What are the advantages of using gravitational waves for communication? They seem incredibly difficult to produce or detect, and don't travel any faster in a vacuum than electromagnetic waves.

He is suggesting that advanced civilizations would use gravitational waves to communicate because they are hard to detect.

This summary of Dark Forest helps explain why a civilization would want to conceal their communications[0].

[0] https://www.quora.com/What-is-the-Dark-Forest-Theory-of-the-...

Do they potentially propagate through matter with less interference than electromagnetic waves? I have no idea, that would be the only thought.. otherwise yeah I don't see what the appeal would be.. and how the hell do you create them on any small scale that can be actually read by someone, since gravity is such a weak force?

Because gravitational waves get "dimmer" inversely with distance, while electromagnetic waves get dimmer inversely with the square of the distance.

No, both gravitational waves and electromagnetic waves decrease in intensity with the square of distance.

(This is true of any wave in 3D space, because the area covered by a wavefront increases with the square of distance. The inverse square law is a consequence of conservation of energy.)

The energy of the gravitational waves will decrease with the square of the distance, but the amplitude will not. We can detect this in LIGO. This amplitude is also known as "strain". For more discussion check this page: http://spiff.rit.edu/classes/ast613/lectures/grav_i/grav_i.h...

The equation for strain is: http://spiff.rit.edu/classes/ast613/lectures/grav_i/eqn_stra...

The same is true of electromagnetic waves. The amplitude of EM waves decreases inversely with distance, and the energy decreases with the inverse square.

Your original comparison of EM waves to gravitational waves is only possible because you looked at the power of one, and the amplitude of the other. If you compare apples to apples, they're the same.

A question for typon: in light of this information, do you still believe that advanced enough civilizations would use gravitational waves for communication?

Why are gravitational waves better for long distance communication than EM waves?

It's hard to shield them.

But bandwidth would probably suck.

Oh come on, just collapsing some million black hole pairs to get the latest JavaScript based ad across the whole Galaxy. Let's not pretend there are still people with a 56k gravitation modem out there.

We will send you thin information even if you don't want it! Otherwise, there isn't much obstacles in empty space.

they can propagate through literally anything

So do neutrinos. They're a lot easier to make.

TBF, the waves propagate more literally through anything than neutrinos. In a, you know, "technically correct" sense.

spoilers... Ugh.