German-born physicist Albert Einstein (1879-1955) was so influential, his very name has become synonymous with genius. While working as a patent clerk in 1905 at the age of 26, Einstein submitted four papers to the German journal Annalen der Physik that changed humanity’s perception of time, gravity, and light. Today, historians mark the year as Einstein’s annus mirabilis, or “miracle year” — and he was just getting started.
Much of Einstein’s work is famously dense. Few people other than physicists need to fully comprehend the mind-bending ideas behind the general theory of relativity and Einstein’s other theories, but these discoveries form the bedrock of technologies the rest of us enjoy every day. Here are five ways Einstein’s ideas changed the world, and continue to provide a roadmap for humanity’s future.
GPS Would Be Impossible Without the General Theory of Relativity
Some 10,900 nautical miles above our heads, 31 satellites orbit Earth as part of the Global Positioning System (GPS) — but if it wasn’t for Einstein, those satellites would be little more than space junk. The very foundation of GPS is accurate timekeeping, as satellites need to keep time to correctly log the distance from a ground-based receiver (such as your smartphone). GPS satellites are so precise, the atomic clocks on board are accurate to within three-billionths of a second, a feat impossible without Einstein’s special and general theories of relativity. The special theory of relativity states that time flows differently depending on velocity. Because satellites travel at 8,700 miles per hour, they “lose” 7 microseconds per day compared to Earth-based receivers. Additionally, Einstein’s general theory of relativity — an idea published in 1915 that basically elaborates on his previous theory by throwing gravity in the mix — similarly states that distance from a source of mass, in this case the Earth, also affects the flow of time. This means that technically speaking, your head ages slightly faster than your feet because your feet are closer to the Earth (on time scales that are ultimately negligible). Today, GPS takes into account this “time dilation,” so satellites always know where you are when you open Google Maps.