Computational Universe

Full Title or Meme

In trying to decide if the Universe is just a Computation on some unimaginably large computer, the similarities and differences between what we can compute on the puny digital computers tuning programs based on the Geometry of Euclid and Newton seem grossly inadequate to the job.

Context

"The failure of classical simulation of quantum systems suggests that the universe is intrinsically more computationally powerful than a classical digital computer. But what about a quantum computer"? [In the early 2000's] I showed that quantum computers can simulate any system that obey she know laws of physics (and even those that obey as yet undiscovered laws!) In a straightforward and efficient way.

Now that we are aware of the computational nature of universe as a whole, it's tempting to ascribe to it a kind of cosmic intelligence, like Laplace's divine "demon." There is nothing wrong with thinking of the universe itself as some kind of gigantic intelligent organism, any more than it is wrong to think of the Earth itself as a single living being (an idea known as the "Gaia hypothesis"). Note, however, that if you assert the intelligence of the universe, you cannot deny the brilliance of one of its greatest "ideas"-natural selection. * For billions of years, the universe has painstakingly designed new structures by a slow process of trial and error. Each "Aha" in this design process is a tiny quantum accident, whose consequences are elaborated by the laws of physics. Some accidents work out, others don't. After billions of years, the result is us, and everything else.

In the final analysis, to say that the world is alive, or that the universe thinks, is only a metaphor. After all, what are these thoughts of the uni- verse? Some of the information processing the universe performs is indeed thought-human thought. Some of that information processing, like digital computation, can resemble thought. But the vast majority of the information processing in the universe lies in the collision of atoms, in the slight motions of matter and light.

Compared with what is normally called thought, such universal "thoughts" are humble: they consist of elementary particles just minding their own business. But humility is not the same as weakness. Quantum chaos can amplify slight motions until they become a hurricane. The microscopic dance of matter and light had the power to produce not just human beings, but every being. The collision of two atoms can-and does-change the future of the universe. (P. 211)

References

Other Material

• See wiki page on Eventful Universe