Quote:
Originally Posted by Anthony
Earth 250 years ago, as you specified, though even 5,000 years ago you'd be able to detect and at least recognize as odd agricultural patterns in areas such as the Nile.
|
Okay, fair, for interplanetary distances. And I'll stipulate the Nile as looking odd a long way back, though I'm not sure if extraterrestrials would look at it and say "agriculture!" rather than just "anomalous growth pattern!"
Bill Stoddard