Gravitational wave doesn't carry mass. It travels at the speed of light, so it has to be massless. In fact, in 4D gravitational waves can arise even without any mass/energy source.
I suppose I should have said energy, not mass, but unlike a photon which can disappear into nothing, leaving just the energy, a gravitational wave can't ever vanish entirely, so it's more like mass in that regard.
And don't forget that a wave can travel at the speed of light even if the wave is carried by massy particles that can not.
> I suppose I should have said energy, not mass, but unlike a photon which can disappear into nothing, leaving just the energy, a gravitational wave can't ever vanish entirely, so it's more like mass in that regard.
This sentence is wrong. I'm not sure what you mind with "photon which can disappear into nothing, leaving just the energy", but gravitons [1] can do the same thing.
A gravitational wave is made of a huge amount of gravitons, it's like the electromagnetic wave produced by radio transmitter. I´m not sure if with your classification the electromagnetic wave produced by radio transmitter "can't ever vanish entirely".
[1] If they exist. I'm almost almost sure gravitons exist. There is still not a good quantum gravity theory, but I strongly believe that we will discover it in the future an it will include gravitons.
> can disappear into nothing, leaving just the energy", but gravitons [1] can do the same thing.
I'm not convinced they can vanish, unlikely photons there is nothing that can stop a graviton, they are able to travel through all matter.
So given they have unlimited range, how would one vanish?
> A gravitational wave is made of a huge amount of gravitons
That is not established at all!! Not to mention it's mathematically identical to saying gravity is made up of gravitons, and we certainly have not established gravitons exist even for plain gravity.
After all a gravity wave is just a modulation in gravitational force, not some new entity.
Gravitons (if they exist) will interact with any particle with mass, so a big heavy wall should stop them. Since the interaction is extremely small, the wall must be extremely heavy, probably bigger than a galaxy, not just a normal wall.
>> A gravitational wave is made of a huge amount of gravitons
> That is not established at all!!
Completely agree. My conviction that they exist is based in many assumptions. In particular that we will someday have a quantum gravity theory that will be correct and that it will integrate nicely with the other physics theories. It's a good guess, but it's possible that we will not know the answer for hundreds of years.
