Kopeikin and "the speed of gravity"

I might be a little bit of a dummy here but from what starting point is Dr. Kopeikin claiming that c begins? I mean, does he claim that the speed of gravity is the same as the speed of light or is he claiming it travels at the speed of c from some other point of reference?
Example:
In Special Relativity, the only thing that is constant in all frames is the speed of light. Therefore, wouldn't the speed of light be the best starting point to make all measurements? Is Dr. Kopeikin claiming that the speed of gravity is c from a starting point of the speed of light? How would this work? Wouldn't that speed then be faster then the speed of light and violate the universal speed limit? This is very a difficult subject to uderstand.

Just learning!
Magoo

The Rod and Rock:

At t = 0 both have free-fall and the rock produces no added weight to the rod. They both accelerate the same and the rock will only cause problems if it doesn't fall off wherein its added momentum will kill you.

If the rock falling off the rod at t = 0, it won't kill you either since it has accumulated no momentum.


Mac

<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>

Just one. Which ordinary person on street, a child learning in primary school can understand and any person can verify the truthness of this experiment actually by conducting it without much money.

OK, Dr. Tom, I am going to reopen my one year old experiment with different arguments and gravitational tricks which I learned in past few months(yes, gravity is very tricky, very professional indeed).

If I fail to prove that my experiment will indeed work and measure speed of gravity to be instantaneous, then I will leave this board.

See you tomorrow.

-Abhi.

I'm sorry, but it is statements like this that really get me confused:
(Dr. VanFlandern)"But we are talking about the speed and acceleration at an instant, not how long they last. I can drive 60 miles per hour without driving either 60 miles or for an hour."

But if the car had a maximum speed of 60mph then the maximum accelration couldn't exceed 60mph then, right? I understand how you could accelerate upto 60mph but I can't see how you could accelerate past 60mph without violating the velocity limit assuming it was 60mph. So, if the velocity limit is (x) then how could you accelerate past (x), whether it was in hours, minutes, secs, nanosecs, instant and whether it was miles, feet, inches? How could it matter if the speed limit is x?



Just learning!
Magoo

<BLOCKQUOTE id=quote><font size=2 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>if the car had a maximum speed of 60mph then the maximum accelration couldn't exceed 60mph then, right?<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>

Because acceleration is not a speed nor anything like a speed, it cannot be compared to a speed. Change your question to this: "if the car had a maximum speed of 60mph then the maximum distance traveled couldn't exceed 60mph then, right?" You would correctly object: "But speed isn't distance, and the two are unrelated. You could go any distance at any speed if you drove long enough." The same remark applies to acceleration. If you accelerate for only one second, that <b>acceleration</b> can be very high without causing the <b>speed</b> to exceed 60 mph.

When I said acceleration was in different units than speed, I did not mean different speed units, such as the difference between mph and feet/sec. I meant different dimensions. Speed is in length/time units, whereas acceleration is in length/time^2 units. An acceleration cannot be compared to a speed unless you multiply it by a time interval so that the dimensions become the same -- length/time. You might do this, for example, by multiplying by the interval over which the acceleration is applied. That uses the formula v = a*t, where v = speed, a = acceleration and t = time interval.

For a constant "v", if the interval "t" is very small, the acceleration "a" can be very large -- without limit. -|Tom|-

Okay, thanks! I appreciate all of your help here. So let me see if I have this straight. The acceleration of light is different from the speed of light and the acceleration could be faster than the velocity?

But then I am back to square one in that acceleration is simply the rate of velocity over time. I'm not really sure how it is that acceleration is not a speed since it is derived from a speed.

Just our of curiosity, what are your calculations of:
1. The SPEED of gravity? (I think you say 20 billion c)
2. The ACCELERATION of gravity? (??)

Just learning!
Magoo