interesting story for this crowd
http://www.msnbc.msn.com/id/32410104/ns/technology_and_science-science/
"Early humans crossed a threshold around 75,000 years ago....
By heating up stones in a fire before chipping away at them to make blades, early humans could make tools sharper and produce them more efficiently. "
http://www.msnbc.msn.com/id/32410104/ns/technology_and_science-science/
"Early humans crossed a threshold around 75,000 years ago....
By heating up stones in a fire before chipping away at them to make blades, early humans could make tools sharper and produce them more efficiently. "