The reductionist blind spot:

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The reductionist blind spot:. three examples. Russ Abbott Department of Computer Science California State University, Los Angeles. Living matter, while not eluding the ‘laws of physics’ … is likely to involve ‘other laws,’ [which] will form just as integral a part of [its] science. - PowerPoint PPT Presentation

Text of The reductionist blind spot:

  • The reductionist blind spot:Russ AbbottDepartment of Computer ScienceCalifornia State University, Los Angelesthree examples

  • Living matter, while not eluding the laws of physics is likely to involve other laws, [which] will form just as integral a part of [its] science. Why is there anything except physics? Fodor[Starting with the basic laws of physics] it ought to be possible to arrive at the theory of every natural process, including life, by means of pure deduction.All of nature is the way it is because of simple universal laws, to which all other scientific laws may in some sense be reduced. There are no principles of chemistry that simply stand on their own, without needing to be explained reductively from the properties of electrons and atomic nuclei, and there are no principles of psychology that are free-standing.[Starting with the basic laws of physics] it ought to be possible to arrive at the theory of every natural process, including life, by means of pure deduction. Einstein Living matter, while not eluding the laws of physics is likely to involve other laws, [which] will form just as integral a part of [its] science. Schrdinger.All of nature is the way it is because of simple universal laws, to which all other scientific laws may in some sense be reduced. There are no principles of chemistry that simply stand on their own, without needing to be explained reductively from the properties of electrons and atomic nuclei, and there are no principles of psychology that are free-standing. Weinberg The ability to reduce everything to simple fundamental laws [does not imply] the ability to start from those laws and reconstruct the universe. The ability to reduce everything to simple fundamental laws [does not imply] the ability to start from those laws and reconstruct the universe. Anderson Why is there anything except physics? Fodor

  • Why wont a square peg fit into a round hole?If a square peg can be reduced to the elementary particles that make it up, why cant those particles fit through a hole of any shape?Because its shape isnt compatible with the shape of the hole.Common sense. Right?First example

  • Is it quantum mechanics or solid geometry?Describe a particular square peg and a particular round hole by characterizing the positions of the elementary particles that make them up.Will be very different depending on materials: metal, glass, wood, .Argue that the forces among particles when in a "peg" and "hole" configuration require them to satisfy various invariants: the geometric relationships among the peg particles are fixed (it doesnt change shape); the hole has rotational symmetry.Conclude that the forces, invariants, and symmetries prevent the particles that represent the peg from moving to a position that would be described as being in the hole created by the round hole particles.A similar argument must be made for each peg-hole combination.Quantum mechanics

  • Is it quantum mechanics or solid geometry?Describe the abstract geometrical characteristics of square pegs and incompatible round holes, namely that the diagonal of the face of the square peg is greater than the diameter of the round hole. Solid geometry is a level of abstraction. Discussed further later.If we require that non-interpenetrable solids do not intersect, we can conclude that any (abstract) square-peg/round-hole pair with incompatible dimensions will not fit one within the other.Whenever nature constructs entities that instantiate such solid geometry abstractions, they too will not fit one within the other.Solid geometry

  • Is it quantum mechanics or solid geometry?Is solid geometry reducible to physics? Is solid geometry just a convenient generalizationsomething that captures multiple physics cases in a convenient package?Or is it an independent domain of knowledge?My answer is that its an independent domain of knowledge. But this example may seem somewhat borderline.The more basic question is whether the square peg and round hole are ontologically real entities and if so whether reducing them away loses anything. My answers: They are ontologically realfor a number of reasons.Reducing them away loses something. One loses both the entities themselves and the theorysolid geometrythat describes how they behave. Reducible or not?

  • Similar arguments forThe theory that explains how an atom at the end of my nose got from LAX to Indianapolis.Im an entity; the airplane is an entity.We are governed by laws from Newtonian physics and aerodynamics.The trajectory of Roger Sperrys nail on the rim of a wheel.The wheel is an entity governed by laws from Newtonian physics and plane geometry.

  • Turing machines and the Game of Lifehttp://www.ibiblio.org/lifepatterns/Second example

  • Is this attributable to the Game of Life rules or to computability theory?I cant think of an argument that attributes GoL undecidability to the GoL rules. There may be a direct argument, but the only obvious argument is to construct a TM and argue from computability theory?Yet reductionism holds! The GoL rules control everything that occurs on a GoL gridjust as fundamental physics controls everything that happens in our world. But computability theory is independent ofand was even developed prior tothe GoL.

  • Is this attributable to the Game of Life rules or to computability theory?The undecidability of the TM halting problemand hence of the GoL halting problemis a consequence of computability theory, not of the GoL rules.When a GoL configuration implements a Turing machine, computability theory applies to that implementationand hence to the universe in which the implementation occurs.Again, isnt this just common sense?

  • The same argument was used for both the TM and the pegs and the holesTrue for pegs and holes made from electrons, protons, and neutrons.True for Turing machines made from GoL patterns.If I build something thats governed by a special theoryi.e., something that realizes an abstraction that is governed by that theorymy constructioni.e., my implementation of the abstractionis governed by that theory.In both cases the constructed entity follows the rules that govern the abstraction it implements.Raises the question: what is an entity?The lower-level rules determine whether one can build an instantiation of the abstraction at alland if so how.

  • The same argument was used for both the TM and the pegs and the holesTrue for pegs and holes made from electrons, protons, and neutrons.True for Turing machines made from GoL patterns.If I build something thats governed by a special theoryi.e., something that realizes an abstraction that is governed by that theorymy constructioni.e., my implementation of the abstractionis governed by that theory.In both cases the constructed entity follows the rules that govern the abstraction it implements.Raises the question: what is an entity?The lower-level rules determine whether one can build an instantiation of the abstraction at alland if so how.

  • Is this strange?The unsolvability of the TM halting problem entails the unsolvability of the GoL halting problem.We import a new and independent theory into the GoL world and use it to draw conclusions about the GoL.Downward causation entailmentDownward causationGoL Turing machines are causally reducible but ontologically real.You can reduce them away without changing how a GoL run will proceed.Yet they obey higher level laws, not derivable from the GoL rules.Reducing everything to the level of physics, i.e., nave reductionism, results in a blind spot regarding higher level entities and the laws that govern them.This is called reduction in Computer Science. We reduce the question of GoL unsolvability to the question of TM unsolvability by constructing a TM within a GoL universe.

  • EvolutionThe theory of evolution is about biological entities.How would one use quantum physics to explain the biological entities that we see around us?Even if we assume that its (theoretically) possible to trace how any state of the worldincluding the biological organisms in itcame about by tracking elementary particles, it is not possible to express the theory of evolution in terms of those particles.It is not possible to characterize a biological entity in terms of elementary particles.It is not possible to describe the evolutionary processdifferential survival and reproduction of biological entities along with combination and mutation of inherited propertiesin terms of elementary particles.Reducing everything to the level of physics, i.e., nave reductionism, results in a blind spot regarding higher level entities and the laws that govern them.Third example

  • Level of abstraction: the reductionist blind spotA collection of concepts and relationships that can be described independently of its implementation.Every computer application creates one.A level of abstraction is causally reducible to its implementation. You can look at the implementation to see how it works.Its independent specificationits properties and way of being in the worldmakes it ontologically real.How it interacts with the world is based on its specification and is independent of its implementation.It cant be reduced away without losing somethingA concept computer science has contributed to the world.

  • Abstract data types

  • Backups

  • How are levels of abstraction built?By adding persistent constraints to what exists.Constraints break symmetry by limiting the possible transformations. Symmetry is equality under a transformation.Easy in software. Software constrains a computer to operate in a certain way.Software (or a pattern set on a Game of Life grid) breaks the symmetry of possible sequences of future states. A constrained system operates differently (has additional lawsthe