speed of gravity

For those who may be interested, physicists have now measured the speed of gravity.

This is from an article released by University Of Missouri-Columbia;

Ever since Albert Einstein proposed the general theory of relativity in 1916, physicists worldwide have tested the theory’s underlying principles. While some principles - such as the speed of light is a constant - have been proven, others have not. Now, through a combination of modern technology, the alignment of a unique group of celestial bodies on Sept. 8, and an experiment conceived by a University of Missouri-Columbia physicist, one more of those principles might soon be proven.

“According to Einstein’s theory, the speed of gravity is assumed to be equal to the speed of light,” said Sergei Kopeikin, MU associate professor of physics and astronomy. “While there is indirect evidence this is true, the speed has never been measured directly, and that’s what we’re attempting to do in an experiment that will not be possible again for another decade.”
The experiment will involve precisely measuring the angular distances between several quasars, celestial objects in distant galaxies that resemble stars. On Sept. 8, Jupiter will pass very close to the primary quasar. When it does, its gravity will cause the quasar’s position in the sky to shift by a distance that depends on the speed of gravity. Kopeikin and Ed Fomalont, a radio astronomer with the National Science Foundation’s National Radio Astronomy Observatory (NRAO), will use an observational technique they developed to compare the position of the primary quasar to the position of other quasars unaffected by Jupiter. Using their data, they hope to confirm the accuracy of Einstein’s theory further.

Their findings have revealed that gravity travels at 0.95 the speed of light. At least that’s what I’ve heard from a tv program… but it might be 100% the speed of light, I’m not sure.
Anyhow, to me this is somewhat of a disappointment. Although I find Einstein’s theory of general relativity very intriguing (from what I can make of it) and I don’t necessarily desire to have it disproved, I’m bothered by the universal speed limit which the speed of light represents. Earlier I had the idea that gravity might have been different from other forces partly due to its supposed “instantaneous” nature. I thought that maybe gravity was woven into the very essence of space-time and so it would have had far reaching ( literally to the ends of the universe) effects. It gave me a sense of joy to know that every planet, every star, hell… every particle of matter has some sort of direct relation to me ( a gravitational effect) and vice versa.
Now with the speed of light being the constant that it is, this can no longer be a viable way for me to look at my place in the universe. This is because it would take light years for ANY gravitational force (however extremely weak) to make its way here and directly affect me in ‘realtime’ and for me to have some insignificant affect on the cosmos.

I guess we will always be bound by one limit or another… :unamused:

The article version on the web which I read, which I no longer have the link to said, it was 0.95 with a margin for error of 0.025, so they said that it could be 0.975 or 0.925 the speed of light.

The limit makes sense, as there has to be state changes of small sub-atomic stuff. So all things will be limited by how fast these little guys can change. I’ve been working on an idea called Solid Space, based off the idea that for anything to move there must be state change of either the object or empty space. So this changing of state speeds will be a limiting factor. Also this effect how we look at time, again part of the theory I’m working on, time is just movement, nothing more. I hope to post my theory to the Essays section of the board some time next month.

PV

pv wrote:

thanks for the info… i wasn’t sure.

Interesting. The articles I read on the subject indicated that gravity may have a speed faster than light (1.06 times), although the 20% margin for error makes this a little unbelievable.