Physicists are increasingly entertaining a radical possibility: our familiar universe of three dimensions of space and one of time might be only part of a larger structure, with a hidden fifth ...

Physicists are quietly testing wild new theories that treat a hidden fifth dimension as more than science fiction, suggesting it could steer how gravity, dark matter and even cosmic history unfold.

The Standard Model of our universe doesn’t match the evidence, in part because of dark energy, a ghostly force pushing the universe apart. Now some researchers think our universe might be moving into ...