IT鈥橲 bad news for Star Trek fans. Black holes, which physicists
believed could allow future civilisations to tunnel to far-flung regions of the
Universe or even to other universes, appear to be useless for such intergalactic
travel, Israeli scientists have shown.
Einstein鈥檚 general theory of relativity describes space and time as a
flexible fabric which the gravitational pull of an object can warp. In a black
hole鈥攖he superdense remains of a collapsed star鈥攖he gravity is so
enormous that it can be likened to a hole in the fabric of space-time
itself.
快猫短视频s have speculated that if you could go through the hole in a
spaceship, you would jump halfway across the Universe in an instant, or even
emerge in another universe. But others argued that a black hole鈥檚 gravitational
pull is so great that a spaceship would never escape from its grasp. Worst of
all, anyone entering a black hole would slam into a 鈥渟ingularity鈥�, a point where
the bending of space-time becomes infinite and all matter is torn apart.
Advertisement
But several years ago, physicists found a way round this. They speculated
that a spinning or an electrically charged black hole might have a stretched-out
singularity in the shape of a ring. In theory, a spaceship could fly through the
ring without getting shredded. 鈥淚t allows the observer to fall into a black hole
and fly through it, and emerge nobody knows where,鈥� says Nickolay Gnedin, an
astrophysicist at the University of Colorado at Boulder.
But now Piran and his colleague Shahar Hod have scuppered this idea. They
used computers to simulate both how a charged black hole forms from the remains
of a star and how the singularity behaves鈥攖he first time that a single
computer program has simulated these two processes at once.
The simulations showed that the formation of a black hole creates a new kind
of singularity due to an effect called 鈥渕ass inflation鈥�. When a traveller moves
towards the black hole, the apparent mass of the hole increases to infinity. So
in the end, the traveller would indeed be ripped to shreds (Physical Review
Letters, vol 81, p 1554). 鈥淭his singularity goes through the entire
system,鈥� says Piran. 鈥淚t doesn鈥檛 leave any hole through which matter may
辫补蝉蝉.鈥�
鈥淚t鈥檚 quite an amazing piece of work,鈥� says Eric Poisson, an astrophysicist
at the University of Guelph, Ontario. 鈥淭here鈥檚 no way to go through if the
singularity really is a brick wall.鈥�