Original spin

摘要

Albert einstein was right about many things. The universe was not one of them. To him, as to many before him, the cosmos was a static, unchanging entity. In 1915, on deriving his equations of general relativity and discovering that the universe they described did not work like this, he added in an extra term to make sure that it did. Whoops. A decade later, observations of nearby galaxies revealed that the universe is far from static, but has expanded furiously since its birth in an infinitely hot, dense fireball billions of years ago: the big bang. That's not all. In the 1990s, light from distant supemovae convinced us that the universe's expansion is accelerating. That was posthumous luck for Einstein: the fudged term in his equations was revived to describe a "dark energy" fuelling that acceleration. So the universe is both expanding and accelerating. Fine. Now, though, hold on to your hats - it might be spinning, too.