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A New Kind of Science in a Nutshell. David Sehnal QIPL at FI MU. Motivations. How does anything complicated get produced in nature? Traditional Science – i.e. calculus, Newtonian physics, … What if there is a more general underlying principle? Simple programs. 1D Cellular Automata.
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A New Kind of Sciencein a Nutshell David Sehnal QIPL at FI MU
Motivations • How does anything complicated get produced in nature? • Traditional Science – i.e. calculus, Newtonian physics, … • What if there is a more general underlying principle? • Simple programs
Cell to be updated Left neighbor Right neighbor New color
This type behavior is very surprising • Started from a single black cell • Used simple rules • Got something that looks to us completely random
To sum it up… • Simple rules do not imply simple behavior • It seems that complex behavior is a very common phenomenon
Snowflakes • When a piece of a snowflake solidifies, heat is released • This heat prohibits ice nearby • New rule: Piece solidifies if exactly on of the neighborhood cells is solid
More systems in nature • Fluid flow • Patterns on shells • Fundamental physics • And many others …
Computation • All cellular automata can be though of as doing computations • One does not need to know the point of the computation beforehand
Universality • Some automata can simulate all others • One only needs to specify the initial conditions
Universality • Once universality is reached, the behavior is maximally sophisticated (from the computational point of view)
More questions • What about systems such as rule 30? • Or systems in nature? • How sophisticated are these?
Principle of Computational Equivalence Essentially any time the behavior of a system looks to us complex, it will end up corresponding to a computation of exactly equivalent sophistication.
Simple behavior (repetitive or nested) corresponds to simple computations • Complex behavior corresponds to sophisticated computations
Threshold of Universality • Rule 110 is universal