
Scientists Discover Exotic New Patterns of Synchronization - headalgorithm
https://www.quantamagazine.org/physicists-discover-exotic-patterns-of-synchronization-20190404/
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pmayrgundter
This bit:

"The scientists mapped the different synchronized clusters that can form in a
network of oscillators to that network’s symmetries. In this context,
symmetries refer to the ways a network’s oscillators can be swapped without
changing the network, just as a square can be rotated 90 degrees or reflected
horizontally, vertically or diagonally without changing its appearance." ...
"The synchronized part is one big synchronized cluster, and the desynchronized
part is a bunch of single clusters"

Sounds like Chladni/Faraday patterns to me:

[https://en.wikipedia.org/wiki/Ernst_Chladni#Chladni_figures](https://en.wikipedia.org/wiki/Ernst_Chladni#Chladni_figures)

The symmetry group might be the network of anti-nodes, which vibrate in common
with the shared energy reflecting through the medium. The nodes seem less
likely, as that's where the energy waves cancel out, thus providing less kick
against the local oscillators to overcome their independent motion.

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nitrogen
I wonder what those would look like if you had multiple oscillators that could
move around the plate along the gradient of lowest resistance to their
oscillation, sort of like the opposite of the flour. I'm also curious if
there's a way of extending (or reducing?) this bulk material resonance to
graphs of incompletely interconnected nodes.

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aerialfrog
In a Mythbusters episode they set up coupled metronomes. One of the metronomes
didnt sync up and the host was annoyed. He may have unwittingly discovered the
chimera state
[https://www.youtube.com/watch?v=e-c6S6SdkPo](https://www.youtube.com/watch?v=e-c6S6SdkPo)

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AgentME
>Roukes, who is a professor of physics, applied physics and biological
engineering at Caltech, is most interested in what the ring of NEMs suggests
about huge networks like the brain. “This is very, very primordial compared to
the complexity of the brain,” he said. “If we already see this explosion in
complexity [in a network of 8 NEM oscillators], then it seems feasible to me
that a network of 200 billion nodes and 2,000 trillion [connections] would
have enough complexity to sustain consciousness.”

I wonder if there's a good way to integrate something about oscillation into
neural networks.

~~~
trevyn
You may be interested in György Buzsáki’s “Rhythms of the Brain”:

[https://www.amazon.com/Rhythms-Brain-Gyorgy-
Buzsaki/dp/01998...](https://www.amazon.com/Rhythms-Brain-Gyorgy-
Buzsaki/dp/0199828237)

“...self-emerged oscillatory timing is the brain's fundamental organizer of
neuronal information. The small-world-like connectivity of the cerebral cortex
allows for global computation on multiple spatial and temporal scales. The
perpetual interactions among the multiple network oscillators keep cortical
systems in a highly sensitive "metastable" state and provide energy-efficient
synchronizing mechanisms via weak links.”

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damip
Here is also a Nature paper about using synchronization phenomena in coupled
solid state spintronic nano-oscillators to achieve vowel recognition:

[https://www.nature.com/articles/s41586-018-0632-y](https://www.nature.com/articles/s41586-018-0632-y)

Arxiv PDF:
[https://arxiv.org/ftp/arxiv/papers/1711/1711.02704.pdf](https://arxiv.org/ftp/arxiv/papers/1711/1711.02704.pdf)

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trevyn
Sci-hub doesn’t seem to have it, but Google shows the full paper mentions
something about simulation. It looks like it’s only 8 oscillators and they
actually built a physical implementation — why couldn’t this all have been
done in simulation?

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sdx23
[http://scholar.google.com](http://scholar.google.com) has the full-text pdf
if you put in the title.

~~~
trevyn
Ah, thanks! PDF link:

[http://nano.caltech.edu/publications/papers/Matheny-2019-Sci...](http://nano.caltech.edu/publications/papers/Matheny-2019-Science.pdf)

Looks like they did simulate it, and the experimental results differed from
the simulation due to number of harmonic terms used: “To obtain quantitative
agreement between the phase model (Eq. 3) and the experiment, additional terms
in the harmonics of the magnitudes would need to be included in the phase
model.” Which I suppose implies that very weak, distant harmonics might play
an important role in these patterns.

Also an earlier paper from the same group that discusses infeasibility of
other approaches:
[https://authors.library.caltech.edu/81293/1/acs.nanolett.7b0...](https://authors.library.caltech.edu/81293/1/acs.nanolett.7b02026.pdf)

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carapace
There are awesome videos of ranks of metronomes syncing up.

I wonder how synchronization "interacts" with Relativistic non-simultaneity?

~~~
qubex
Relativity (even of the ’easy’ Special variety) can have very peculiar effects
on physical systems.... I remember trying to solve for a relativistic
pendulum, and it was a seriously intricate situation.

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pontifier
Several years ago at DEFCON the badges had LEDs but also had IR LEDs, as well
as an IR sensor. I wanted to write a program to flash the LEDs, but wanted
groups of the badges to synchronise their flashes... It was harder than I
thought, and I never did come up with an appropriate solution, though I think
about it from time to time.

~~~
ignoramous
May be you hadn't come across
[https://ncase.me/fireflies](https://ncase.me/fireflies)

If you look at the news.yc discussion
[https://news.ycombinator.com/item?id=14452832](https://news.ycombinator.com/item?id=14452832)
at least one user had managed to sync LEDs using a similar model.

~~~
pontifier
Well gee... That probably would have worked... maybe I'll try it again next
time I get the chance.

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dreix
I read dentists. ..

