Edward Fredkin

"Cellular automata are now being used to model varied physical phenomena normally modelled by wave equations, fluid dynamics, Ising models, etc. We hypothesize that there will be found a single cellular automaton rule that models all of microscopic physics; and models it exactly. We call this field DM, for digital mechanics."

"Under the roof of one controversial assumption about physics, we discuss five big questions that can be addressed using concepts from a modern understanding of digital informational processes. The assumption is called finite nature. The digital mechanics model is obtained by applying the assumption to physics. The questions are as follows: 1. What is the origin of spin? 2. Why are there symmetries and CPT (charge conjugation, parity, and time reversal)? 3. What is the origin of length? 4. What does a process model of motion tell us? 5. Can the finite nature assumption account for the efficacy of quantum mechanics?"

"Feynman considered Fredkin a brilliant and consistently original, though sometimes incautious, thinker. If anyone is going to come up with a new and fruitful way of looking at physics, Feynman said, Fredkin will."

"Bennett from IBM, Fredkin, and later Toffoli investigated whether, with gates that are reversible, you can do everything. And it turns out, wonderfully true, that the irreversibiilty is not essential for computation. It just happens to be the way we designed the circuits."