Kopeikin and "the speed of gravity"

The following post was just sent to sci.astro and sci.physics, which are USENET newsgroups.


"Steve Carlip" <carlip@dirac.ucdavis.edu> writes:

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[tvf]: Kopeikin has violated scientific protocol by changing the equations to be used for the analysis after the results are in, thereby presumably avoiding the embarrassment of having to announce an unexpected result.

[sc]: No. [This is] nonsense, based, as far as I can tell, on Van Flandern's lack of understanding of elementary general relativity. … To claim that this is ``changing the equations'' is just bizarre. … Even more bizarre is …<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

We discussed these matters amicably for ten years. During that time, we discussed many intricacies of GR, primarily around the transition from solutions to the field equations into equations of motion. On several occasions, you showed limited familiarity with various properties of the GR equations of motion (despite your expertise with the field equations), and had to get up to speed on them, as I did in some other areas. But during the last couple of years, since my views have been joined by others and found success in peer review and in the journals, you have turned nasty, often ignoring scientific points while just taking shots. That seems to have happened again here. It's the most common tactic used in society when losing an argument. Attack the messenger. If nothing else, it distracts from the losing on the merits.

I ordinarily do not even comment on trash like this. But a lot of people here still seem to respect your opinion, as I did myself until recently. But before I address the merits (or lack thereof) for your points, I'd like to comment on the rumor you have been spreading about my "lack of understanding of elementary GR", which is now commonly cited by those who look to you for leadership as a reason to ignore the strong scientific position I and others have successfully defended against every challenge, through peer review and into print in major physics journals. So PART I below addresses that matter, and PART II addresses your comments on the Kopeikin/speed-of-gravity matter.


PART I

One example where one of us "lacks an understanding of elementary GR" is over the physical meaning of "space-time". Many GR texts falsely imply that space-time is 4-space consisting of 3-space plus time as a fourth space-like dimension. That is nonsense. The fourth coordinate enters Pythagorean relations with a minus sign (e.g., x^2 + y^2 + z^2 - c^2 t^2), which changes its physical character. Specifically, it is easy to show that space-time is nothing more than proper time (coordinate time corrected for the slowing effects of speed and potential) multiplied by c to make it space-like. Trying to make it mysterious may make relativists feel special, but does not serve the interests of people who want to understand GR better.

Here's another example. Is ordinary 3-space curved in GR? At least at one time, you maintained that it was. That opinion, also commonly found in textbooks, stemmed from MTW's highly misleading mantra: "Space tells matter how to move. Matter tells space how to curve." But if taken literally, that leads to absurdities. Bodies with all speeds would all follow any true curvature of space. But that does not happen. Moreover, Earth is not following a curvature of space in its solar orbit. A taut rope joining any two points along Earth's orbit defines the shortest path through space, a path quite different than the orbit. Earth follows its actual orbit because gravitation induces a 3-space acceleration, not because of any curvature. We can't even compare GR to observations without using the 3-space equations of motion, which are expressions for the 3-space accelerations of bodies in *flat* coordinate space. Similar remarks apply to light-bending. The path of light curves through flat coordinate space, not vice versa.

The geometric interpretation of GR has also now been criticized in print. [“Experimental Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum Field Interactions”, T. Van Flandern and J.P. Vigier, Found.Phys. 32(#7), 1031-1068 (2002).] It works fine mathematically, but violates the causality principle (because a stationary body in a curved spacetime has no cause to commence motion unless a force acts) and requires the creation of momentum from nothing (because the field is static).

[Those interested in further details about these points are invited to join the on-going discussion at [url] metaresearch.org/msgboard/topic.asp?TOPIC_ID=149 [/url].]

There are other examples, but I need not belabor the point. No one has yet found a convincing rebuttal to these points. The upshot is that nothing changes about mathematical GR (we're not talking about any new theories here). But the correct physical interpretation of GR cannot be the geometric model now widely taught, but must be the original force model favored by Einstein, Dirac, and Feynman among others. Your own understanding of the physical interpretation of GR seems limited to what you were first taught, and has apparently not grown – even in the face of good and sufficient reasons why it should.

This is apparently what you mean by "… lacks an understanding of elementary GR". But the jury is still out about these challenges to the physical interpretation of GR. It may yet turn out that your phrase applies more to yourself than to me and the many physicists and science-interested persons who think as I do and can now understand GR because it makes physical sense. In any case, there is a difference between "lacking an understanding" and understanding something well enough to make a well-founded challenge to its interpretation.


PART II

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[sc]: The Einstein field equations cannot, in general, be solved exactly; one needs a systematic approximation procedure. There are two general forms of such a procedure (``post-Minkowskian'' and ``post-Newtonian''), which should agree in the regime in which they are both applicable. Kopeikin's first papers used a post-Minkowskian approximation; his recent paper used a post-Newtonian approximation. As expected, they give the same result. To claim that this is ``changing the equations'' is just bizarre.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Is this deliberately deceptive? Anyone can see that Kopeikin's equations have changed. So has his method of analysis, as explained in some of his press releases. My point (the "bizarre" one) didn't address which approximation Kopeikin chose to use. It addressed his new time transformation, tau = t (c/cg). It doesn't take a GR whiz to see that this time transformation changes coordinate time t into a time-like quantity tau that is small or approaches zero if cg is large or approaches infinity. Because we already know that the time coordinate is vital to the effects introduced by GR (light-bending, Shapiro delay, etc.), driving it to zero is certain to produce a hard failure to represent existing observations and experiments. In other words, if those equations were valid, cg = c would have already been established long ago, and this new experiment would have been a waste of taxpayer funds.

Frankly, I was expecting you, as a leader in your field, to be the one to do what Clifford Will has now done, which was to straighten out Kopeikin, who obviously got himself in way over his head. Kopeikin must have felt a sense of panic when the experiment didn't produce cg = c, and worked backwards from the "known" result to get the transformation h

Tom Van Flandern...

i have a hard time understanding you...

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>

Mark, I don't see that we are making any progress here. You seem in denial of what I was trying to teach you of standard dynamics (not MM things), which is your right. There's no "final exam" in this course.

v=32t feet/sec

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i pressume physics hasn't changed that much since i got lessons...

32 is a number, t is a variable and the units next to the formula stand for the units of v...then if t is in sec 32 must be m/sec^2... it is that simple...i use standard unit notation for well formed formulas (WFF)....do you subject to my way of defining the units for the variable v or you just want to cause a distraction from the real issue...that is your claim there can be infinite accelerations...

et v+dv=32(t+dt)=32t+32dt = v+32dt ---> dv=32dt ---> dv/dt =32 feet/s^2

you right on this but it's always better to assume an error than a tragic error...

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>

Your argument assumes acceleration is a smooth, differentiable function, which is an opposite assumption to the one I made. Impulses are only instantaneously infinite, then continuously zero.

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i already explained the notion of Dirac's impulse function which you seem not to comprehend...impuse is the derivative of acceleration also called "jerk"....<b>impulse is not acceleration</b>...i think you are confusing impulse with acceleration...i do not know if you are familiar with the type of bang-bang control systems used in space vehicles and sometimes on stealth bombers... the acceleration provided is a discontinuous function (bang and after dt another bang) but the impuse response when one uses the Dirac function leads to a piecewise continuous acceleration with a magnitude of a "bang"... then impuse is finite as it should be otherwise the vehicle would end up in deep space...

there can be no infinite accelerations...period... unless someone wants to "hide" something behind the concept of an infinite acceleration...

so let the issue of the subject matter go by and just stay friends...

I know how this can all really be tested. Generate a gravitational point source and measure its effects (time delay, magnitude, etc.) at a distance. Simple, huh?

(quoting tvf)

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
In our latest paper, “Experimental Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum Field Interactions”, T. Van Flandern and J.P. Vigier, Found.Phys. 32(#7), 1031-1068 (2002), we show that the geometric interpretation of GR violates the causality principle and the "no creation ex nihilo" principle, and is therefore not physically viable. That leaves only the force interpretation of GR, the one favored by Einstein, Dirac, Feynman and others.

"Force" here is used in the broad and familiar sense. Strictly speaking, we are talking about acceleration, not force, at the macroscopic level. Only in the microscopic details can we see something with the nature of force acting. Even then, it can be regarded as a series of momentum impulses.
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Now I'm confused, because in the paper "Repeal the Speed Limit..." you speak of geometric vs. field interpretations of GR. Now, in the paper "Experimental Repeal..." you speak of geometric vs. *force.* Where, how, and why was field transmuted into force? Or has it become force field and force is just shorthand? If my confusion is mistaken, I'd like to know how. Thanks.
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For now I'll give y'all a break from my endless harping on ideas for gravimetric or electrodynamic macroscopic (intra-solar system or interstellar) FTL communication experiments. Bet, though, that when the fish run again, I will be one of them. I will say only this for now: we all hear our bowels crying out that the answer to solving the FTL communication mystery is within our grasp, and this is understandable cause for much anxiety. To Change Paradigm, I see the need not only for breaking clean theoretically and experimentally, but epistemologically. In this vein, I recommend a regular visit to the virtual house of Tom's friend, Wal Thornhill ( holoscience.net ) for a fresh clearing out of the cobwebs of the mind.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Now I'm confused, because in the paper "Repeal the Speed Limit..." you speak of geometric vs. field interpretations of GR. Now, in the paper "Experimental Repeal..." you speak of geometric vs. *force.* Where, how, and why was field transmuted into force? Or has it become force field and force is just shorthand?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

This is my fault. I have tended to change the terminology depending on context because "field" can be so confusing. (It has two different meanings -- gravitational potential field and gravitational force field). And in the history of relativity, the notations were not used consistently because so many physicists made no such distinction, and treated the two as interchangeable. "Force" also carries some inappropriate baggage because fields produce accelerations (through momentum exchanges), not forces per se. [Aside: I never did like the concept that the force of the Earth on a marble is the same as the force of the marble back on the Earth. To me, that's "baggage".]

I'd like to start fresh, inventing new terms having no baggage. But that isn't going to happen, much less catch on. So I'm struggling to find terminology that is the least confusing. It is an evolving process. -|Tom|-

Today I received a newsletter from space.com again with some relevant info on the Kopeikin article. It seems there is more opposition to the article but no mention at all of the specific complaints from metaresearch. Some mathematicians found problems with his calculations.

The article can be found at [url] www.space.com/scienceastronomy/gravity_speed_030116.html [/url]

Rudolf