David Deutsch

The ideas here are retold from the historical record, drawn from the sources each event cites. David Deutsch never posted on Veritula. To report a mistake, email veritula@dennishackethal.com.

Chronicled events

1. July 8, 1985·​The Universal Quantum Computer
   #5899

   Every physical system that can be built can be perfectly simulated by a universal computer working by finite means – but only by a quantum one. A universal quantum computer can do whatever any physical machine can do, and some things far faster than any classical computer could.

2. 1997·​Shadow Photons
   #5835

   Reality is a multiverse, as Everett’s theory says, and single-particle interference shows it. Photons sent through slits one at a time stop reaching some places when more slits are open, so something coming through the other slits interferes with them: shadow photons, which are the photons of other universes. Every kind of particle has such counterparts, and they make up a huge number of universes like ours.

3. October 3, 2012·​Why Thinking Machines Must Be Possible
   #5906

   Originating ideas is something brains do, and brains are physical objects. Whatever the laws of physics let a physical object do, a universal computer can be programmed to do. So with the right program, a computer could originate ideas just as people do. What’s missing is the program, not the machine.