Kopeikin and "the speed of gravity"

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[Abhi]:
(1) Aaccording to Dr. Kopeikin, c = speed of gravity.
(2) According to USENET SRians crackpots, c = de-compression wave,
(3) According to Tom Van Flandern, c = billion time faster than light.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

I'm in camp #2. Gravity is not a factor in transmitting the force of the rock, and even if it were, the acceleration of the rod would build up very slowly. Please do not separate me from my fellow crackpots. <img src=icon_smile_dissapprove.gif border=0 align=middle> -|Tom|-

The speed of gravity (c_g) is between c and infinity.
Let take the equation and fix c_g=c to predict what should be the mesurements of the jupiter transit.
Do the same thing with c_g=infinity.
If equations doesn't allow infinity set c_g= big big number.
Whe will have a braket of possible mesurements. If equations doesn't allow infinity set c_g= big big number.
But equations to use? GR SR MM ...?
The equations that describe the jupiter transit must be proofed mathematically valid in the frame of the theory evaluated.
May be we will find in some theory that, the experiment would not be influenced by the speeg of gravity?
Is the precission of mesurement inside the range of possible mesurements?
Let see if whe can design an experiment to mesure c_g.
What instrument do we need to do this mesurement?
Gravimeter sensitivity? Gramvimeter sampling rate?
Around 1 second sampling rate that's the problem for laboratory experiment.
TVF often spoke of mesurements made during solar eclipse(s) where can I find a description of this/those experiment(s)?
Asteroid regularly pass by the earth. Can it be used to make some mesurement?
Would a graviter operating outside gravity field be more performant?
Is their others way to mesure c_g ?

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>[jacques]: Let take the equation and fix c_g=c to predict what should be the mesurements of the jupiter transit. ... Do the same thing with c_g=infinity.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

The prediction for the Jupiter-quasar appulse (not transit) depends on assumptions. For the assumptions normally made in GR, SR, and MM, the potential fields of each source mass are shaped instantly by gravitational force. When potential fields for more than one body are combined, these interact instantaneously, again by assumption. I.e., no propagation delay between fields is considered. So predictions are not "absolute", but depend on assumptions. But any assumption other than instantaneous interaction leads immediately to an experimental contradiction.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>Let see if whe can design an experiment to mesure c_g.<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

We have six strong experiments now. How many are needed to have confidence in the results? See "The speed of gravity -- What the experiments say", Phys,Lett.A, v. 250, pp. 1-11 (1998), also available at [url] metaresearch.org/cosmology/gravity/gravity.asp [/url]. This paper also describes each experiment (or gives a citation to a full description), including the solar eclipse experiment. -|Tom|-

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

How can one stone kill two persons at two different points in space during same time interval t?

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that's where your problem is pal... no stone kills both...one is killed by the stone and the other by the rod... now, if it just happens that the momentum of the rod includes the momentum of the stone due to propagation delay, that's another story pal...

the cause is the stone removal but you have two different effects, the stone moving and the rod moving (with or without the info of the stone removed) so you have two effects connected in some mechanical way to the same cause. i think that once you look at the two effects as a single one then you have a problem...

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

As this information regarding separation of stone from upper end has not reached to lower end during time interval t = L/c, the lower end will behave as if nothing is happened and the lower end will still have "weight" of this stone even if the stone is separated.

So during this time interval t, the rod moves down and crushes your head. You are dead.

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your experiment is no good. the question about the "speed of gravity" remains valid....try another one but please, I really mean that, don't you play with my forehead...only yours... cheers!

[/quote]

I'm in camp #2. -|Tom|-

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Binngo!!

This is how you think.......

Molecules of water in vertical pipe can be considered as small elastic balls. When we place load on upper surface of this water column, first molecule i.e. "ball" is compressed, then second, third...... This is how force is propagated through compression wave in elastic medium.

Then how about this.........

There is vertical pipe full of water. In this pipe, there is weigh machine at the bottom of this water column. At t = 0, on the upper side of this water column, other heavy metal disc is placed. How much time it will take for lower weigh machine to measure weight of this upper metal disc? And how this information, that we have placed metal disc on upper surface of water column will be communicated to lower end and eventually lower weigh machine?

We may say that when we place metal disc on upper surface of water column, molecules of water on upper side will be compressed (and indeed it happens) and this compression wave will propagate with acoustic velocity across water column towards lower end. When this compression wave reaches to lower weigh machine, it will measure weight of metal disc. Doesn't it mean that gravitational force F = mg propagates across water column through compression wave with acoustic velocity?

Certainly you will say, No. Then how does the information regarding weight of metal disc will be communicated to lower weigh machine? Is there any mechanism, which can describe way and speed of this communication?

We can detect this compression wave and its speed. But we do not detect any other "wave" which propagates across water column of which speed is greater than this compression wave and in which information regarding mass and gravity of planet is encoded. We haven't detected any such thing. Perhaps we will be compelled to think that this gravitational force F = mg propagate across water column with speed of sound through compression wave!

But let us find out where we are doing mistake

If information regarding weight of metal disc on upper surface of water column is carried by compression wave, then on same line we should say that when we remove this upper metal disc from surface of water, de-compression wave will propagate towards lower weigh machine carrying this information and only after that lower weigh machine will show decrease in weight. .

In earlier situation metal disc is on surface of water compressing water. Let us assume that this water is compressed upto point d on vertical pipe by distance h. Below point d, water can not be compressed. Now at point d, we have inserted metal plate so that weigh machine is separated from rest of water column but due to this metal plate the water column remains in compressed state. Now if we lift this upper metal disc, will decompression wave propagate across water column carrying this information?

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Remember we have inserted metal plate at point d so that water column remains in compressed state. If we push this metal disc in downward direction, this metal can slide in downward direction further compressing water. But this metal plate can NOT move in upward direction above point d.
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We should come to conclusion that, as water is not de-compressing as we lift metal disc, there will not be any de-compression wave. As there is no de-compression wave propagating across water column, the lower weigh machine should show reading as if nothing is happened at upper side of water column. That means lower weigh machine will measure weight of upper metal disc even if it is not there!

-Abhi.

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote> We have six strong experiments now. How many are needed to have confidence in the results?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
Yes that's a good question. I already read those article and to me it make a lot of sense, specialy the gravity aberation test. The lower limit for gravity is so high that we can envision the possibility of c_g=infinit. Then why some people are trying to prove that c_g=c ?
Is there some flaw in these experiments ? I am conviced that anyone who thakes the time to do your experiments will get the same results. For example we are still in orbit with the sun since millions years. What do those people need more? May be a gravity speed meter, with led display. <img src=icon_smile_cool.gif border=0 align=middle>