• provided powerful evidence that atoms and molecules actually exist, through his analysis of Brownian motion.
• explained the photoelectric effect, proposing that light came in bundles. Bundles of light (he called them quanta) with the correct amount of energy can eject electrons from metals.
• proved that everyone, whatever speed we move at, measures the speed of light to be 300 million meters per second in a vacuum. This led to the strange new reality that time passes more slowly for people traveling at very high speeds compared with people moving more slowly.
• discovered the hugely important and iconic equation, E = mc2, which showed that energy and matter can be converted into one another.
• rewrote the law of gravitation, which had been unchallenged since Izzac Newton published it in 1687. In his General Theory of Relativity, Einstein:
» showed that matter causes space to curve, which produces gravity.
» showed that the path of light follows the gravitational curve of space.
» showed that time passes more slowly when gravity becomes very strong.
• became the 20th century’s most famous scientist when the strange predictions he made in his General Theory of Relativity were verified by scientific observations.
• spent his later years trying to find equations to unite quantum physics with general relativity. This was an incredibly hard task for him to set himself. To date, it has still not been achieved.