## Einstein’s Magnum Opus

*By David Roberts*

One hundred years ago this month, Albert Einstein unveiled one of mankind’s greatest intellectual accomplishments – his General Theory of Relativity, our current understanding of gravity. Not only did it transform the way we look at space and time, but, unique among modern science theories, it was largely the work of one man’s towering genius.

Before Einstein, heavenly bodies and earthly projectiles alike seemed to move to Isaac Newton’s gravitational laws. Though Newton was not fully satisfied with his theory, which lacked an explanation for how gravity exerts its force, it had withstood centuries of observation. However, in the 19^{th} century, cracks began to appear. Data emerged showing that Mercury’s orbit deviated slightly from Newton’s predictions, which led the French astronomer Le Verrier to predict (incorrectly) a new planet, Vulcan, to explain the discrepancy. A more damning blow came in 1905 when Einstein and others showed that information propagates at a finite speed, refuting Newton’s theory of gravity which required instantaneous influences over unlimited distance.

It took Einstein almost a decade to resolve this apparent paradox. He was able to develop a new theory of gravity and how it works based on a newly developed geometry of curved spaces, as well as Einstein’s own deep insight that feeling the pull of gravity is not fundamentally different from feeling accelerated. (Actually, German mathematician David Hilbert technically might have written down the equations a couple of days earlier, but most – including Hilbert – agreed that this *tour de force* was Einstein’s.) He argued that gravity arises from warped space and time, as how a tennis ball is drawn towards a bowling ball if both are placed on the surface of a trampoline. Not only did it accurately explain Mercury’s —> Read More