pull down to refresh

According to Einstein’s General Relativity, gravity travels at the speed of light. Unlike light, gravity can’t simply be switched on and off, and is also extremely weak. Over the years, various attempts have been made to measure the speed using studies of astronomical phenomena, such as the time delay of light as it passes through the huge gravitational field of Jupiter. While the results have been broadly in line with Einstein’s prediction, they’ve lacked the precision needed for compelling evidence. That’s now been provided by the celebrated detection of gravitational waves. Analysis of the signals picked up by the two giant LIGO instruments in the US has confirmed that gravity does indeed travel through space at the speed of light.
Gravitational waves, as visualised in this artwork, helped us prove that gravity travels at the speed of light
This is from BBC Science Focus magazine.
Wonder what's the current status of research in the quantum field theory interpretation of gravity. Quite unlikely to ever observe gravitons (these would require Planck scale energies, at least 10 orders of magnitude larger than what is currently achievable at the LHC), so I wonder if the gravitational waves, a macroscopic observable of gravity, indirectly shed some light on those hypothetical gravitons.
reply
General relativity explains gravitational propagation as spacetime distortions moving at light speed, while quantum gravity predicts gravitons might do the same, but this remains theoretical.
reply
Now, it remains to be determined whether it is just the gravitational field propagating at the speed of light or if it is graviton particles moving at the speed of light.
reply
A complete theory of quantum gravity is needed to determine if gravitons exist and how they relate to gravitational waves.
reply