Metaphysics and Relativity

According to SR, Newton was more-or-less right about how objects move at ordinary speeds: that’s why his theory was successful for so long, and why it continues to be useful. But SR comes into its own when accounting for the surprising behaviour of objects moving near the speed of light (300 000 kilometres per second, or 186 000 miles per second). Despite ignoring gravity, SR in its turn is usually successful: this is because, as GR tells us, over shortish distances gravity has much less influence than other forces. But GR comes into its own when accounting for the surprising nature of the universe on the grand scale, where local forces become negligible, and gravity is crucial.