It would have been interesting to see more of the high-speed movement of the
large groups of sheep. From the very short segment in which the mass movement
was shown, it looked to me there were signs of group rotation - although again
we would need much more footage to confirm this. The rule of movement would be
"move to the outside of the flock where there is more room to move faster/avoid
collision where there is room to do so". This results in lines of sheep
movement up the peripheries of the flock that are faster than movement on the
inside, and so an effective backward drift in the centre and an emergent
rotational pattern. There may be "eddies" or other smaller scale rotations
within the flock occurring as well.
This is what happens frequently in bicycle pelotons at a certain threshold of
speed/power output (constituting a phase change) - riders advance up the
periphery while a backward drift down the centre occurs. In pelotons there is
what I call a "forward imperative", a deliberate and conscious attempt by
riders to get or stay near the front of the peloton as there is strategic value
in being positioned near to the front of the peloton.
However, there are also, I believe, physical (self-organized, non-deliberate)
reasons why peloton rotations occur, which are a combination of fatiguing
riders decelerating slightly down the middle and the greater space on the
periphery for fresher riders to pass.
If a similar phenomenon can be seen in flock/school motion, then it strengthens
the argument that the peloton rotation phenomenon is not simply a pattern that
results from riders' deliberate and conscious tactical movements, but is also a
function of purely self-organized processes. A similar form of rotational
patterns occur in penguin huddles, but it would be interesting to confirm the
pattern in other biological aggregates.
Hugh Trenchard
Victoria BC
----- Original Message -----
From: Tom Johnson
To: fr...@redfish. com
Sent: Friday, March 20, 2009 4:10 PM
Subject: [FRIAM] YouTube - Extreme Sheep LED Art
Imagine the creator/artist trying to initially explain to the sheep ranchers
what he was up to and what he wanted them to do. But I love the emergence of
it all, given that the only major rule for the "sheep agents" is "Move away
from the dog. Quickly."
http://www.youtube.com/watch?v=D2FX9rviEhw
-tj
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FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org
