Quantum wormholes could carry people
- All around us are tiny doors that lead to the rest of the Universe.
Predicted by Einstein's equations, these quantum wormholes offer a
faster-than-light short cut to the rest of the cosmos - at least in
principle. Now physicists believe they could open these doors wide
enough to allow someone to travel through.
Quantum wormholes are thought to be much smaller than even protons
and electrons, and until now no one has modelled what happens when
something passes through one. So Sean Hayward at Ewha Womans
University in Korea and Hisa-aki Shinkai at the Riken Institute of
Physical and Chemical Research in Japan decided to do the sums.
They have found that any matter travelling through adds positive
energy to the wormhole. That unexpectedly collapses it into a black
hole, a supermassive region with a gravitational pull so strong not
even light can escape.
But there's a way to stop any would-be traveller being crushed into
oblivion. And it lies with a strange energy field nicknamed "ghost
radiation". Predicted by quantum theory, ghost radiation is a
negative energy field that dampens normal positive energy. Similar
effects have been shown experimentally to exist.
Ghost radiation could therefore be used to offset the positive
energy of the travelling matter, the researchers have found. Add
just the right amount and it should be possible to prevent the
wormhole collapsing - a lot more and the wormhole could be widened
just enough for someone to pass through.
It would be a delicate operation, however. Add too much negative
energy, the scientists discovered, and the wormhole will briefly
explode into a new universe that expands at the speed of light, much
as astrophysicists say ours did immediately after the big bang.
For now, such space travel remains in the realm of thought
experiments. The CERN Large Hadron Collider in Switzerland is
expected to generate one mini-black hole per second, a potential
source of wormholes through which physicists could try to send
But sending a person would be another thing. To keep the wormhole
open wide enough would take a negative field equivalent to the
energy that would be liberated by converting the mass of Jupiter.