Order from chaos! And without any external source of energy. I wonder what other physical phenomena emerge this way. Magnetic fields, I bet.
Ordine dal caos, as they say in Italian.
You are getting sleeeeeeepy ...
21–30 of 45 posts
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#22The linked article claims that metronomes start 'pairing up' with their nearest neighbors saying that "strongest forces on a metronome will initially be from its nearest neighbors." But if the forces are spread by the string-suspended table swaying back and forth, I wouldn't expect adjacent metronomes to be significantly more connected than further away ones. Instead, I wonder if we just happen to be better at noticing metronome synchronicity when the metronomes are adjacent. Any pairs that formed several steps away would escape our notice.
Re: You are getting sleeeeeeepy ...
#23Order from chaos! And without any external source of energy. I wonder what other physical phenomena emerge this way. Magnetic fields, I bet.
I think you're right about the magnetic fields. I'm pretty sure the interactions between the metronomes in the video can be modelled as message passing between nodes in a square lattice of variables, with stronger association potentials in the direction of the swing than in the direction perpendicular to it.
As far as I understand it, this is similar to the Ising model of ferro-magnetism [1], where magnetism arises from the interactions of neighbouring atoms.
For more on this kind of stuff, look into graphical models. Coursera has a Stanford course with Daphne Koller on it.
Re: You are getting sleeeeeeepy ...
#24Network protocols with periodic updates will do the same thing; it used to be a problem, so much so that designers would add noise to timing in implementations. Here's a great paper from Sally Floyd and Van Jacobsen on it:
Re: You are getting sleeeeeeepy ...
#25Network protocols with periodic updates will do the same thing; it used to be a problem, so much so that designers would add noise to timing in implementations. Here's a great paper from Sally Floyd and Van Jacobsen on it: http://ee.lbl.gov/papers/sync_94.pdf
That is a fascinating paper. Very cool.
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#26Steven Strogatz has done a lot of work on things like this in the past - including this experiment.
http://www.ted.com/talks/steven_strogatz_on_sync.html
In the simple case of just two metronomes on a single moving plane, the tendency for sync is governed by a non linear differential equation. The math gets rather complicated: http://salt.uaa.alaska.edu/dept/metro.pdf
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#27There is a place in the UK where this happens with spooky regularity with people walking. There is a covered walk way between Waterloo and Waterloo East railway stations. The mob of people enter it unsynchronised and by the time they leave, they are usually all synchronised. I assume this happens in many other places too, I just haven't been every where else to see!!!! I always assumed this was because people can hea…
It was the London Millennium Bridge. Here is a video of the effect in action: https://www.youtube.com/watch?v=gQK21572oSU
Here the problem is attributed to the peoples reaction. The evidence from the metronomes might suggest that it has nothing to do with people.
The fix involves changing the natural frequency of the bridge.
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#28Does this violate the second law of thermodynamics?
Re: You are getting sleeeeeeepy ...
#29Network protocols with periodic updates will do the same thing; it used to be a problem, so much so that designers would add noise to timing in implementations. Here's a great paper from Sally Floyd and Van Jacobsen on it: http://ee.lbl.gov/papers/sync_94.pdf
Here is an example for multicast dns (used in bonjour etc):
http://files.multicastdns.org/draft-cheshire-dnsext-multicas... (page 9)
Re: You are getting sleeeeeeepy ...
#30Does this violate the second law of thermodynamics?
Of course not. Nothing does, that's why it's a law!