Reply #36: I would expect somewhat ambivalent evidence of intelligent BEMs within a century..

[Fumesucker]

Probably not attempts to communicate but more likely just seeing really large engineering projects a long way away, Dyson Spheres, Bussard Ramjets, black holes as artificial power sources or something completely unexpected but impossible to explain by natural means.

Neutrino and gravity wave telescopes are only now becoming seriously operational, every time we find a new way of looking at the universe we find stuff we didn't expect.