One Hundred Years of Relativity
Albert Einstein's theory of relativity has provided fundamental insights into the history and nature of the universe, from the Big Bang to wormholes and evaporating black holes. But there is a flip side to Einstein's famous explanation of how the universe works: It has raised as many questions for scientists as it has answered.
STOCKHOLM – This year marks the centenary of Albert Einstein's general theory of relativity, his masterwork describing gravity as the curvature of space and time. Yet, as is often true in science, Einstein's insights have provided physicists with as many questions as they have answered.
Finding solutions that fulfill Einstein's equations – space-times that describe the curvature of our universe – is difficult, so his theory was slow to catch on. Scientists carrying out early studies and the first crucial tests were forced to use approximations. It took decades to develop techniques to classify and derive new solutions. Today, however, many solutions are known, and other thorny problems, such as the gravitational field of two colliding stars, can be explored using computers to carry out the numerical calculations.
Einstein's theory not only describes our universe, from the Big Bang to black holes; it has also taught physicists the relevance of geometry and symmetry – lessons that spread from particle physics to crystallography. But, despite the similarities that Einstein's theory has with other theories in physics, it stands apart by its refusal to fit together with quantum mechanics, the theory that explains the dominant behavior of matter at the atomic and subatomic scale.