, a century is 415 orbits of the Sun by Mercury, so that's 415 * 360 degrees * 3600 arc seconds. = 537840000 arc seconds and 43/537840000 * 100 = 7.9949e-6 %, the kind of accuracy one expects from a genius like Einstein.
From: OwlHoot on 2 Jul 2010 06:55 On Jun 26, 5:23 am, Koobee Wublee <koobee.wub...(a)gmail.com> wrote: > On Jun 25, 8:58 pm, Tom Roberts wrote: > > > > > Surfer 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 > > > 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. What is the errorbar of the one due to other > solar bodies? They seem to be very big, no? <shrug> There's expected to be a slight discrepancy due to flattening of the Sun's core, on account of its quite rapid rotation. Since nobody yet knows the core's exact shape (although progress is being made by observations of surface vibrations), the same slight uncertainty is associated with the precession of Mercury's perihelion. Cheers John Ramsden
From: Jerry on 2 Jul 2010 07:32 On Jul 2, 5:19 am, "k...(a)nventure.com" <k...(a)nventure.com> wrote: > On Jul 2, 2:47 am, Jerry <Cephalobus_alie...(a)comcast.net> wrote: > > snip > > > ... It was Newcomb > > who arrived at the modern value of 43 arcsec/century for the > > anomalous precession of Mercury. > > The reference you quote is in French, and unfortunately > (for me) I don't understand French. > > So could you please post what the 'observed values' are? > Also Newcomb's values would be greatly appreciated. Classically, what was OBSERVED were transit timings. No matter what form of STATIC elliptical orbit one fit to Mercury's orbit, the discrepancy between the predicted and actual timings had reached an hour and a half by the end of the nineteenth century. The "observed values" of the transit timings after 1769, expressed in UTC, are readily available on the internet, although latitude and longitude information (very important for data analysis) seems somewhat harder to get. I don't have direct access to earlier observations, although references are made in Le Verrier's paper. I am wondering what you would intend to do with this information if I found it for you. Probably nothing? Jerry
From: Androcles on 2 Jul 2010 07:53
"OwlHoot" <ravensdean(a)googlemail.com> wrote in message news:2c3962a4-0f53-4925-9cdf-703af1b68ac7(a)a40g2000vbl.googlegroups.com... On Jun 26, 5:23 am, Koobee Wublee <koobee.wub...(a)gmail.com> wrote: > On Jun 25, 8:58 pm, Tom Roberts wrote: > > > > > Surfer 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 > > > 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. What is the errorbar of the one due to other > solar bodies? They seem to be very big, no? <shrug> There's expected to be a slight discrepancy due to flattening of the Sun's core, on account of its quite rapid rotation. Since nobody yet knows the core's exact shape (although progress is being made by observations of surface vibrations), the same slight uncertainty is associated with the precession of Mercury's perihelion. Cheers John Ramsden =========================================== Oh no, Einstein's super accurate trusty slide rule calculated EXACTLY where Mercury should be and we've had another century of observations since then, with all prophecies within the 415 orbits * 360 degrees * 3600 arc seconds = 537840000 arc seconds and 43/537840000 * 100 = 7.9949e-6 %, the kind of accuracy one expects from a genius like Einstein. |