Chances are, the aliens will not want to land on our backyard, or even the White House lawn, with their flying saucers. They may have tiny, robotic self-replicating probes which can reach near light speed and can proliferate around the galaxy. So instead of the Enterprise and huge star ships, the aliens might actually send tiny probes to explore the universe. One might land on our lawn and we won't even know.
Michio KakuAn event horizon, or the point of no return, is only a byproduct of the bending of space. However, electricity and magnetism, by themselves, have no event horizon. It gets complicated, however, if a black hole has charge, and then this new solution does have an event horizon.
Michio KakuWormholes were first introduced to the public over a century ago in a book written by an Oxford mathematician. Perhaps realizing that adults might frown on the idea of multiply connected spaces, he wrote the book under a pseudonym and wrote it for children. His name was Charles Dodgson, his pseudonym was Lewis Carroll, and the book was Through The Looking Glass.
Michio Kaku