Gravity! It cures what ails ya!
Posted on 09/05/2002 9:08:22 AM PDT by RightWhale
Scientists attempt to measure speed of gravity
UNIVERSITY OF MISSOURI NEWS RELEASE
Posted: September 4, 2002
Ever since Albert Einstein proposed the general theory of relativity in 1916, physicists worldwide have tested the theory's underlying principles. Whil some principles - such as the speed of light is a constant - have been proven, others have enot. 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.
Measurements will be made using the NRAO's Very Long Baseline Array (VLBA), a series of 10, 25-meter radio telescopes located from the Virgin Islands to Hawaii, and the 100-meter radio telescope in Effelsberg, Germany, which is operated by the Max Planck Institute for Radio Astronomy. "Results from recent VLBA test observations indicate we can reach the accuracy necessary to determine the speed of gravity if the experiment goes well," Fomalont said.
"Japanese and NASA scientists also will conduct the experiment independently using other telescopes around the world, so we'll be able to compare our findings," Kopeikin said. "We believe the general theory of relativity is correct and that the speed of gravity is equal to the speed of light."
"The techniques we've employed for this experiment can also be used to more precisely determine the position of other objects in space," Fomalont said. "With more exact positioning of satellites, we could improve telecommunications. Unmanned space navigation could also be improved, allowing us to explore the solar system more deliberately."
The scientists said final results from the experiment should be available in mid-November.
When the piece of angle iron fell off the welding table onto my foot the one time I wasn't wearing steel-toe boots, "something" was going on.
A very badly written pair of sentences... speaks of the quasar when it means the EM emissions from the quasar -- a big difference.
Gravity! It cures what ails ya!
Yes. Thinking about that, gravity lenses are usually much bigger objects. This experiment is looking for subtle effects.
We could figure this out for sure if we found a double star with both suns orbiting close together and a planet orbiting both at a greater distance. There would be regular motion in the system, but some kind of phase lag in the planet's orbit that could be measured.
You're quite right, of course, and I even realized that when I wrote what I wrote, but my position was (and is) that clarity is a higher value than absolute elimination of redundancy.
...as I further illustrated by using the phrase "absolute elimination..." 8-)
You are not under continual bombardment. You are expelling energy continuously. You are continually bombarding your environment.
And, as long as the rate of bombardment is equally distributed around your entire surface area, and as long as the speed of the energy particles is very high compared to your own speed, then I don't see how inertia would be impacted.
However, it might explain some of the predicted behaviors at speeds near c as your "gravitons" start to build up in the direction you are travelling.
Shalom.
No, it's just that gravitons are much more massive than photons.
Shalom.
It would be easier to measure its impact on the sun, the sun being farther away and all.
Shalom.
In a closed system, true. The gravitons have to be coming from somewhere. Maybe that's why living things grow old? Bigger problem explaining the issue for rocks, though.
Shalom.
She sucks the life out of anything.
Shalom.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.