General Relativity. David Berman Queen Mary College University of London. Geometry. In the previous lecture we saw that the important thing was to have an invariant quantity (the distance in spacetime).
Queen Mary College
University of London
To understand geometry we need to understand what makes a straight line on a curved space.
A straight line between two points is given by the shortest distance between those two points along the curved surface.
One can work out how all the other geometric properties.