Can you share what the final desired goal is? It sounds like your goal is actually to provide your services to Bob securely over the internet, is that a fair description? You mentioned eventually grabbing a domain, how do you feel about publicly exposed services with authentication? For instance, I use authentik in front of Jellyfin and paperless myself for a little extra authentication juice.
In case you needed to look it up like I did:
Impact of gravity on fluid dynamics, gravity waves: https://en.wikipedia.org/wiki/Gravity_wave
Impact of gravitational fields in astrophysics, gravitational waves: https://en.wikipedia.org/wiki/Gravitational_wave