@themodestokid - Yes, we know gravitational waves move at the same speed as light! First, Einstein's theory of gravity predicts this. But now, thanks to gravitational wave detectors on Earth, we've actually seen neutron stars collide and emit gravitational waves that reach us at the same time as the light produced by the collision!
"But the greatest confirmation that the speed of gravity equals the speed of light comes from the 2017 observation of a kilonova: the inspiral and merger of two neutron stars. A spectacular example of multi-messenger astronomy, a gravitational wave signal arrived first, recorded in both the LIGO and Virgo detectors. Then, 1.7 seconds later, the first electromagnetic (light) signal arrived: the high-energy gamma rays from the explosive cataclysm.
Because this event took place some 130 million light-years away, and the gravitational and light signals arrived with less than a two second difference between them, we can constrain the possible departure of the speed of gravity from the speed of light. We now know, based on this, that they differ by less than 1 part in 10¹⁵, or less than one quadrillionth of the actual speed of light."
@themodestokid - Yes, we know gravitational waves move at the same speed as light! First, Einstein's theory of gravity predicts this. But now, thanks to gravitational wave detectors on Earth, we've actually seen neutron stars collide and emit gravitational waves that reach us at the same time as the light produced by the collision!
Gregory's Server
@johncarlosbaez I mean I assume they do but have very little actual knowledge of the subject