For most of the medieval period, military power was limited to human strength. Then came the first use of chemistry on the battlefield—gunpowder. It didn’t take long for gunpowder to become the principle means of making war and the explosive fuel of social unrest. But beyond that, the creation of gunpowder spurred on the first major advances into the scientific method. What began as a noisemaker to scare the enemy, changed everything. Perhaps more than any other invention.