EclecticLip

For those of you who’ve never seen bacteria grow in a petri dish, here’s a cool little animation showing the spread of Wal-Mart across the US. It isn’t quite exponential growth — though it seems that way for awhile — I think it’s more of an S-curve (sigmoid curve — like a pH chart.)

The chart is probably a good proxy for US population centres — and thus, population density.  I believe Wal-Mart targets town 30,000 and bigger.  Anyways, you can see how (relatively) empty the western half of the US is, compared to the eastern half.  It’s as if there was a dividing line.  (Note: I’m excepting the highly populated strip along the West Coast).