Our universe might have 10 dimensions

We perceive the world in 3D with width, length, and height. Einstein’s relativity theory has added a fourth dimension, i.e. time, but the universe could include more dimensions, which are hidden to us. Physicists’ superstring theory, by which nature’s tiniest units are small, vibrating strings, predicts that a total of 10 spatial dimensions exist. Some think that the extra dimensions are very large and might include entire parallel universes, but that is ruled out by a new theory about the universe being based on knots. Instead, the extra dimensions must be organized in compact structures.