New Scientist reports on the universe-as-quantum-computer:
WHAT is the universe made of? Matter or energy? Particles or strings? According to physicist Vlatko Vedral’s appealing new book, it is made, at bottom, of information.
In other words, if you break the universe into smaller and smaller pieces, the smallest pieces are, in fact, bits.
With this theme in mind, Vedral embarks on an exuberant romp through physics, biology, philosophy, religion and even personal finance. By turns irreverent, erudite and funny, Decoding Reality is - by the standard of books that require their readers to know what a logarithm is - a ripping good read.
A bit is the tiniest unit of information. It represents the distinction between two possibilities: yes or no, true or false, zero or one. The word “bit” also refers to the physical system representing that information: in your computer’s hard drive, for example, a bit is registered by a minuscule magnet whose north pole can point up or down.
Any system that has two distinct states can act as a bit - even an individual elementary particle: “electron over here” represents zero, “electron over there” represents one. When the electron goes from here to there, the bit flips.
At this smallest of scales, however, the universe is governed by the famously weird laws of quantum mechanics.