OK we know Einstien's GR is a four-dimensional theory. Time could not be
separated from space. They interact with one another. This I always
found interesting about this guy Kalusa he gave this to us. "What if"
you formulated GR in five dimensions? So he did the math and here is
what he gave us. When an extra dimension was added two sets of
equations appeared One set was Einstien's equation for gravity. The
other set was Maxwell's equation for elecromagnetism. Hmmmm
No wonder Einstien spent his last 30 years in the microscopic realm
looking for gravity's source Kaluza was very smart. Kind of makes
you think attraction of magnetisim and gravity's attraction might be two
sides to the same coin Go figure TreBert