"Pondering about the problem, Einstein thought about the beam of light curving around the limb of the sun; he soon realized that it was not the beam that was bent, but rather the space through which it traveled. Matter must somehow curve space and other matter must move through this curved space in the way we see it move—yet this way must be "natural." He decided the most natural way would be along a path that represented the shortest distance between two given points in space (this is called the geodesic in mathematics). This would mean that the sun curves the space around it and the planets move in this space along geodesics. These geodesics appear to us to be elliptical orbits, but in curved space they are actually straight lines."