Gravity is not a force, as Newton and his apple would have had us believe, but a distortion of space-time. Space and time, that are intrinsically one, both curved and which can fold up upon themselves like a cosmic blanket and are capable of disappearing entirely into black holes.
Einstein’s extraordinary – and beautifully elegant – insight into this new post-Euclidian warped universe, elaborated from thought experiments, boiled down into seemingly simple equations, was enunciated for the first time 100 years ago this week to the Prussian Academy of Sciences. In doing so he turned science on its head and took over Newton’s mantle in defining the new age.
His argument – the general theory of relativity – about the nature of gravity and curvature of space-time would find some early vindication in its explanation of troublesome but important anomalies like an apparently erratic kink in the orbit of Mercury. And a proof for his contention that light would be bent by large masses would be brilliantly vindicated in 1919 by astronomer Arthur Eddington's observations of a solar eclipse. "Lights All Askew In The Heavens", read the New York Times headline.
Since then there have been black holes – to Einstein’s embarrassment – and speculation about “wormholes” that could connect seemingly distant parts of the universe, new understandings of the Big Bang which set the whole thing off, and tentative groping towards the holy grail of a so-called unified theory uniting quantum theory with gravity....
But, as the Economist observes, "Eddington's result put general relativity more or less beyond doubt. But that did not make it mainstream." Beyond doubt it is. Einstein's theory underpins much of our understanding of the structure and dynamics of the universe – mostly at the immense scale or at the smallest – but its counterintuitive logic is in reality lost to most of us. We live on in our happy Newtonian lives, understanding only a functioning approximation of the deeper truths that Albert Einstein unveiled a century ago.