Two Israeli scientists appear to have found out that if anyone tried to use a black hole this way they would be ripped apart.

A black hole is an object from which light cannot escape. It can be the extremely dense remains of a collapsed star.

Professor Stephen Hawking and Sir Roger Penrose showed that inside every black hole there is always a thing that scientists call a "singularity".

Here matter and also space and time is condensed to a point. The normal laws of physics break down.

Black hole: incredibly powerful

Some scientists have speculated that under certain conditions such a singularity might be a tunnel across the universe.

If it was possible to go through the hole in a spaceship you could jump across the universe in an instant, or even emerge in a completely different universe.

Ripped to shreds

Tsvi Piran and Shahar Hod of Jerusalem's Hebrew University used computers to simulate both how a black hole forms and how the singularity behaves.

The simulations showed that an electrically charged black hole creates a new kind of singularity which forms an impassable barrier.