Hi,

Thanks for your interesting comments.

Colonizing the galaxy is actually not that impractical. Colonizing several or all galaxies is harder though. See this recent paper for the math:

Armstrong, Stuart, and Anders Sandberg. 2013. “Eternity in Six Hours: Intergalactic Spreading of Intelligent Life and Sharpening the Fermi Paradox.” Acta Astronautica 89 (August): 1–13. doi:10.1016/j.actaastro.2013.04.002. http://commonsenseatheism.com/wp-content/uploads/2013/05/Arm...

It's an interesting question to pose, what telltale clues could you infer from a binary star system that would suggest there is life on it.

Indeed, that is the main challenge here.

I suppose when analyzing the metabolism of these binary star systems you would want to look for something that looked more like an engine and less like a firework to truly determine if there is life out there.

Interesting suggestion. For more info, you can have a look at this news item about black holes in binary systems: "How black holes change gear", http://www.sciencedaily.com/releases/2012/06/120607142254.ht... What do you think? Astrophysical or astrobiological phenomenon?

I also wrote a short working paper summarizing a metabolic argument for the existence of starivores:

Vidal, C. 2013. “Starivore Extraterrestrials? Interacting Binary Stars as Macroscopic Metabolic Systems.” Working Paper. http://student.vub.ac.be/~clvidal/writings/Vidal-Starivore-B....

Best, Clément Vidal.