From Fox News,
Through the Cosmic Looking Glass
7.00 a.m. ET (1100 GMT) November 10, 1999
England, 1871 — Lewis Carroll's Alice goes through the looking glass and physicists all over the world are ready to follow. Lewis Carroll dreamt of a little girl who goes through a mirror and enters a world inhabited by chessboard characters. Fifty years later physicists also imagined a universe filled with intriguing characters: white dwarfs, red giants, black holes.
Alice at the edge of the wormhole to Wonderland
There's only one way Alice could have left our world for another hidden behind an ordinary mirror. She must have gone through a wormhole. That is, there must have been a miniature Black Hole on the surface of the looking glass that sucked her in and then a White Hole on the other side that spewed her out.
A Black Hole can be imagined as an ordinary sink painted black with a drain sucking anything leaning too close to its edge into an invisible universe. A White Hole, as its name indicates, is the reverse of a Black Hole: a white sink turned upside down into which nothing can fall, only fall from. Connecting these two appliances is an Einstein-Rosen bridge — the plumbing — what is popularly referred to as a wormhole.
The main problem with Alice going through a wormhole
on the surface of a mirror, is that it breaks the rules of the game. And
the rule here is the second law of thermodynamics, namely that when an
event takes place it cannot be undone without effort. For example, to return
the grounds behind the looking glass to their original state after the
Red Queen's tea party, someone is going to have to do some work. This seemingly
obvious statement means that time
is not reversible for large-scale events.
Stabilizing a wormhole with exotic matter
Since a White Hole reverses
the events of its nemesis effortlessly, it goes contrary to the second
law of thermodynamics. The game must be played according to the rules,
but physicists are still figuring these out. At the
center of a Black or a White Hole, for instance, lays a singularity: a tangible location with mass and zero volume, and thus infinite density.
Even the wormhole connecting either side of the looking glass is not a safe gateway. It is highly unstable and can quickly collapse into a singularity as well. In fact, a spaceship approaching a wormhole would be accelerated by the large gravitational field (of the Black Hole) and start emitting what are called gravitational waves — a bit like a moving speedboat creates waves in the surrounding water. These waves would disrupt the wormhole's stability and cause it to collapse.
A creative scientist, however, might keep a wormhole's throat open by using a trick: filling the Einstein-Rosen bridge with matter that would have negative mass and gigantic outward pressure. The gravitational field of a negative mass would be repulsive, instead of attractive, thus prying the wormhole open. The gigantic outward pressure (thousands of times that at the surface of a neutron star) would keep the tunnel from collapsing.
At this point I should mention this solution is rather controversial (to say the least). It is difficult to figure out what is and is not "strictly in accordance with the laws of the game." For example, time is in fact reversible on microscopic levels, such as when particles are created and annihilated to create energy. This is observed in accelerators around the world. So traveling through a wormhole may be possible for subatomic particles.
On the other hand, there is no exotic matter that we know of with negative mass. So there seems to be no way to connect either side of Alice's mirror — if it has two sides.
From the co-evolutionary point of view, past and present seem to exist together in a higher-dimensional reality we call the future."
- Dr's Briggs and Peat - _The
Looking Glass Universe_