The Surprising Synchronicity of Unanimous Decisions

[Trunnions]

And now for something completely different...

Don't miss the latest issue of the "New Journal of Physics".

Hungarian scientists are studying how flocks of foraging birds make the decision to land. Perhaps you've noticed how huge flocks of starlings will move as one, twisting and turning without an apparent leader, and deciding to land as a unit.

"Collective decision making in cohesive flocks: New Journal of Physics"
http://iopscience.iop.org/1367-2630/12/9/093019/

You see the same behaviour in shoals of fish, packs of hunting ants, swarming bees, and in many other social creatures; which is obviously why I'm posting this here.

Cycling in a peloton is much the same as flocking; with a loosely defined, often changing, leader. How often have you noticed that you go through the same mental behavioural adjustments that shoaling fish and flocking birds must experience?

It happens constantly; you change speed, as the group does: Not as you might wish. You are forced to alter direction slightly: When you don't really want to, and so on.

Blimey, the peloton even has a synchronous pee, and feeding time.

The scientific model uses a simple self-propelled particle (SPP) system, each particle representing a bird.

They find that without a decision making leader, the collective decision to land is greatly influenced by disturbances the individual birds are subject to, such as the birds' flying position within the flock.

Now doesn't that describe exactly what we experience in the peloton too? Try picking your own line around a 90 degree left hand turn, whilst in the peloton, and you'll come a cropper. The "flock" picks your line for you.

Comments from simple self-propelled particles welcome...

 

[Guttercat]

Blimey, the peloton even has a synchronous pee, and feeding time.

So do chicks in a bar, which I never understood.

 

[the student]

So do chicks in a bar, which I never understood.

one of most the mysterious types of behaviour women show

But the entire peloton does get influenced by the road in front of them...
if the front starts braking for a narrow passage the rest behind them wont be able to go just as fast... but the same goes for large groups at festvals etc... if a small group starts running in a certain direction there is a large change the whole group will do so... simply because they cant go another way and they will get trampled if they dont do so...

The group itself doesnt make a descision because a group cant think... the individuals on the outside of the group influence what the rest of the group will do.

If the outside fish of a shole see a predator they will react, the reaction of the group is the accumulation of the reactions, influenced by other fish who see the one fish reaction... they do not see whats happening themselves...

but still its an interesting investigation

 

[Trunnions]

the student said:
Q/
The group itself doesnt make a descision because a group cant think... the individuals on the outside of the group influence what the rest of the group will do.
/Q

This appears to have been the obvious motivating factor for the study. The unanswered questions being, "how", and "what precise factors influence the group decision?".

Q/
If the outside fish of a shole see a predator they will react, the reaction of the group is the accumulation of the reactions, influenced by other fish who see the one fish reaction... they do not see whats happening themselves...
/Q

Have a look at the full study and you'll see it's much more involved than a mere "accumulation of the reactions". What was particularly surprising was the +rapidity+ of spread of the "decision" through the SPPs.

"Collective decision making in cohesive flocks: New Journal of Physics"
http://iopscience.iop.org/1367-2630/12/9/093019/pdf/1367-2630_12_9_093019.pdf

And remember, that model is very simple, based on just one boundary, ie. "landing"; so imagine how complicated it gets when starlings enjoy an en-masse aerial display!

Then try to transpose that to the cycling peloton, which of course only functions in two dimensions, not the three axes of flight.

I don't know about you, but keeping place in a 2D peloton taxes my senses severely, I can't conceive of being able to do it in 3D.

In fact, what starlings achieve in their aerial peloton is vastly superior to any aeroplane flying display I've ever seen.

The Red Arrows Team would have to be thousands, not just five planes; keep tighter formation, in multiple layers, and never prang.

Starlings win, hands down!

Perhaps, experienced peloton riders can contribute to the Hungarian study, because riders have learned, to a much inferior degree, what the birds do naturally. So cyclists are more conscious of the parameters than birds will be.

It's more than monitoring and maintaining personal space in a bunch. Think, for example, of auditory cues such as a brief screech of brakes, and how the novice reacts compared with an experienced rider.

 

[Trunnions]

Interesting new Italian research shows how Starling aerial pelotons rely on three basic rules common to cycling.

"How Starling flocks create their aerobatic displays"
http://news.bbc.co.uk/earth/hi/earth_news/newsid_9175000/9175793.stm

But if you want to join them you'll need a reaction time of 100 milliseconds.

What's your visual reaction time in the bunch; 1,000-3,000 milliseconds?

 

[Polyarmour]

Interesting new Italian research shows how Starling aerial pelotons rely on three basic rules common to cycling.

"How Starling flocks create their aerobatic displays"
http://news.bbc.co.uk/earth/hi/earth_news/newsid_9175000/9175793.stm

But if you want to join them you'll need a reaction time of 100 milliseconds.

What's your visual reaction time in the bunch; 1,000-3,000 milliseconds?

1000-3000 milliseconds is 1 to 3 seconds.

That would definitely be a delayed reaction.

 

[Trunnions]

@Polyarmour:
Yes 1-3 seconds, test yourself and you'll see that's about average, not delayed.

Remember, what we are testing, is not a reaction to a starter's gun, but a +precisely modulated response+ to multiple visual cues.