Focus
"And since Earth's resources are finite, and it has a finite mass and receives solar radiation at a constant rate, human civilization cannot sustain an indefinite, exponential growth."
Please explain how this does not equate to the silly assumption that Earth must supply all the resources to expand into space rather than the new worlds colonized. It's a classic brain fart. Something that seems brilliant when viewed from one angle (a seemingly simple solution to a vexing question), but is utterly ridiculous when looked at from all angles and a big picture view.
Regards,
Mark