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Groups > sci.physics.relativity > #385575 > unrolled thread
| Started by | Pentcho Valev <pvalev@yahoo.com> |
|---|---|
| First post | 2016-06-10 03:36 -0700 |
| Last post | 2016-06-19 15:03 -0700 |
| Articles | 16 on this page of 56 — 10 participants |
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The Nightmare of Einstein's General Relativity Pentcho Valev <pvalev@yahoo.com> - 2016-06-10 03:36 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-10 12:54 -0700
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-10 22:03 +0200
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-10 18:26 -0700
Re: The Nightmare of Einstein's General Relativity The Starmaker <starmaker@ix.netcom.com> - 2016-06-10 20:49 -0700
Re: The Nightmare of Einstein's General Relativity The Starmaker <starmaker@ix.netcom.com> - 2016-06-10 20:56 -0700
Re: The Nightmare of Einstein's General Relativity The Starmaker <starmaker@ix.netcom.com> - 2016-06-10 21:05 -0700
Re: The Nightmare of Einstein's General Relativity The Starmaker <starmaker@ix.netcom.com> - 2016-06-11 12:23 -0700
Re: The Nightmare of Einstein's General Relativity The Starmaker <starmaker@ix.netcom.com> - 2016-06-12 12:44 -0700
Re: The Nightmare of Einstein's General Relativity "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2016-06-10 21:20 -0700
Re: The Nightmare of Einstein's General Relativity The Starmaker <starmaker@ix.netcom.com> - 2016-06-11 00:12 -0700
Re: The Nightmare of Einstein's General Relativity "Ross A. Finlayson" <ross.finlayson@gmail.com> - 2016-06-11 11:04 -0700
Re: The Nightmare of Einstein's General Relativity Gary Harnagel <hitlong@yahoo.com> - 2016-06-11 05:09 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-11 10:56 -0700
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-11 20:30 +0200
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-11 09:47 +0200
Re: The Nightmare of Einstein's General Relativity Pentcho Valev <pvalev@yahoo.com> - 2016-06-11 02:28 -0700
Re: The Nightmare of Einstein's General Relativity dancouriann@gmail.com - 2016-06-11 09:55 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-12 12:53 -0700
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-12 22:15 +0200
Re: The Nightmare of Einstein's General Relativity Gary Harnagel <hitlong@yahoo.com> - 2016-06-12 15:37 -0700
Re: The Nightmare of Einstein's General Relativity mlwozniak@wp.pl - 2016-06-12 23:28 -0700
Re: The Nightmare of Einstein's General Relativity Gary Harnagel <hitlong@yahoo.com> - 2016-06-13 05:44 -0700
Re: The Nightmare of Einstein's General Relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2016-06-13 12:42 -0500
Re: The Nightmare of Einstein's General Relativity dancouriann@gmail.com - 2016-06-13 13:29 -0700
Re: The Nightmare of Einstein's General Relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2016-06-18 18:49 -0500
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-19 06:38 +0200
Re: The Nightmare of Einstein's General Relativity paparios <paparios@gmail.com> - 2016-06-19 07:13 -0700
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-19 20:34 +0200
Re: The Nightmare of Einstein's General Relativity paparios <paparios@gmail.com> - 2016-06-19 15:21 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-19 15:41 -0700
Re: The Nightmare of Einstein's General Relativity mlwozniak@wp.pl - 2016-06-19 23:35 -0700
Re: The Nightmare of Einstein's General Relativity paparios <paparios@gmail.com> - 2016-06-20 08:05 -0700
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-20 17:23 +0200
Re: The Nightmare of Einstein's General Relativity paparios <paparios@gmail.com> - 2016-06-20 08:53 -0700
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-20 18:32 +0200
Re: The Nightmare of Einstein's General Relativity paparios <paparios@gmail.com> - 2016-06-20 18:32 -0700
Re: The Nightmare of Einstein's General Relativity mlwozniak@wp.pl - 2016-06-20 23:15 -0700
Re: The Nightmare of Einstein's General Relativity paparios <paparios@gmail.com> - 2016-06-21 05:41 -0700
Re: The Nightmare of Einstein's General Relativity Tom Roberts <tjroberts137@sbcglobal.net> - 2016-06-19 12:18 -0500
Re: The Nightmare of Einstein's General Relativity Maciej Woźniak <mlwozniak@wp.pl> - 2016-06-19 20:40 +0200
Re: The Nightmare of Einstein's General Relativity dancouriann@gmail.com - 2016-06-19 12:51 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-19 15:39 -0700
Re: The Nightmare of Einstein's General Relativity dancouriann@gmail.com - 2016-06-19 20:34 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-20 00:13 -0700
Re: The Nightmare of Einstein's General Relativity dancouriann@gmail.com - 2016-06-20 08:15 -0700
Re: The Nightmare of Einstein's General Relativity Pentcho Valev <pvalev@yahoo.com> - 2016-06-13 03:41 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-13 11:34 -0700
Re: The Nightmare of Einstein's General Relativity mlwozniak@wp.pl - 2016-06-13 23:08 -0700
Re: The Nightmare of Einstein's General Relativity Gary Harnagel <hitlong@yahoo.com> - 2016-06-14 07:15 -0700
Re: The Nightmare of Einstein's General Relativity Pentcho Valev <pvalev@yahoo.com> - 2016-06-17 05:05 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-17 09:46 -0700
Re: The Nightmare of Einstein's General Relativity Pentcho Valev <pvalev@yahoo.com> - 2016-06-18 12:34 -0700
Re: The Nightmare of Einstein's General Relativity Gary Harnagel <hitlong@yahoo.com> - 2016-06-18 13:30 -0700
Re: The Nightmare of Einstein's General Relativity JanPB <filmart@gmail.com> - 2016-06-18 14:53 -0700
Re: The Nightmare of Einstein's General Relativity Pentcho Valev <pvalev@yahoo.com> - 2016-06-19 15:03 -0700
Page 3 of 3 — ← Prev page 1 2 [3]
| From | Maciej Woźniak <mlwozniak@wp.pl> |
|---|---|
| Date | 2016-06-19 20:40 +0200 |
| Message-ID | <nk6ovs$cl7$1@node1.news.atman.pl> |
| In reply to | #386231 |
Użytkownik "Tom Roberts" napisał w wiadomości grup dyskusyjnych:07idnYpfS4R4TvvKnZ2dnUU7_81g4p2d@giganews.com... On 6/18/16 6/18/16 11:38 PM, Maciej Woźniak wrote: > Użytkownik "Tom Roberts" napisał w wiadomości grup > dyskusyjnych:iu-dnckbLrBjQPjKnZ2dnUU7_83NnZ2d@giganews.com... > |I repeat: "Time dilation" is NOT "different effective time standards". > The "time > |standard" we use comes from ISO, and the second is defined as > 9,192,631,770 > |cycles of the hyperfine transition of the ground state of Cs133. > > What you wrote is not any standard, check it at GPS. |NONSENSE! Your fantasies do not correspond to the real world, and your ignorance |is showing: Just READ the GPS documents, and you'll find the GPS uses this standard. A lie, as expected from relativistic trash. The clocks of GPS are corrected, comparing to your moronic pseudostandard, and you, yourself, admitted it here many times. Do you want quotings?
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| From | dancouriann@gmail.com |
|---|---|
| Date | 2016-06-19 12:51 -0700 |
| Message-ID | <8e8e792f-574a-464b-847c-2326a0635020@googlegroups.com> |
| In reply to | #386172 |
On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: >> The premise of Argument 1 is Newtonian physics in flat space with absolute >> time, rejecting both special and general relativity. >Nobody actually said so until you did here. The original post said “You do not need general relativity to derive the correct prediction for the gravitational redshift. A combination of Newtonian gravity, a particle theory of light, and the weak equivalence principle (gravitating mass equals inertial mass) suffices...” On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > If you want to discuss operational quantities, you must use CLOCKS, > not some arbitrary coordinates... Schwarzschild coordinates (and isotropic coordinates, and etc.) have perfectly well-defined operational meanings. If they didn’t, they would be meaningless. Also, they are far from arbitrary: The Schwarzschild coordinate time is the essentially unique time coordinate (up to scale factors) in a spherically symmetrical gravitational field such that the metric coefficients are independent of the time coordinate (i.e., they are a Killing field). This is what makes them eminently suitable for describing phenomena, including the behavior of physical clocks, the deflection of light, etc. On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > But the Schw. time coordinate does NOT agree with real clocks > anywhere except at spatial infinity. And it CERTAINLY is not proper > time for "stationary clocks at different gravitational potentials". I don’t think you read what I wrote: Relative to an essentially static time coordinate (such as the Schwarzschild time coordinate) in a region with a stationary gravitational field, the rate of proper time for stationary clocks at different gravitational potentials is different, hence the difference in frequency between emission and reception of a steady sequence of objects passing from one stationary clock to the other. On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > Operationally we do observe "time dilation" in all its forms. Indeed, but we cannot observe the time dilation factors by merely measuring the time interval dtau between ticks and comparing with the value specified by the manufacturer, because the gravitational field affects our time standards in exactly the same way as it affects the clock being studied. That is, if our standard clock says that a certain physical process takes 1 sec at rest in the absence of gravitation, then it will also tell us that it takes 1 sec in the presence of gravitation, both standard clock and process being affected by the field in the same way. However, we can compare time dilation factors at two different points in a field. For instance, suppose that at point 1 we observe the light coming from a particular atomic transition at point 2. If points 1 and 2 are at rest in a stationary gravitational field, then the time taken for a wave crest to travel from 2 to 1 will be constant, and therefore the coordinate time between arrival at point 1 of successive crests will equal the time dt2 = dtau/sqrt(-g_tt(x2)) between their departures at point 2. If the same atomic transition occurs at point 1, the coordinate time between crests of the light waves observed at point 1 will be dt1 = dtau/sqrt(-g_tt(x1)). On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > You don't want discussions of geometry, but it is difficult > to reconcile the observations without it I didn’t say we can’t discuss geometry, I said that it’s usually not helpful to talk in terms of “geometric effects”, because this introduces philosophical issues about interpretational aspects of theories, related to the age-old question of whether geometry is efficacious or merely descriptive. In foundational discussions it’s best to focus on operationally well-defined statements. On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > I know of no successful model for this except geometrical > curvature in spacetime. There are other interpretational models of general relativity, but of course any well-defined statement must give the same answer, regardless of the interpretation. Regardless, I don’t think the question at issue here (whether Newtonian theory predicts gravitational redshift) hinges on the interpretational aspects of general relativity. On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > But YOU are not using an "operational sense" -- you refer to the > "Schwarzschild coordinates", not CLOCKS, so your discussion is > not operational at all. Again, Schwarzschild coordinates have a perfectly well-defined operational meaning (metric coefficients independent of t, area of surface of constant radial coordinate is 4 pi r^2). So do isotropic coordinates (which use the Schwarzschild time coordinate), used extensively by astrophysicists because of their conformal property. If these coordinate systems had no operational meaning, they would be meaningless. On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > One essential aspect of GR is to NOT use coordinate-dependent > quantities when discussing phenomena... That’s not an aspect of general relativity. One obviously must exercise care in applying coordinates, with a clear understanding of their operational significance, but they are indispensible for nearly every non-trivial calculation. On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: >> Slow-moving particles generally still accelerate toward a massive body, > Reasonable authors ALWAYS specify which they mean. I've been perfectly explicit in defining exactly what I’m referring to when I say that the speed of light in terms of the operationally meaningful Schwarzchild coordinates is less as the light approaches the gravitating body. You actually responded to this (above) by saying “Yes”, so you not only understood it, your agreed with it. In view of that, I don’t think you can legitimately accuse me of not specifying my meaning – nor of saying anything untrue. Your complaint seems to be that although I have explicitly made a true statement about the speed of light in terms of a specified system of global static coordinates, this statement has no physical significance. But that’s obviously not true. For example, a plane wave of light from a distant star passing near the Sun will be deflected in terms of static isotropic coordinates, but this is true if and only if, in terms of these coordinates, the speed of the wave front is lower near the Sun, so that the wave front tilts. I don’t know of any derivation of the angular deflection of light in a gravitational field that doesn’t make use of coordinates in which the speed of light is lower near the gravitating body. Nor do I know of any reputable scientist who would agree with you that the deflection of light in a gravitational field "has nothing whatsoever to do with the behavior of light" in a gravitational field.
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| From | JanPB <filmart@gmail.com> |
|---|---|
| Date | 2016-06-19 15:39 -0700 |
| Message-ID | <de4ad39f-2c82-4aa2-a2d7-7a46c0bafed1@googlegroups.com> |
| In reply to | #386172 |
On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > On 6/13/16 6/13/16 3:29 PM, dancouriann@gmail.com wrote: > > > > No one disputes that, in > > terms of Schwarzschild coordinates (the more or less unique static time > > coordinate in a spherical field), the radial speed of light is lower near a > > massive body, so the Schwarzschild coordinate velocity of a pulse of light > > approaching a massive body decreases. > > Yes. But this has NOTHING WHATSOEVER to do with the behavior of light, it is > merely the behavior OF THE COORDINATES. You seem completely unaware of this. This was in fact one of the early confusions regarding the understanding of GR. People assumed at first that the decreasing Schwarzschild coordinate speed actually meant decreasing speed and concluded light would stop and circle around asymptotically approaching the Schwarzschild radius. This "phenomenon" was referred to as "the magic ring". The story of clearing up this confusion is interesting, you can read it on Wikipedia: https://en.wikipedia.org/wiki/Gullstrand–Painlevé_coordinates https://en.wikipedia.org/wiki/Eddington%E2%80%93Finkelstein_coordinates Summary: * Gullstrand and Painlevé around 1921/1922 came up with what they thought was another solution to the spherically symmetric case. Einstein was unimpressed saying that the coordinates themselves have no meaning. * In 1933 Lemaître noticed the G-P solution was a coordinate transformation of the Schwarzschild one. * I don't know who and when at this point noticed that Lemaître's remark implied the horizon was not singular. * At that point someone did the obvious calculation of computing the actual speed of infalling material objects using proper time and concluded that the "magic ring" was a misundesrtanding and an error. * I didn't know that (according to Wikipedia above) neither Eddington nor Finkelstein wrote down the metric that bears their name. Apparently it was Roger Penrose who did it first in 1965 but _thought_ it was Finkelstein in 1958. The same misattribution has been propagated a bit later by the enormously influential MTW. Not sure how much of this is true, sounds quite plausible. -- Jan
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| From | dancouriann@gmail.com |
|---|---|
| Date | 2016-06-19 20:34 -0700 |
| Message-ID | <faedfc42-cd20-4a2d-9054-4ba276cfa9c7@googlegroups.com> |
| In reply to | #386251 |
On Sunday, June 19, 2016 at 3:39:52 PM UTC-7, JanPB wrote: On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > On 6/13/16 6/13/16 3:29 PM, danco...@gmail.com wrote: >>> No one disputes that, in terms of Schwarzschild coordinates >>> (the more or less unique static time coordinate in a spherical >>> field), the radial speed of light is lower near a massive body, >>> so the Schwarzschild coordinate velocity of a pulse of light >>> approaching a massive body decreases. >> Yes. But this has NOTHING WHATSOEVER to do with the behavior >> of light, it is merely the behavior OF THE COORDINATES. > This was in fact one of the early confusions regarding the > understanding of GR. The historical accounts you cited pertain to confusion as to whether or not there is a physical singularity in the manifold at the Schwarzschild radius, or whether it is just a coordinate singularity. That is not what’s being discussed here. On Sunday, June 19, 2016 at 3:39:52 PM UTC-7, JanPB wrote: > People assumed at first that the decreasing Schwarzschild > coordinate speed actually meant decreasing speed... The assertion under discussion here (see above) is that decreasing Schwarzschild coordinate speed actually means decreasing Schwarzschild coordinate speed. This is not an assumption, it is a tautology. On the other hand, the claim that this has “nothing whatsoever to do with the behavior of light” is obviously false, since it relies on the fact that light follows null geodesics. Your second clause refers to “speed” without specification, so it’s meaningless. Perhaps you meant to refer to the speed of light in terms of free-falling inertial coordinates in any particular infinitesimal region, in terms of which the speed is always c. > and concluded light would stop and circle around asymptotically > approaching the Schwarzschild radius. I have never heard of this. Are you saying that someone once believed that radially inward rays of light would somehow be deflected into a circular orbit as they approach the Schwarzschild radius? This is bizarre. > This "phenomenon" was referred to as "the magic ring". I have never heard of this either. As far as I can tell, the words “magic ring” do not appear in either of your links. Could you cite a reference for this “magic ring” where light was thought to “stop and circle around asymptotically approaching the Schwarzschild radius”? (Actually there exist null trajectories that do something like this, except they asymptotically approach the light orbit radius at r = 3m, rather than the Schwarzschild radius at r = 2m, but of course they were never radial paths, and they eventually either spiral back out our else spiral in.)
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| From | JanPB <filmart@gmail.com> |
|---|---|
| Date | 2016-06-20 00:13 -0700 |
| Message-ID | <8f33e4f8-2620-49af-886b-7e69623ead30@googlegroups.com> |
| In reply to | #386262 |
On Sunday, June 19, 2016 at 8:34:35 PM UTC-7, danco...@gmail.com wrote: > On Sunday, June 19, 2016 at 3:39:52 PM UTC-7, JanPB wrote: > On Saturday, June 18, 2016 at 4:49:24 PM UTC-7, tjrob137 wrote: > > On 6/13/16 6/13/16 3:29 PM, danco...@gmail.com wrote: > >>> No one disputes that, in terms of Schwarzschild coordinates > >>> (the more or less unique static time coordinate in a spherical > >>> field), the radial speed of light is lower near a massive body, > >>> so the Schwarzschild coordinate velocity of a pulse of light > >>> approaching a massive body decreases. > >> Yes. But this has NOTHING WHATSOEVER to do with the behavior > >> of light, it is merely the behavior OF THE COORDINATES. > > This was in fact one of the early confusions regarding the > > understanding of GR. > > The historical accounts you cited pertain to confusion as to whether or not there is a physical singularity in the manifold at the Schwarzschild radius, or whether it is just a coordinate singularity. That is not what’s being discussed here. I was referring to the confusion regarding the infalling null or timelike Schwarzschild geodesics: they seem to slow down the closer they get to the horizon. The timelike ones will have the coordinate speed decreasing to zero. > On Sunday, June 19, 2016 at 3:39:52 PM UTC-7, JanPB wrote: > > People assumed at first that the decreasing Schwarzschild > > coordinate speed actually meant decreasing speed... > > The assertion under discussion here (see above) is that decreasing Schwarzschild coordinate speed actually means decreasing Schwarzschild coordinate speed. This is not an assumption, it is a tautology. Sure. If that's all you are saying - fine. For some reason I thought you were arguing this meant infalling objects would never cross the horizon. > On the other hand, the claim that this has “nothing whatsoever to do with the behavior of light” is obviously false, since it relies on the fact that light follows null geodesics. Your second clause refers to “speed” without specification, so it’s meaningless. Perhaps you meant to refer to the speed of light in terms of free-falling inertial coordinates in any particular infinitesimal region, in terms of which the speed is always c. > > > and concluded light would stop and circle around asymptotically > > approaching the Schwarzschild radius. > > I have never heard of this. Are you saying that someone once believed that radially inward rays of light would somehow be deflected into a circular orbit as they approach the Schwarzschild radius? This is bizarre. A light ray slightly off-inward. > > This "phenomenon" was referred to as "the magic ring". > > I have never heard of this either. As far as I can tell, the words “magic ring” do not appear in either of your links. Could you cite a reference for this “magic ring” where light was thought to “stop and circle around asymptotically approaching the Schwarzschild radius”? I think it's in Møller's GR book but it may have been some GR history paper. I'll try to find it. > (Actually there exist null trajectories that do something like this, except they asymptotically approach the light orbit radius at r = 3m, rather than the Schwarzschild radius at r = 2m, but of course they were never radial paths, and they eventually either spiral back out our else spiral in.) Yes. -- Jan
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| From | dancouriann@gmail.com |
|---|---|
| Date | 2016-06-20 08:15 -0700 |
| Message-ID | <8ff6e137-a99f-48db-b330-af6b928f4be7@googlegroups.com> |
| In reply to | #386274 |
On Monday, June 20, 2016 at 12:13:44 AM UTC-7, JanPB wrote: > I was referring to the confusion regarding the infalling > null or timelike Schwarzschild geodesics: they seem to > slow down the closer they get to the horizon. The timelike > ones will have the coordinate speed decreasing to zero. The null ones too. On Monday, June 20, 2016 at 12:13:44 AM UTC-7, JanPB wrote: >> The assertion under discussion here (see above) is >> that decreasing Schwarzschild coordinate speed >> actually means decreasing Schwarzschild coordinate >> speed. This is not an assumption, it is a tautology. > > Sure. If that's all you are saying - fine. For > some reason I thought you were arguing this meant > infalling objects would never cross the horizon. That's interesting. On Monday, June 20, 2016 at 12:13:44 AM UTC-7, JanPB wrote: >>> and concluded light would stop and circle around asymptotically >>> approaching the Schwarzschild radius. >> I have never heard of this. Are you saying that someone >> once believed that radially inward rays of light would >> somehow be deflected into a circular orbit as they >> approach the Schwarzschild radius? This is bizarre. > A light ray slightly off-inward. Well, it actually IS possible for a non-radial ray to spiral inward (to a non-rotating black hole), although the asymptotic radius is at r = 3m rather than the Schwarzschild radius at r = 2m, and it is unstable so it would eventually either spiral back out or spiral in. But surely this is separate from the historical discussion of whether or not their was a genuine singularity at r = 2m. >>> This "phenomenon" was referred to as "the magic ring". >> I have never heard of this either. As far as I can tell, >> the words “magic ring” do not appear in either of your links. >> Could you cite a reference for this “magic ring” where light >> was thought to “stop and circle around asymptotically >> approaching the Schwarzschild radius”? > > I think it's in Møller's GR book but it may have been some > GR history paper. I'll try to find it. I googled it, and the only hits are for a statement from Kerr regarding his solution for a rotating back hole in the 1960s, which includes some weird regions where strange things happen. He apparently once said something like "If you pass through the magic ring - presto! - you are in a different universe". But this is unrelated to the early discussions about whether there is a genuine singularity at r=2m of the Schwarzschild solution. I did find one other indirect reference, a time table of the history of black holes, and at one point on the chart is says parenthetically "(magic ring, Eddington)". So I suppose it's possible that Eddington once used the phrase, but I haven't found it.
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| From | Pentcho Valev <pvalev@yahoo.com> |
|---|---|
| Date | 2016-06-13 03:41 -0700 |
| Message-ID | <26bfef95-2d97-4be8-bf8f-068594aea5f8@googlegroups.com> |
| In reply to | #385649 |
According to Einstein's general relativity, the speed of light falling towards the source of gravity idiotically DECREASES - in the gravitational field of the Earth the acceleration of falling photons is NEGATIVE, -2g. In my previous posting I showed that the idiocy was unavoidable - the acceleration "-2g" can be regarded as a parameter, or a fudge factor, introduced into the "theory" in order to make it compatible with gravitational time dilation, a miraculous effect Einstein fabricated in 1911:
https://en.wikipedia.org/wiki/Fudge_factor
"A fudge factor is an ad hoc quantity introduced into a calculation, formula or model in order to make it fit observations or expectations. Examples include Einstein's Cosmological Constant, dark energy, dark matter and inflation. (...) In theoretical physics, when Einstein originally tried to produce a general theory of relativity, he found that the theory seemed to predict the gravitational collapse of the universe: it seemed that the universe should either be expanding or collapsing, and to produce a model in which the universe was static and stable (which seemed to Einstein at the time to be the "proper" result), he introduced an expansionist variable (called the Cosmological Constant), whose sole purpose was to cancel out the cumulative effects of gravitation."
The above definition draws the attention to another fudge factor, Einstein's cosmological constant:
http://www.nybooks.com/daily/2016/01/09/einstein-right-and-wrong/
"In 1917 Einstein published a paper on the application of the theory of relativity to the universe at large—cosmology. He had decided that the universe was stationary—neither expanding nor contracting—so he added a term, the cosmological constant, to his original equations with a value of the constant, the Λ in the above equation, chosen to guarantee this. He abandoned this once it was shown in the 1920s by Edwin Hubble that the universe was actually expanding. Now it has been shown that the universe is expanding at an accelerating rate—so the cosmological term is given a new value, the dark energy, now adjusted to produce the acceleration."
The making of Einstein's general relativity (as well as its subsequent development) consisted in endlessly introducing, withdrawing and changing equations and parameters (fudge factors) "in order to make it fit observations or expectations". Needless to say, this is not a deductive theory and even not a theory at all. Unlike special relativity (which is deductive), general relativity is an empirical model:
http://collum.chem.cornell.edu/documents/Intro_Curve_Fitting.pdf
"The objective of curve fitting is to theoretically describe experimental data with a model (function or equation) and to find the parameters associated with this model. Models of primary importance to us are mechanistic models. Mechanistic models are specifically formulated to provide insight into a chemical, biological, or physical process that is thought to govern the phenomenon under study. Parameters derived from mechanistic models are quantitative estimates of real system properties (rate constants, dissociation constants, catalytic velocities etc.). It is important to distinguish mechanistic models from empirical models that are mathematical functions formulated to fit a particular curve but whose parameters do not necessarily correspond to a biological, chemical or physical property."
Note that the parameters of the empirical model, e.g. the acceleration "-2g" and the cosmological constant, "do not necessarily correspond to a biological, chemical or physical property".
Here Michel Janssen describes endless empirical fudging and fitting until "excellent agreement with observation" was reached:
https://netfiles.umn.edu/users/janss011/home%20page/EBms.pdf
Michel Janssen: "But - as we know from a letter to his friend Conrad Habicht of December 24, 1907 - one of the goals that Einstein set himself early on, was to use his new theory of gravity, whatever it might turn out to be, to explain the discrepancy between the observed motion of the perihelion of the planet Mercury and the motion predicted on the basis of Newtonian gravitational theory. (...) The Einstein-Grossmann theory - also known as the "Entwurf" ("outline") theory after the title of Einstein and Grossmann's paper - is, in fact, already very close to the version of general relativity published in November 1915 and constitutes an enormous advance over Einstein's first attempt at a generalized theory of relativity and theory of gravitation published in 1912. The crucial breakthrough had been that Einstein had recognized that the gravitational field - or, as we would now say, the inertio-gravitational field - should not be described by a variable speed of light as he had attempted in 1912, but by the so-called metric tensor field. The metric tensor is a mathematical object of 16 components, 10 of which independent, that characterizes the geometry of space and time. In this way, gravity is no longer a force in space and time, but part of the fabric of space and time itself: gravity is part of the inertio-gravitational field. Einstein had turned to Grossmann for help with the difficult and unfamiliar mathematics needed to formulate a theory along these lines. (...) Einstein did not give up the Einstein-Grossmann theory once he had established that it could not fully explain the Mercury anomaly. He continued to work on the theory and never even mentioned the disappointing result of his work with Besso in print. So Einstein did not do what the influential philosopher Sir Karl Popper claimed all good scientists do: once they have found an empirical refutation of their theory, they abandon that theory and go back to the drawing board. (...) On November 4, 1915, he presented a paper to the Berlin Academy officially retracting the Einstein-Grossmann equations and replacing them with new ones. On November 11, a short addendum to this paper followed, once again changing his field equations. A week later, on November 18, Einstein presented the paper containing his celebrated explanation of the perihelion motion of Mercury on the basis of this new theory. Another week later he changed the field equations once more. These are the equations still used today. This last change did not affect the result for the perihelion of Mercury. Besso is not acknowledged in Einstein's paper on the perihelion problem. Apparently, Besso's help with this technical problem had not been as valuable to Einstein as his role as sounding board that had earned Besso the famous acknowledgment in the special relativity paper of 1905. Still, an acknowledgment would have been appropriate. After all, what Einstein had done that week in November, was simply to redo the calculation he had done with Besso in June 1913, using his new field equations instead of the Einstein-Grossmann equations. It is not hard to imagine Einstein's excitement when he inserted the numbers for Mercury into the new expression he found and the result was 43", in excellent agreement with observation."
Pentcho Valev
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| From | JanPB <filmart@gmail.com> |
|---|---|
| Date | 2016-06-13 11:34 -0700 |
| Message-ID | <38537184-b99d-42a1-ab68-a3b2c13a0af7@googlegroups.com> |
| In reply to | #385775 |
On Monday, June 13, 2016 at 3:41:46 AM UTC-7, Pentcho Valev wrote: > According to Einstein's general relativity, the speed of light falling towards the source of gravity idiotically DECREASES - in the gravitational field of the Earth the acceleration of falling photons is NEGATIVE, -2g. In my previous posting I showed that the idiocy was unavoidable - the acceleration "-2g" can be regarded as a parameter, or a fudge factor, introduced into the "theory" in order to make it compatible with gravitational time dilation, a miraculous effect Einstein fabricated in 1911: All of the above is false or misleading at best. Sorry. -- Jan
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| From | mlwozniak@wp.pl |
|---|---|
| Date | 2016-06-13 23:08 -0700 |
| Message-ID | <4ecc439a-f9b1-4bb4-a7e6-26b3c15ff516@googlegroups.com> |
| In reply to | #385808 |
W dniu poniedziałek, 13 czerwca 2016 20:34:32 UTC+2 użytkownik JanPB napisał: > All of the above is false or misleading at best. Sorry. Gobledygook!
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| From | Gary Harnagel <hitlong@yahoo.com> |
|---|---|
| Date | 2016-06-14 07:15 -0700 |
| Message-ID | <fce972cf-bee6-4a06-ad41-2ca58d45c79a@googlegroups.com> |
| In reply to | #385837 |
On Tuesday, June 14, 2016 at 12:08:41 AM UTC-6, mlwo...@wp.pl wrote: > > W dniu poniedziałek, 13 czerwca 2016 20:34:32 UTC+2 użytkownik JanPB napisał: > > > > All of the above is false or misleading at best. Sorry. > > Gobledygook! Turkey!
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| From | Pentcho Valev <pvalev@yahoo.com> |
|---|---|
| Date | 2016-06-17 05:05 -0700 |
| Message-ID | <62c64a16-b1b9-467e-8ca9-2f40dbd32ca5@googlegroups.com> |
| In reply to | #385775 |
Einstein informs the gullible world that his approach was deductive: https://www.marxists.org/reference/archive/einstein/works/1910s/relative/ap03.htm Albert Einstein: "From a systematic theoretical point of view, we may imagine the process of evolution of an empirical science to be a continuous process of induction. Theories are evolved and are expressed in short compass as statements of a large number of individual observations in the form of empirical laws, from which the general laws can be ascertained by comparison. Regarded in this way, the development of a science bears some resemblance to the compilation of a classified catalogue. It is, as it were, a purely empirical enterprise. But this point of view by no means embraces the whole of the actual process ; for it slurs over the important part played by intuition and deductive thought in the development of an exact science. As soon as a science has emerged from its initial stages, theoretical advances are no longer achieved merely by a process of arrangement. Guided by empirical data, the investigator rather develops a system of thought which, in general, is built up logically from a small number of fundamental assumptions, the so-called axioms." Einstein is blatantly lying of course - his general relativity was the result of purely empirical gropings (changing and fudging equations until maximum fit with known in advance results and pet assumptions is reached): https://netfiles.umn.edu/users/janss011/home%20page/EBms.pdf Michel Janssen: "So Einstein did not do what the influential philosopher Sir Karl Popper claimed all good scientists do: once they have found an empirical refutation of their theory, they abandon that theory and go back to the drawing board. [...] On November 4, 1915, he presented a paper to the Berlin Academy officially retracting the Einstein-Grossmann equations and replacing them with new ones. On November 11, a short addendum to this paper followed, once again changing his field equations. A week later, on November 18, Einstein presented the paper containing his celebrated explanation of the perihelion motion of Mercury on the basis of this new theory. Another week later he changed the field equations once more. These are the equations still used today. This last change did not affect the result for the perihelion of Mercury. Besso is not acknowledged in Einstein's paper on the perihelion problem. Apparently, Besso's help with this technical problem had not been as valuable to Einstein as his role as sounding board that had earned Besso the famous acknowledgment in the special relativity paper of 1905. Still, an acknowledgment would have been appropriate. After all, what Einstein had done that week in November, was simply to redo the calculation he had done with Besso in June 1913, using his new field equations instead of the Einstein-Grossmann equations. It is not hard to imagine Einstein's excitement when he inserted the numbers for Mercury into the new expression he found and the result was 43", in excellent agreement with observation." http://discovermagazine.com/2004/sep/the-masters-mistakes/ "In 1916 Einstein found what he considered a glitch in his new theory of general relativity. His equations showed that the contents of the universe should be moving— either expanding or contracting. But at the time, the universe seemed the very definition of stasis. All the data, facts, and phenomena known in the early 1900s said that the Milky Way was the cosmos itself and that its stars moved slowly, if at all. Einstein had presented the definitive version of the general theory of relativity to the Prussian Academy of Sciences the previous year, and he was not inclined to retract it. So he invented a fudge factor, called lambda, that could function mathematically to hold the universe at a standstill. [...] Lambda, also known as the cosmological constant, has come in handy of late." http://www.amazon.com/Magnificent-Universe-Ken-Croswell/dp/0684845946 Ken Croswell, Magnificent Universe, p. 179: "Ever since, the cosmological constant has lived in infamy, a fudge factor concocted merely to make theory agree with observation." Pentcho Valev
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| From | JanPB <filmart@gmail.com> |
|---|---|
| Date | 2016-06-17 09:46 -0700 |
| Message-ID | <fc9cc9a6-ff61-4e56-a6ce-95f321b784fb@googlegroups.com> |
| In reply to | #386042 |
On Friday, June 17, 2016 at 5:06:00 AM UTC-7, Pentcho Valev wrote: > Einstein informs the gullible world that his approach was deductive: > > https://www.marxists.org/reference/archive/einstein/works/1910s/relative/ap03.htm > Albert Einstein: "From a systematic theoretical point of view, we may imagine the process of evolution of an empirical science to be a continuous process of induction. Theories are evolved and are expressed in short compass as statements of a large number of individual observations in the form of empirical laws, from which the general laws can be ascertained by comparison. Regarded in this way, the development of a science bears some resemblance to the compilation of a classified catalogue. It is, as it were, a purely empirical enterprise. But this point of view by no means embraces the whole of the actual process ; for it slurs over the important part played by intuition and deductive thought in the development of an exact science. As soon as a science has emerged from its initial stages, theoretical advances are no longer achieved merely by a process of arrangement. Guided by empirical data, the investigator rather develops a system of thought which, in general, is built up logically from a small number of fundamental assumptions, the so-called axioms." > > Einstein is blatantly lying of course - his general relativity was the result of purely empirical gropings (changing and fudging equations until maximum fit with known in advance results and pet assumptions is reached): Ah, so you don't know general relativity. Why am I not surprised. So no, the answer is that GR is not a result of "fudging" in the sense you think. There was of course groping for the solution but this is true of virtually all theories in physics. OTOH the "fudging" you have in mind is absent from GR because it's a theory with very few tuning parameters. All Pentcho's posts can be safely ignored, he is another guy with an agenda, not interested in science at all. -- Jan
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| From | Pentcho Valev <pvalev@yahoo.com> |
|---|---|
| Date | 2016-06-18 12:34 -0700 |
| Message-ID | <e6126e80-382d-47f2-a2e7-e15aa3a60c46@googlegroups.com> |
| In reply to | #386042 |
Einstein's idiotic prediction that the speed of light falling towards the source of gravity DECREASES is a nightmare only for ordinary Einsteinians; the subtlest practitioners of doublethink in Einsteiniana teach it with ease: https://www.youtube.com/watch?v=jc-QqYCSzF4 At the Annual Philosophy of Physics Conference, Gravity and Geometry: Centenary Perspectives on General Relativity, John Norton presented this lecture, entitled, "Einstein’s Discovery of the General Theory of Relativity". John Norton (13:14): "The deeper you are in the [gravitational] field, linearly, the slower the light gets." http://ebooks.adelaide.edu.au/o/orwell/george/o79n/chapter2.9.html "Doublethink means the power of holding two contradictory beliefs in one's mind simultaneously, and accepting both of them. The Party intellectual knows in which direction his memories must be altered; he therefore knows that he is playing tricks with reality; but by the exercise of doublethink he also satisfies himself that reality is not violated. The process has to be conscious, or it would not be carried out with sufficient precision, but it also has to be unconscious, or it would bring with it a feeling of falsity and hence of guilt. Doublethink lies at the very heart of Ingsoc, since the essential act of the Party is to use conscious deception while retaining the firmness of purpose that goes with complete honesty. To tell deliberate lies while genuinely believing in them, to forget any fact that has become inconvenient, and then, when it becomes necessary again, to draw it back from oblivion for just so long as it is needed, to deny the existence of objective reality and all the while to take account of the reality which one denies - all this is indispensably necessary. [...] It need hardly be said that the subtlest practitioners of doublethink are those who invented doublethink and know that it is a vast system of mental cheating. In our society, those who have the best knowledge of what is happening are also those who are furthest from seeing the world as it is. In general, the greater the understanding, the greater the delusion ; the more intelligent, the less sane." Pentcho Valev
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| From | Gary Harnagel <hitlong@yahoo.com> |
|---|---|
| Date | 2016-06-18 13:30 -0700 |
| Message-ID | <b3c40cd2-a67a-4110-8050-9be4f9c223b4@googlegroups.com> |
| In reply to | #386152 |
On Saturday, June 18, 2016 at 1:34:08 PM UTC-6, Pentcho Valev wrote: > > "Doublethink means that Pentcho can delude himself into believing nonsense when the refutation of it is staring him in the face. Gary
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| From | JanPB <filmart@gmail.com> |
|---|---|
| Date | 2016-06-18 14:53 -0700 |
| Message-ID | <932ecf0f-d099-4d49-a338-1ad565441190@googlegroups.com> |
| In reply to | #386152 |
On Saturday, June 18, 2016 at 12:34:08 PM UTC-7, Pentcho Valev wrote: > Einstein's idiotic prediction that the speed of light falling towards the source of gravity DECREASES If you don't know something, don't post criticisms of it. > is a nightmare only for ordinary Einsteinians; the subtlest practitioners of doublethink in Einsteiniana teach it with ease: False. -- Jan
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| From | Pentcho Valev <pvalev@yahoo.com> |
|---|---|
| Date | 2016-06-19 15:03 -0700 |
| Message-ID | <a53827af-d3f4-4811-a7de-f66ed875e957@googlegroups.com> |
| In reply to | #385575 |
An interesting question in sci.physics.research: https://groups.google.com/d/msg/sci.physics.research/6culH45IIug/Zd9tBsCJAQAJ Nicolaas Vroom: "I'am interested in the behavior of a light signal with goes "undisturbed" straight towards to the (center of) the earth. For example starting half way between the Moon and the Earth. The initial speed can be "c". The first question is will this speed increase or decrease or decrease when the photons travel towards the earth." I replied but the moderators may not let the post through. Here is the reply: On Sunday, June 5, 2016 at 8:44:17 PM UTC+3, Nicolaas Vroom wrote: > > I'am interested in the behavior of a light > signal with goes "undisturbed" straight towards to the (center of) the > earth. For example starting half way between the Moon and the Earth. > > The initial speed can be "c". The first question is will this speed > increase or decrease or decrease when the photons travel towards the > earth. It will increase, like the speed of of ordinary falling objects (the acceleration will be g). General relativity absurdly predicts that the speed of the photons will DECREASE - the acceleration will be NEGATIVE, -2g. Pentcho Valev
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