The ultimate computer

摘要

It makes a Pentium chip look like an abacus. But it's not a military supercomputer or colossal number cruncher. This computer was booted up at the big bang and has been running for 13 billion years. Yes, it's the Universe. Scientists know that a single fundamental particle such as an electron or a photon will carry a single bit of information, and that they can perform calculations with the information by manipulating the particle. Researchers are trying to build quantum computers to do just that (see p 21). Such devices would be far more powerful than conventional computers. But how powerful could they be?