[Phys-L] Chaos at UCSC Was: Re: Rodent Population Model Behavior.

[bernard cleyet <bernard@cleyet.org>]

I can’t believe I missed this.   Much earlier Peter Scott and Robert Shaw performed the drip experiment in the early 80’s.  

Here’s a video on chaos w/ Scott and Shaw's app.     https://www.youtube.com/watch?v=fUsePzlOmxw  

  "This show is now available on YouTube, and may be viewed here. <https://www.youtube.com/watch?v=fUsePzlOmxw> Our experimental setup is displayed in two sections of this video, one starting at approximately 19:15 (showing the Lorenz equations being solved on an analog computer) and the other starting at approximately 29:08 (showing our experiments with a dripping faucet).”  

Scott’s home page:   https://scott.physics.ucsc.edu  



And their paper:   https://www.sciencedirect.com/science/article/abs/pii/0375960185900659  



bc    inherited their Systron-Donner Analog Computer and incorporated it in the Advanced Lab’s  Analog Computer Lab.   W/ Peter’s instruction.  


ps  note the constant head is maintained by an SU carburetor.


> On 2018/Apr/23, at 13:52, Paul Nord <paul.nord@valpo.edu> wrote:
>
> Predator-prey models aren't the only ones that produce these Feigenbaum
> diagrams.  (Bringing this discussion back to physics...)
>
> Dripping faucets do something similar as a function of flow rate:
> http://fy.chalmers.se/~f7xiz/TIF081C/drippingfaucet.pdf <http://fy.chalmers.se/~f7xiz/TIF081C/drippingfaucet.pdf>
>
> We had some students set this up and get frustrated when they adjusted
> things and reported, "It drips at a constant rate and then, sometimes, if
> we bump the table like this [bump] it starts dripping at this other rate."
> The bifurcation in the Feigenbaum diagram is the first indication of the
> onset of chaos.  I think that their apparatus didn't allow for much higher
> flow rates and they never got into the really chaotic regions.
>
> Paul