On Wolfram’s «natural» computers
Are typical systems that we encounter in nature universal? Or are they
computationally much simpler?
Can we expect to find non-trivial computational behavior just by searching a
space of possible systems? Or can we only reach such behavior by
specifically setting it up, say using traditional engineering methods?
Wolfram’s questions are meaningful only if universal realizability (i.e., the claim that anything can be described as implementing a computer program) is indeed true. However, no one has proved that universal realizability is indeed true. Not to mention that many men and women do not believe that rocks or desks do compute something.