After developing general relativity, which provided an explanation for the gravitational force, Einstein spent the rest of his life unsuccessfully searching for a theory of everything: a single theory that would explain the four fundamental forces of the universe–gravity, electromagnetism, and the two nuclear forces. Einstein may not have succeeded, but finding this unified field theory became the holy grail of physics, and one of the most promising attempts in this quest is string theory.
String theory suggests that there are other dimensions beyond the three spacial dimensions (plus time) we experience in everyday life. These additional dimensions are invisible to us and, in most versions of string theory, they are thought to be infinitesimally small and curled up in every point of the three-dimensional universe we perceive. But recent theories suggest that at least one of these additional dimensions may be quite large, and that our universe is like a membrane embedded within this hyperspace.
Kip Thorne, Feynman Professor of Theoretical Physics, Emeritus, at Caltech, explains the mind-boggling concept of hyperspace and how our universe may be like a membrane embedded within it.
Fusion’s original Relatively Speaking series celebrates the 100th anniversary of Albert Einstein’s general theory of relativity.