complex systems phenomena of critical slowing down, and flickering

Hi Felix,

On Feb 20, 2016, at 8:00 AM, Fel Reb <> wrote:

I don't have access to respond to the posthaven blog, so I'm sending it directly to you....

Your questions made me think of meta-stability and Simondon... I don't know if if I'm off in left field but here are my two cents' worth... Gotta say though that f is not just any (differentiable) scalar function… it's a nice way at "inducing" continuity where the underlying may not have it..

Yes, right — in fact distribution theory : representing a function by convolving against approximations to the identity with a kernel that converges to the Dirac delta function is a well known and beautiful way to densely approximate any integrable function — a much vaster set of functions, which includes wildly non-differentiable and even discontinuous functions — by infinitely differentiable functions.

If the second time-derivative is going to zero, one would be approaching a steady state of no change, i.e. no new energy entering or leaving the system.

The second time-derivative of what, prices of Apple stock, immigrant flows through Ellis Island ?  That is only the case when we’re talking about position (potential energy mass * dx).   

If the second time-derivative is positive, why would that induce flickering? If the second derivative is positive at a point, are not you not only providing half the story? Wouldn’t you need to see how the change is changing over time rather than tending? 

Yes exactly, that’s why I speak of second time-derivative f’’: change is f’  and change of change is f’’.

If the potential is locally a quadratic with nonzero second derivative, then it looks like a parabola (in potential space).   The classic dynamic (solution) subject to that sort of potential (differential equation) is harmonic oscillation. 

For the thing to flicker, one would need discontinuities in the system or very tight oscillations to the changing system... tending-positive to infinity, finding another “plateau” of zero (or near zero) and then another tending-negative to infinity and repeat
This flickering effect feels like a cycling of meta-stability where contributing factors within the system impede the system from acquiring a one way or the other... or exit that meta-stable state... the correlation lengths would depend on the energy dynamics of the system, how rough the cycling is, i.e. how much energy is required to get out of the troughs of the meta-stability yet not enough to break away from the cycling and revert to the meta-stable trough. Experimentally, to break the spell one needs to introduce ever larger amounts of energy, heighten the amplitude of the energy dynamics as roughness into the cycling so one overwhelms the threshold boundary and break free from the prevalent dynamic onto another regime. You gotta introduce some rough stuff into the system, i.e. introduce difference or change, to mix it up and break free from the toxic stability....

Does this make sense?

Not clear what you mean by all this.  Are we speaking of the base space, or the state space of configurations, or the space of potential energy (functional on configurations)?

I hope this doesn’t land like a hair in the soup, like they say in Qc French.

hahaha , what’s that in quebecois?

Best, Felix

P.S. I found this reference on my way to somewhere else... thought it might be an interesting comment to the death scenario of the . 

From Nature

Universal resilience patterns in complex networks

Jianxi Gao, Baruch Barzel & Albert-László Barabási

Nature 530, 307–312 (18 February 2016) doi:10.1038/nature16948

Received 13 July 2015 Accepted 14 December 2015 Published online 17 February 2016


Félix Rebolledo


Fone: 51 9110 9920

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RHUTHMOS / Janvier 2016

Worth subscribing to RHUTHMOS!
And worth learning français!
Bien sur!
Xin Wei


Begin forwarded message:

From: Pascal Michon <>
Subject: Dernières publications sur RHUTHMOS / Janvier 2016
Date: January 27, 2016 at 12:51:55 PM MST
To: 'Pascal Michon' <>

Dernières publications sur RHUTHMOS / Janvier 2016
Plateforme internationale et transdisciplinaire de recherche
sur les rythmes dans les sciences, les philosophies et les arts

Janvier 2016

Derniers articles parus
* F. Bisson, Ainsi marche Anna Cruz

En librairie
* M. Salgaro (Hrsg.), M. Vangi (Hrsg.), Mythos Rhythmus.Wissenschaft, Kunst und Literatur um 1900
*J.-L. Evard, Du sensible au sensé

* Hommage à Daniel Buren
* Seeing in the Rain – Chris Gallagher (1981)
* Variations on a Cellophane Wrapper – David Rimmer (1972)
* Savage Messiah – Ken Russell (1972)
* La jetée – Chris Marker (1962)
* Ring-o-graphy – Alexandra Savina (2011)
* Meilleurs Vœux 2016 – Marie Paccou et al.École des Métiers du Cinéma d’Animation
* My Ship – Kurt Weill (1942)
* Les yeux noirs – Django Reinhardt (1947)
* Mélodie au crépuscule – Django Reinhardt (1947)
* Sonnet 130 (1609) – William Shakespeare – Read by Alan Rickman
* Daffodils – William Wordsworth (1804)
* TRANSDISCIPLINAIRES – Call For Papers For the Conference : « Rhythm as Pattern and Variation : Political, Social and Artistic Inflections »

Cet e-mail a été envoyé depuis un ordinateur protégé par Avast.

analog rhythm jam session

Thanks to Adrian Freed for drawing attention to this analog machine + human rhythm jam session “Viviendo la nochebuena en un ricon de sevillano aquí os muestro algo nuevo la máquina de compas y os deseo una feliz navidad a todos, con armonia, sentimiento y compas”

sensorimotor observations of collective movement, Heims Ingalls experiment

Hi Todd,

Thanks.  Can we talk with Pavan, and then Steve Heims?

Yes I’d be very interested in such collective movement experiments.  But then it is urgent that we really prep our own measurement methods and team (Garrett?, ___ ? assisted by Julian).

As you know, I would want to measure correlations not (only) in the brain but across much more of the event.   
It is far more direct (scientifically rigorous) to measure as much of the global aspects of collective movement than to zero in on only one part of the body and in fact a part whose functions are extremely indirectly related to corporal kinetics, and in ways that are quite ill understood . 

That’s why I’ve asked Julian and our students to build out the rhythm kit to use all modalities of sensing intervallic rhythm.

in particular: 

and as an aside:

Can we talk with Pavan, and then with Steve?

Xin Wei

On Dec 4, 2015, at 12:41 PM, Todd Ingalls <> wrote:

could this be tied to rhythm. I think we are both skeptical of brain imaging but could still be interesting. 

todd from my phone

Begin forwarded message:

From: Stephen Helms Tillery <>
Date: December 4, 2015 at 12:26:56 PM MST
To: Todd Ingalls <>
Subject: Back to music and brain

Hey Todd,

Hope you’re good.

I have been working and thinking about a couple of issues a lot lately in group neuroscience .. the two key topics are joint action and entrainment.   Joint action is just multiple actors working together to accomplish some task … like two people carrying a table together, or a couple of soccer players moving the ball down the field.   These are interesting problems because they require the actors to have some sense of what their partners are trying to accomplish and how they are going about that.   Entrainment is an entirely hypothesized process in which two brains come into “synchrony” in order to communicate .. this is thought to be important in language, but obviously is also important in music performance.

Entrainment, however, is pretty loosely defined at the moment … we have an idea for getting at entrainment using musicians.    The notion is to get an ensemble together, a good ensemble … and record simultaneous EEGs from the players as they work a piece.

To some extent this has been done before:   with saxophones (ugh!)   The focus of that paper was on EEG markers of empathy (even more ugh), and the usual expected changes in EEG associated with listening to and motor outputs for music.

What I’d like to do is do real analysis across multiple brains during performance, and see if we can see electrical signs of entrainment as they are working.   In a dream world, as the ensemble locks into “togetherness” … the brains will entrain.   Or vice versa.  

Anyway, to go after this we will need to synch up multiple EEGs, and more importantly, find a good ensemble that might be up for this.    

I thought of AME, and wondered if there would be somebody there interested in devoting a little bit of time and nominal resources to chasing this down.

In any case, have good holidays,


AME research and graduate proseminar: the problem with explaining things in terms of "'parts' of the brain"

Hardcastle and Stewart succinctly point out a fundamental problem at the heart of the methodology of neuroscience (and of cognitive science): the modularity thesis.

Neuroscience did not “discover” modules — loci of functions —  in brains.   Rather “they don’t even have a good way of accessing the appropriate evidence. It is a bias in neuroscience to localize and modularize brain functions.”

The problem with scientistic methodology is that you see what you expect to see.

There’s much more in play: Noah Brender’s work questions the modularity thesis underlying much of technoscience. 
However, another world is possible :)

Xin Wei

Synthesis rhythm: IMU's etc.

Dear Rhythm people: Garrett, Gabby, Julian,

Thanks for being on the demo team !  Now we can get back to steady state  work, like rhythmanalysis 

Can you please check out the IMU’s that we bought last year as an input for our rhythm test platform?
Ask Ozzie or perhaps one of Prof. Turaga’s students who’s used them for permission and see if you can stream them into Max.

I’d like assemble a suite of inputs:
contact mic
air mic
camera (Julian)
IMU (Pavan’s group?)
xOSC gyros (Mike —> Julian)

and record them in parallel
with some movement scenarios to get multiple streams of time data.

Please define some scenarios : e.g.  assembling blocks small to giant size, cutting and washing .  try seated and upper body and locomotive.   Varsha’s done some movement scenarios with Grisha, but in very specialzied contexts.  How about quotidian ?

Let’s try some out on Monday Nov 30?

Xin Wei

cc Pavan

Sha Xin Wei • Professor and Director • School of Arts, Media and Engineering + Synthesis
Herberger Institute for Design and the Arts + Fulton Schools of Engineering • ASU
Fellow: ASU-Santa Fe Consortium for Biosocial Complex Systems
Affiliate Professor: Future of Innovation in Society; Computer Science; English
Founding Director, Topological Media Lab
skype: shaxinwei • mobile: +1-650-815-9962