Radio waves (a type of light) is a cheap, easy way to communicate through space.

Changing the sun is seemingly out of the question, but you could put a satellite in far-orbit around the sun that concentrates/amplifies the sun's rays into a signal.

A powerful laser could be used for interstellar comminication (SETI is starting up an Optical-SETI program to search for such signals in addition to their regular radio wave search).

As far as I know, no planets have been discovered around the alpha-centauri system yet. The search goes on. Planets around other stars are hard to detect because they're so much dimmer and smaller than the stars they orbit.

• ah yes ... - perseus - August 13, 2001 - 21:41 UTC
  • We still don't know what powers the sun - weatherlawyer - August 14, 2001 - 03:22 UTC
    • We do know - mathman - August 14, 2001 - 04:13 UTC