Video of Einstein's general theory of relativity: the essential idea | Britannica

A simplified introduction to Einstein's theory of relativity

The fourth dimension, as described by Albert Einstein, is an intangible dimension like the first three dimensions, “length, width and height.” Rather, it is a curvature of spacetime as he describes it. As a quick example, for example, since the fourth dimension is time, my friend, you are walking on a road that has a certain height, length and width as well, and the time you travel is the fourth dimension. The point that determines your location is added to time and becomes as follows: (x, y, z,

Fourth Dimension | Definition, History & Examples