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Wednesday, January 4, 2017

That Magical Number 7....

I studied cognitive psychology back in the day when George Miller’s piece "The Magical Number Seven, Plus or Minus Two” was still a key, seminal paper in memory and cognition. And so I was slightly amused to see the number 7 arise once again today in the completely unrelated context of "starling murmuration," where individual birds must optimize their behavior within "a dynamic system in which the parts combine to make a whole with emergent properties":
"Just incredibly cool," as Barbara King writes.
I think George Miller would smile...

…and, sidenote, lest anyone dare forget, 7 was also Mickey Mantle’s jersey number:

I'm assuming most readers are somewhat familiar with bird murmurations since there have been so many videos posted in the last few years, but if somehow you've missed them you can find plenty at YouTube HERE, including this one set to music:

By the way, there really is math here, under the biological heading of "swarm behavior." A small bit from Wikipedia:
"Swarm algorithms follow a Lagrangian approach or an Eulerian approach. The Eulerian approach views the swarm as a field, working with the density of the swarm and deriving mean field properties. It is a hydrodynamic approach, and can be useful for modelling the overall dynamics of large swarms. However, most models work with the Lagrangian approach, which is an agent-based model following the individual agents (points or particles) that make up the swarm. Individual particle models can follow information on heading and spacing that is lost in the Eulerian approach."

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