Quantum Virtual Reality

In films like The Matrix and books about futuristic societies like the Culture of Iain M Banks, the characters pass back and forth into a virtual reality universe, where everything is just an illusion. Reality is just information in a computer world fooling their senses. Turns out the real universe could actually just be a computer too if a new theory of the universe from the theoretical physicists is right.

Physicists have long been searching for a "theory of everything" - basically a single mathematical way of describing reality so that space, time, the properties of particles like electrons and neutrinos, gravity - in fact everything - then follows as a consequence. At the moment physicists have a series of separate theories each of different parts of reality: like Einstein's Theory of relativity. Finding a way to fit all the theories together was something that even Einstein struggled with.

The latest attempt at a theory of everything is called "loop quantum gravity". It starts from Einstein's theory of relativity and the idea that everything is built from a network of relationships that can be tied in tangles. Particles are just the tangles.

One of the wilder possibilities that emerge from this is that space might actually be made up of a web of information - a bit like in a virtual world like the Matrix - and the universe is then just a giant computer: not a traditional computer as we currently use but a kind of quantum computer.

Quantum computers may be the future of computing. Traditional computers store information as bits: 1s or 0s. Quantum computers store qubits: bits that can be both 1 and 0 at the same time. If we can develop computers that work in this way they will be vastly more powerful than current ones.

The theory of quantum loop theory is quite promising so far in that starting from relativity alone it has given a description of both space-time and particles that correspond to reality. There is a long way to go to be sure it can really describe everything. That's where the practical science has to start. Good scientific theories are testable. The theory needs not only describe reality as we know it but predict some new things that experiments can be set up to test. If it passes the tests then Douglas Adams in the Hitch Hikers Guide to the Galaxy may not have been so far wrong. Though rather than the Earth being a computer trying to work out the question to the answer of life the universe and everything. The answer itself may be that the whole universe is a quantum computer.