Gravity and Orbital Mechanics - Physics 101 / AP Physics 1 Review with Dianna Cowern

Another great lesson. Thank you.

You mention gravitational waves travel at the same speed as light (in a vacuum, in a previous lesson I think you said it varies, and potentially the key to my question below). I, for no valid reason, believe light is not travelling at the max speed possible. Said speed is just a limitation of light but there could be something that travels faster. We can't see it of course because our eyes work on the basis of light.

I have asked a few if gravitational waves travel faster than light but am yet to get a satisfactory answer. I base this question on my extremely feeble brain recognising that light arrived 1.7 seconds later than a gravitational wave from the same location (if I understand correctly the observable gravity actually stopping). Kind of makes sense, then, that the gravitational wave was travelling faster.  I am of course referring to the neutron star merger in NGC4993 and GW170817. The best information I can get is from Ask Ethan. Where the explanation is stuff got in the way, slowing light I think (by not being in a vacuum), at the point of explosion. So essentially light left (crudely speaking) 1.7 seconds later than the gravity wave stopped.

Are you able to explain this in the moderately easy way you explain all your lessons? Probably an entire lesson after your 101 syllabus has finished. Or maybe I'm right and the speed of light in a vacuum is not the limitation of speed we have been taught. ;)