The Clacton Spear is the tip of a 450,000-year-old fire-hardened spear discovered in England.
It has long been believed that the practice of heating a pointed spear tip in the fire was a way of making it sharper and harder.
So they harvested 20 rods from local hazel trees and spent weeks abusing them inside machines of very precise, codified destruction.
First, each rod was divided in half.
Then they tested each rod for hardness, as well as how each responded to bending and sharp impacts.
What they discovered was that the fired wood was indeed slightly harder, but it was also significantly weaker.