The document discusses the idea in theoretical physics that there may be more than three spatial dimensions. Many physicists now believe this could help explain and unify fundamental forces and particles. Originally proposed in the 1920s, theories with extra dimensions beyond our everyday experience could give rise to forces like electromagnetism from higher-dimensional gravity. Modern string theory also requires the existence of 6 or 7 additional dimensions. If extra dimensions exist, they would have to be small enough to have avoided detection so far. Finding evidence of extra dimensions could help geometrize our understanding of physics.