Just 100 years ago, Einstein announced his General Theory of Relativity. Four decades later, I used it to calculate the rate of a clock orbiting the Earth. It has turned out to be of importance for the GPS system, which depends on accurate clocks in navigation satellites.
Einstein and the General Theory of Relativity (GR)
In a Wall Street Journal op-ed (“Without Albert Einstein, We’d All Be Lost”), Robbert Dijkgraaf (director of Princeton’s Institute for Advanced Study) reminds us that on Nov. 4, 1915, Albert Einstein, working alone in wartime [World War-I, 1914-18] Berlin, submitted the first of four scientific papers that would change the course of physics and our view of the Cosmos: “His general theory of relativity (GR) is perhaps the greatest achievement of a single human mind.” Although it made Einstein the most famous scientist in history, he did not live to see the full impact of his ideas. He did not foresee earth satellites, lunar landings, or the application of GR to GPS, the Global Positioning System of navigation satellites.
As Dijkgraaf writes:
“Only now, a century later, are we gathering apples from the tree he planted: black holes that tear stars apart … ; cosmic gravitational lenses that distort images of faraway galaxies, as if seen through a funhouse mirror. And perhaps the biggest wonder of all: a comprehensive and detailed understanding of the evolution of the universe. Amazingly, in just 100 years, humankind has uncovered 13.8 billion years of cosmic history.