Intelligent Design in Action: We Could Detect an Alien Civilization by Their Pollution, Astrobiologists Say

You might think fouling your own environment with lots of toxic smog is a poor indicator of intelligence. But obviously, heavy smog on Earth is gift of the industrial revolution. Our modern machines blow out smoke as a byproduct of energy production. That smoke is distinct from natural molecules. Methane, coal, and oil may be produced by natural causes, but burning them to do work takes intelligence.

Methane is produced naturally in a number of ways. For years, astrobiologists have thought th...