Eclipse,
I really enjoy discussions about the origin of anthropogenic fire. Thanks.
Striking flint does not produce sparks except with certain kinds of metal bearing lode. That could have been discovered by accident. However, the leap from that to rubbing sticks together is a very long leap. It requires comprehension that the act of striking stones together creates friction.
This means, according to your "accidental discovery" hypothesis, that some superb genius in humanity's distant past got intuitively beyond the pretty sparks and understood the underlying physical principle: (A) friction creates heat, (B) enough heat produces fire, therefore (C) enough friction produces fire.
Then someone got the bright idea that this nifty parlor trick had some practical application (i.e. it had some technological benefit for the species) like scaring/herding game or cooking food, and that the skill should be handed down to the next generation.
Next, this knowledge would have to have been retained through quite a few potential special extermination periods.
Fire is heat that burns things. It often begins accidentally from lightning strikes in dry brush. We call it "a conversion of potential energy into the form of heat". Our distant ancestors didn't understand it in those terms but "knew" what it was, anyway. Knowing what fire is does not seem to be odd knowledge among the animal kingdom. Lots of animals have instinctive responses to fire. No animals save humans use and manipulate the properties of fire for anything.
If I remember my history correctly, the "creating sparks" method of anthropogenic fire was a late arrival compared to the "rubbing sticks" method. I believe the "fire from concentrating sunlight through a convex refractive medium" was much later still.
Were you genuinely referencing Ice Age as a source of some kind? (just kidding)
eclipse: They had to have known that rubbing sticks together would create heat / fire.
Exactly my argument. How did they know this? Trial and error? Something like a group of extremely bored prehistoric men and/or women playing a game called "Ook eh-eh ookie ahg-aghh Uh-ghug"? (rough translation: "Rubbingsticks make hot dancy Light")
Respectfully,
AuldSoul
