“Have I ever told you about the Gaia theory?” asked Dion as he passed the hash pipe.
“No,” said Wes. He took an enormous hit and passed the pipe back to Dion.
“In the 1960s James Lovelock was a freelance consultant for NASA. They asked him to help them come up with methods for determining if life existed on other planets.” Dion paused to finish what was left in the bowl. “This is some mighty good hash”, he thought, “better finish the story before I’m incapable of telling it.” He continued speaking, “So anyway, Lovelock thought about this and came up with a more general view of life. He came up with a test based on the fact that all living organisms extract nutrients from their environment, chemically alter them, and leave behind waste products. Naturally a good sign of this activity was a complex atmosphere filled with reactive gasses like oxygen and methane.”
Wes interrupted, “Did you know that cow farts are contributing to the ozone hole?”
“Please don’t interrupt me Wes,” Dion replied with an authoritative tone.
“Sorry,” said Wes, slightly ashamed.