most people say 20,000 million years ago, but thats impossible!
take it out of the oven and leave on a raised surface. leave for as long as it takes to cool down. Ten to 15 minutes should be plenty.
a valley
pipe
The East Africa Rift System
Since the begining of time.
Long-wave radiation and visible light.
8 minutes or 500 seconds(approx.)
It depends how long you're heating it.
By residual heat - they have no fuel. See related question.
If you only ran 15 minutes it shouldn't be very long of a cool down. Just don't sit down after, your legs will get really sore
A pipe is a long tube in the ground that connects the magma chamber to the earths surface.
It takes about half an hour.