Large Extra Dimensions

A radical solution to the Hierarchy Problem proposed by theorists like Nima Arkani-Hamed, Savas Dimopoulos, and Georgi Dvali. It posits that the weakness of gravity relative to the other forces is an illusion. Gravity only appears weak because it is not confined to our 3-dimensional "brane" of spacetime like the other forces are; it can propagate into additional, macroscopic spatial dimensions. These dimensions could be as large as a fraction of a millimeter, a scale just beyond current experimental reach. This "dilution" of gravitational flux across more dimensions explains its feebleness. A dramatic prediction is that at very small distances (high energies), gravity would become strong, and microscopic black holes could be produced in particle colliders, opening a direct window into quantum gravity and revolutionizing our understanding of the fundamental scales of nature.