Using High Energy Particles to Learn About Smaller Things

In 1908, two physicists at the University of Manchester used alpha particles to bomb atoms with energetic particles. They expected that electrons would not be able to deflect thesealpha particles from a thin sheet made of gold. But they were surprised by how strongly someAlpha particles deflected off their target and even recoiled back where they came from. The experiment revealed an atom's nucleus is much heavier than previously thought.