A new way to visualize General Relativity

Caption notes

ScienceClic starts with the familiar elastic-sheet picture and points out that explaining gravity with a marble rolling downhill already relies on gravity outside the sheet. The narration offers a thought experiment instead: two ants heading north on a sphere can each keep going straight ahead and still meet at the North Pole. The example shows how geometry can change the relationship between neighboring paths. The video also points out how easily the elastic-sheet picture leaves out the time dimension.