According to string theory, hypothetical shortcuts through spacetime called wormholes, might well exist in our Universe.

For those of you who wouldn’t be Stargate fans, wormholes would be “tunnels” between two different locations in the Universe (they could also allow to travel in time, or to parallel universes). Basically, while it would normally take millions or even billions of years to go to a remote destination, a wormhole would allow you to go there in a handful of seconds.

Wormholes appeared as mathematical solutions to the Einstein field equations, and they’ve never been observed (a mathematical possibility is not necessarily a physical reality).

After some research had been done on the topic, it occurred that if wormholes did exist, they would be useless anyway: as soon as it comes to life, a wormhole vanishes. In order to sidestep this “problem”, Kip Thorne and Mike Morris imagined that a new form of matter, known as exotic matter, could keep a wormhole open and stable. The annoying detail is that exotic matter, which has a negative mass, is even more hypothetical that wormholes themselves…

© Burkhard Kleihaus and Jutta Kunz

Now, string theory is tackling the problem of wormhole’s existence. Indeed, it seems that string theory can make stable wormholes, without any addition of exotic matter. I’m not going to make a course on string theory, it would be too long and too complicated… In a few words, it postulates that the building blocks of the Universe are not point particles, but vibrating strings: everything we observe as distinct particles would actually be the same strings vibrating differently. String theory was born from the necessity to give a quantum description of gravity (in order to unify quantum theory and relativity), and it also claims to be a contender for the Theory of Everything, unifying all known interactions in a quantum mechanically consistent way.

According to Panagiota Kanti from University of Ioannina, Greece, Burkhard Kleihaus and Jutta Kunz from University of Oldenberg in Germany, if the corrections of string theory are taken into account, wormholes can exist without any exotic matter to keep them open. The researchers also add that these wormholes can be “arbitrarily large”, that is big enough for something to make its way through.

So, does that mean we can hope that someday we’ll wander in the Universe a la SG1? Probably not… Actually, the problem with string theory is that you can do almost anything with it… Seriously. String theory advocates will argue that their theory is mathematically complete or “beautiful”… Maybe, but at the time being, the whole theory is just unverifiable… All this, for now, is only pure speculation…