A new study has played down fears that wormholes would not be stable enough.
It might sound like science fiction, but the idea of linking two black holes together actually does have some merit.
Scientists have put forward the possibility that what we think of as a black hole may be something else entirely.
If a wormhole stayed open long enough it may be possible to send messages back and forth through time.
A mind-bending new theory suggests that black holes are actually wormholes to alternative universes.