There was a blithe certainty that came from first comprehending the full Einstein field equations, arabesques of Greek letters clinging tenuously to the page, a gossamer web. They seemed insubstantial when you first saw them, a string of squiggles. Yet to follow the delicate tensors as they contracted, as the superscripts paired with subscripts, collapsing mathematically into concrete classical entities-- potential; mass; forces vectoring in a curved geometry-- that was a sublime experience. The iron fist of the real, inside the velvet glove of airy mathematics.
Gregory Benford - Timescape