Scientists at the Weizmann Institute in Israel have found that ancient people not only knew how to use fire, but also developed sophisticated technologies using it to make tools. This was reported in a press release on the Institute’s website.
The researchers analyzed flint samples found in the vicinity of Kesem Cave, where ancient people who lived 200-420 thousand years ago created tools by splitting stones. Experts wanted to find out if the inhabitants of the cave could use fire to pre-harden the flint. To do this, they heated the samples to various temperatures and cooled them, after which they studied their chemical and molecular structure.
It turned out that people used different types of heat treatment to create different tools. For example, relatively low temperatures (200-300 degrees Celsius) were used to make stones with sharp edges. With intense heating up to 600 degrees Celsius, notches and chips were created.
Scientists do not yet know how the ancient people guessed to heat stones to different temperatures and how they controlled the heat treatment process. However, such skills allowed human ancestors to survive and develop successfully.