|
|
Post by pumblechook on Sept 6, 2010 20:19:04 GMT 1
What is the speed of gravity?
|
|
|
|
Post by marchesarosa on Sept 6, 2010 20:24:31 GMT 1
Are there particles of gravity?
|
|
|
|
Post by abacus9900 on Sept 6, 2010 20:25:30 GMT 1
What is the speed of gravity? From current measurements it is the speed of light, pumblechook. |
|
|
|
Post by abacus9900 on Sept 6, 2010 20:27:09 GMT 1
Are there particles of gravity? The theoretical particle of light is the graviton, Mary. However, the graviton has yet to be scientifically observed. |
|
|
|
Post by Progenitor A on Sept 6, 2010 20:29:26 GMT 1
What is the speed of gravity? From current measurements it is the speed of light, pumblechook. How is the 'speed of gravity' measured? In order to measure it we would need gravity waves, and that is the great sought-after chimera of the Unified Theory Mind you, if gravity is a static space-time curvature then'speed' becomes a nonsense. |
|
|
|
Post by trollhunterx on Sept 6, 2010 20:29:35 GMT 1
What is the speed of gravity? gulls? |
|
|
|
Post by kiteman on Sept 6, 2010 20:37:34 GMT 1
As Nay says, we cannot measure the speed of gravity until we can detect gravity-waves.
Thus far, we have failed.
AFAIK, the expected speed of propagation of the curvature of spacetime is c. Safe to say, it cannot exceed c, as effect cannot precede cause above the quantum scale.
|
|
|
|
Post by pumblechook on Sept 6, 2010 20:42:32 GMT 1
Gaviota
|
|
|
|
Post by kiteman on Sept 6, 2010 20:43:28 GMT 1
Bless you.
|
|
|
|
Post by pumblechook on Sept 6, 2010 20:44:14 GMT 1
I would think it must be C or less otherwise it would mean we would have a means of transmission of information (by one object acting upon another) faster than C.
|
|
|
|
Post by abacus9900 on Sept 6, 2010 21:00:12 GMT 1
Well, the way they measure the speed of gravity is indirectly, by measuring the orbital decay of binary pulsars.
The orbits of binary pulsars decay due to a loss of gravitational radiation and the rate of such a loss of energy can be measured and because it is directly due to the speed of gravity you can work it out. It has been found by this method that the speed of gravity is to within 1% of the speed of light.
|
|
|
|
Post by abacus9900 on Sept 6, 2010 21:03:27 GMT 1
I would think it must be C or less otherwise it would mean we would have a means of transmission of information (by one object acting upon another) faster than C. Correct, because information would theoretically be able to be transmitted faster than c and we know that is prohibited. |
|
|
|
Post by trollhunterx on Sept 6, 2010 21:06:40 GMT 1
I would think it must be C or less otherwise it would mean we would have a means of transmission of information (by one object acting upon another) faster than C. Other than torturing a small king, that is. |
|
|
|
Post by speakertoanimals on Sept 7, 2010 15:44:07 GMT 1
There are measurements which have claimed to measure the speed of gravity WITHOUT measuring the speed of gravitational waves.
Some controversy over theoretical interpretation of their measurements.
'speed' of gravity has another effect. Some people think that the limit of general relativity is just newtonian gravity at the speed of light. Hence problems for earth going about the sun, since the attraction of the sun should be towards where the sun was 8 minutes ago, rather than where it is now. however, this is wrong, since correct limit is newtonian gravity at finite speed PLUS terms that depend on the momentum of the sun eight minutes ago -- hence in effect the terms can predict where the sun is now, hence force on the earth points in the right direction.
|
|
|
|
Post by abacus9900 on Sept 7, 2010 16:59:42 GMT 1
What did all that 'gobbledygook' mean? English please.
|
|
