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Sand in the Brain: A Fundamental Theory To Model the Mind
An anonymous reader writes "In 1999, the Danish physicist Per Bak proclaimed to a group of neuroscientists that it had taken him only 10 minutes to determine where the field had gone wrong. Perhaps the brain was less complicated than they thought, he said. Perhaps, he said, the brain worked on the same fundamental principles as a simple sand pile, in which avalanches of various sizes help keep the entire system stable overall — a process he dubbed 'self-organized criticality.'"
The pendulum regarding self-organized criticality is beginning to swing back in the other direction: many researchers now believe it's being over-applied, and the "power law" distributions that people see for natural phenomenon that are "evidence" of S.O.C. have been shown to not actually obey power laws (it's really easy to make these kinds of mistakes when you make your graphs on log-log scales). Sorry if that was a bit dense, but the long and short of it is that not everything that is being touted as an example of self-organized criticality likely is. For instance, the Bak–Tang–Wiesenfeld sandpile (Bak being the one from TFA)? Turns out it's a HORRIBLE model for how real sandpiles behave.
A lot of the above really needs citations, but I'm too tired and lazy, sorry. To "back this up," let me just say that I have a Ph.D in physics, specializing in nonlinear dynamics, and the above comes from a graduate-level course I took from a professor who knows her shit.
Except we are seeing many cases where it is counterintuitive even to working scientists in their own fields, just which explanation is simpler.
For example, Guth's inflationary hypothesis in Cosmology has resulted in a prediction that certain constants must be random (because otherwise, there's the implication of something we might as well call God behind the non-random values). A hypothesis that invokes God is probably not the most simple - anything that might merit the name of God is likely to be more complex than the very universe it 'explains'. Fair enough, but random values seem to imply an infinity of parallel universes, which however will never be detected by real science, only in science fiction. An infinity of untestable phenomina as the outcome of a model hardly makes that the preferred model by Occam either. Last I looked, neither one of these interpretations of the inflationary hypothesis* has been mathematically shown to be the more simple of the two. If people who have had some real impact on the specific field (i.e. Hawking), can't really agree on what they mean by simple, Occam's Razor isn't working very well.
This has shown up in several other areas of science, for example recent math proofs by computer that are so complex there's a real chance the computer made errors during the months it was crunching numbers for the millions of steps required. Once a proof is too complex for humans to even check, how can we possibly tell whether it is more complex than another proof or not? (Counting lines of code is not a very good measure there). And while I'm hardly up on all the issues in the "universe as a giant computer" debate, I've seen arguments from some of the pros in that field that seem to show there's problem with determining which explanations are the most simple there too, and I've heard at least one working scientist in the field of sexual selection pressure complain about the same thing.
* The recent Antarctic discovery might argualbly elevate Cosmic Inflation from hypothisis to full fledged theory if it wasn't there yet. For those who think it was a theory already, these observations would seem to place it on even more solid ground, in much the same way as Crick and Watson's work helped strengthen the claim of Evolution to be a well tested and heavily supported theory. But, not being able to predict whether the initial universal constants were random or non-random is a real problem when it comes to proclaiming Cosmic Inflation has the status of a solidly tested theory, no matter how much other evidence scientists gather.
Who is John Cabal?