Semi-OT: A General Tech Question Thread for me :)

[Hunpecked]

Given a billion years of FTL "they" could colonize, explore, or stake out every planet in the known universe. If for some reason "they" only live nearby, perhaps they'd come over just to see what's causing all the radio pollution.

Being serious for a moment, it seems the Earth itself sends radio signals ten times stronger than Jupiter's and much stronger than humanity's:

http://www.gi.alaska.edu/ScienceForum/ASF6/612.html

Assuming that a strong magnetic field is essential for life (deflecting all that ionized radiation), that alone might attract some attention.

Using current technology, a radio telescope at the distance of the star Vega would need to be about half the size of the mean Earth-Moon distance to pick up TV signals from Earth:

http://www.computing.edu.au/~bvk/ast.../HET608/essay/

Presumably it wouldn't require a single dish that size; a Very Long Baseline Interferometry setup of the proper size might do the trick. Military/scientific signals are more powerful, but probably too directional and/or intermittent to draw attention.

Of course given a billion years of research and a working FTL principle, all bets are off.