“My mind wanders” – – Sheriff Ed Tom Bell, No Country for Old Men
I was driving northbound on 101 on Saturday morning, taking one of my children to an SAT test, when I noticed a flock of birds in the air. There were dozens of them, and they all moved in that graceful fashion that you’ll often see in a flock.
I started to think about how similar this behavior was to the individual participants in the markets. The term for this behavior – murmuration – has a surprising amount of information behind it. I found this quote interesting:
The researchers derived a mathematical description of how a turn moves through the flock. They assumed each bird had a property called spin, similar to the spins of elementary particles in physics. By matching one another’s spin, the birds conserved the total spin of the flock. As a result of that conservation, the equations showed that the information telling birds to change direction travels through the flock at a constant speed—exactly as the researchers observed. It’s this constant speed that enables everyone to turn in near-unison, the team reports online today in Nature Physics.
Here’s another interesting tidbit:
The propagation of this maneuver wave, as he called it, begins relatively slowly but can reach speeds three times faster than would be possible if birds were simply reacting to their immediate neighbors. Potts called this ability among flocking birds the chorus line hypothesis. That is, he said, birds are like dancers who see an approaching leg kick when it’s still down the line, and anticipate what to do. According to Wayne Potts, a zoologist who published in the journal Nature in 1984, birds in flocks are able to change direction quickly not just because they are following a leader, or their neighbors, but because they see a movement far down the line and anticipate what to do next. Potts called this the chorus-line hypothesis for bird movement.
And just one more:
Refining Radakov’s theory had to wait until the 1980s, when computer programmers began to create models that show how simulated animal groups can respond to the movements of individuals within them. It turns out that only three simple rules suffice to form tightly cohesive groups. Each animal needs to avoid colliding with its immediate neighbors, to be generally attracted to others of its kind, and to move in the same direction as the rest of the group. Plug those three characteristics into a computer model, and you can create “virtual swarms” of any sorts of creatures you like. They change density, alter their shape, and turn on a dime—just as real-world birds do.
It makes me think charting is perhaps far too two-dimensional. I’ll have to think about this!
