Thursday, April 15, 2010

Heavy Lifting: The Biggest Question?

There are ideas are light and easy to understand. Others require more thought and are harder to follow. Heavy lifting may be required.
There are a number of very big questions. Fundamental questions about ourselves. To badly paraphrase Douglas Adams' whale who finds itself suddenly called into existence several miles about the surface of an alien planet:
Ah ... ! What's Happening? Er, excuse me, who am I? Hello? Why am I here? What's my purpose in life? What do I mean by who am I? ...
The question of who we are and why are we here is a big one. Maybe not the biggest though. There may be an even more fundamental question. A question that starts with an observation about our universe.

If the universe obeys rules then is what happens pre-ordained or in flux? And even if some of the rules, let's use quantum mechanics as an example, make some parts of the universe unpredictable, what are the implications to the biology, chemistry, and physics that are happening in our brains?

The practical version of the question is this: Does Free Will Exist?

My own semi-humorous answer has always been that "Of course we believe in free will. It's our destiny."

The question is much deeper than any smug answer. Great minds have tried to figure out if free will exists or not. I recently watched one of the great minds of our time work out a new take on the problem. John Conway may be most famous as the mathematician who created Conway's Game of Life but he's worked in many areas of math from group theory to algebra, from geometry to topology.

He doesn't so much prove that free will exists. Instead he shows that if an experimenter has free will when performing a certain physics experiment then the elementary particles that are in the experiment also have free will to chose the outcome of the experiment.

As he puts it "if experimenters have free will, then so do elementary particles."

He and his co-author Simon Kochen published the initial version of the proof in 2006 as The Free Will Theorem in the journal Foundations of Physics. In 2009 they published follow up called The Strong Free Will Theorem (pdf) in the Notices of the AMS. The Strong version extends the proof further.

The proof on paper is dense, filled with math, and would have been almost impossible for me to follow if I hadn't first watched a series of lectures he gave that that explained the proof step by step.

The lectures where given in 2008 at Princeton and are online:
  1. Free Will and Determinism in Science and Philosophy
  2. The Paradox of Kochen and Specker
  3. The Paradoxes of Relativity
  4. Quantum Mechanics and the Paradoxes of Entanglement
  5. Proof of the Free Will Theorem
  6. The Theorem's Implications for Science and Philosophy
Personally I tend to be skeptical of people who use quantum mechanics and the paradoxes of science to 'solve' deep mysteries of the universe. The number of pseudo-scientific crackpot theories out there is immense. John Conway does not solve a deep mystery of the universe, instead he forces us to extend our concept of choice and free will. John Conway's previous work and history as a rational thinker moves this theory from "a cooky idea" to "something to take very seriously".

Now I do have a few issues with the proof. I don't think my issues disprove the theorem. I just think there are areas in which the explanation is a bit lacking. In particular around his use of what he calls the spin axiom. My questions are logical extensions to his line of reasoning. Logical extensions he doesn't explain or follow through with fully. It's not a disagreement, it's more that there is part of the proof I'd like explained or explored a little more.

Don't think my minor issues lessen the beauty and simplicity of the overall theorem. It is a tour de force. For me there are two moments in particular that are mind expanding.

First is when he takes the spin axiom and visually shows that it can lead to paradoxical situations. Instead of complex math or set theory he shows the underlying problem visually. It's much easier to follow along and understand than any set of symbols on paper.

Secondly the theorem brilliantly shows how the 'free will' of an elementary particle is not based on anything that has happened before. It turns out that the past is irrelevant in the scenario that is put forth. The decision is removed from anything that can be considered predetermination.

The concepts, the math, the results, and the implications are not easy to grasp. Then I don't expect that any of the big questions are easy to tackle. If you have the time, and you put in the effort, the lectures are surprisingly rewarding and definitely worth watching.

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