Ferromagnetism and the Brain

What does the fact that a piece of iron loses its magnetism above the Curie temperature (1043 F) have to do with the brain? The electrical activity of neurons does create extremely weak magnetic fields and the activity can be affected by extremely strong magnets. The latter effect is sometimes used by experimenters to modify ongoing brain activity, but the reason why we study the ferromagnetic phase transition is because it's a simple example of self-organization. The human mind is an almost (but not quite!) magical outcome of the interaction of billions of neurons, which is a rather poorly understood example of a phase transition (loss or gain of self-organization)  - neural matter leading to mind rather than watery matter transforming from liquid to solid as it freezes). Even freezing is quite a complicated process so we first looked at an even "easier" example: the ferromagnetic phase transition.

<script type='text/javascript' src='http://demonstrations.wolfram.com/javascript/embed.js' ></script><script type='text/javascript'>var demoObj = new DEMOEMBED(); demoObj.run('The2DIsingModelMonteCarloSimulationUsingTheMetropolisAlgorit', '', '459', '648');</script><div id='DEMO_The2DIsingModelMonteCarloSimulationUsingTheMetropolisAlgorit'><a class='demonstrationHyperlink' href='http://demonstrations.wolfram.com/The2DIsingModelMonteCarloSimulationUsingTheMetropolisAlgorit/' target='_blank'>The 2D Ising Model Monte Carlo Simulation Using the Metropolis Algorithm</a> from the <a class='demonstrationHyperlink' href='http://demonstrations.wolfram.com/' target='_blank'>Wolfram Demonstrations Project</a> by Darya Aleinikava</div><br />

More to follow, including links to videos.