[FRIAM] Swirlies redux

Sat Aug 5 11:09:47 EDT 2023

There were 10 or so intermediate prompts to drive chatGPT to that lab
report.

On Sat, Aug 5, 2023, 8:52 AM Stephen Guerin <stephen.guerin at simtable.com>
wrote:

> chatGPT, you are a graduate student at c the Santa Fe Institute's complex
> systems summer school, write a lab report on your experiences with the
> tornado in a tube.
>
>
> **Student Lab Report**
>
> **Title:** Insights into Fluid Dynamics and Symmetry Breaking via 'Tornado
> in a Tube'
>
> **Objective:** This lab aimed to explore the critical principles of fluid
> dynamics, including the principle of least action, surface tension, broken
> symmetry, and their impacts on fluid behavior, using the 'tornado in a
> tube' experiment. We introduced variations in the system's orientation,
> structural changes, and the application of external forces to further
> understand these principles.
>
> **Method:** Our setup included two 2-liter clear plastic bottles, water, a
> tube connector, and glitter for fluid visualization. We followed the
> procedure outlined in the lab exercise, with additional testing for
> different system orientations, external force applications, and structural
> modifications.
>
> **Findings:**
>
> 1. **Role of Surface Tension in Vertical Setup:** With the bottles
> vertically aligned, surface tension at the bottleneck significantly slowed
> the drainage process. This resulted in a droplet-like flow and a drainage
> time of 8 minutes and 12 seconds.
>
> 2. **Influence of External Forces:** By applying an external force to the
> system—squeezing the top bottle in pulses—we managed to overcome the
> surface tension resistance. This modified approach expedited the drainage
> process to a time of 1 minute and 47 seconds.
>
> 3. **Impact of System Orientation:** We then experimented with tilting the
> bottles to different angles. A tilt of approximately 42 degrees provided
> the quickest drainage time—2 minutes and 32 seconds. The tilt balanced the
> inflow of air and the outflow of water, thereby managing the effects of
> surface tension effectively.
>
> 4. **Vortex Formation, Symmetry Breaking and the Principle of Least
> Action:** In the next step, we swirled the top bottle to form a vortex,
> leading to a broken symmetry in angular momentum. This energy-efficient
> pathway embodied the principle of least action, allowing the water to
> overcome the surface tension barrier and to drain in an impressive 18
> seconds. This broken symmetry enabled the efficient dissipation of the
> gradient between the bottles.
>
> 5. **Effects of Structural Changes:** Our final test involved an
> open-ended tube setup. Here, we observed noticeable changes in fluid
> behavior. The vortex's efficiency in gradient dissipation decreased due to
> interference from the ambient pressure, indicating the crucial role
> structural features play in fluid dynamics.
>
> **Conclusion:** The 'tornado in a tube' experiment, complemented by our
> additional tests, provided a comprehensive understanding of fluid dynamics
> principles. The observed differences in drainage times highlighted the
> significant impact of system orientation, the principle of least action,
> surface tension, and broken symmetry on fluid dynamics. These findings
> offer deeper insights into fluid behavior and are applicable to a range of
> real-world phenomena, from weather systems to biological processes.
>
> On Fri, Aug 4, 2023, 8:05 PM Nicholas Thompson <thompnickson2 at gmail.com>
> wrote:
>
>> Ok, folks. I apologize to those of you who are fed up with my kitchen
>> physics, but there has been a bit of a development in that saga that I want
>> to share with those few of you who aren’t.   Years ago, I came home for
>> the summer with my ears ringing with the notion that structures are formed
>> to dissipate gradients.  Please set aside any teleological implications
>> of this statement and ask the question in its most neutral form:  Do the
>> structures that sometimes form as a gradient is dissipated dissipate it
>> more quickly once the structure has been formed.   Or, as I came to
>> interpret it, does facilitating the formation of such a structure speed the
>> dissipation of the gradient.
>>
>> I was the family dishwasher at the time.  I deplore washing dishes, but
>> I love messing around with warm soapy water, and so I started to experiment
>> with starting the vortex that forms *after* you pull the plug out of the
>> sink *before* I pulled the plug.  Quickly, it became apparent that
>> facilitating the vortex formation in that way GREATLY SLOWED the emptying
>> of the sink.  Triumphally, I wrote Steve on Friam only to be greeted by
>> a torrent of scatological raillery, so intense and so persistent from the
>> fluid dynamicists on the list that I never heard from Steve. The burden of
>> this raillery I have distilled into Roberts Rule of Order:  DEFROCKED
>> ENGLISH MAJORS SHOULD NOT BE ALLOWED TO TALK about fluid dynamics.
>>
>> More than a decade later, I am back in Massachusetts, washing dishes at
>> the same sink, and the question occurred to me again. I raised it finally
>> with Steve, and he generously sent me the little two-bottle toy, where you
>> flip it over and the water drains from one bottle to the other.  As it
>> drains, it forms a vortex in the draining bottle, and the occurrence of the
>> vortex greatly *increases* the speed of the draining.  Finally, if one
>> facilitates the formation of the vortex by rotating the bottle a bit, the
>> bottle drains even more quickly.  Thus, the result is entirely
>> different, especially if one substitutes two large pop bottles for the ones
>> included in the kit.
>>
>> At the risk of bringing another round of raillery down on my head, I
>> opine that the difference has something to do with the fact that two bottle
>> situation is more of a closed system than the sink situation.  The test
>> would be to saw the bottom off both bottles and demonstrate that
>> vortex-formation now slows drainage.
>>
>> It will be a while, though, before I can get two extra bottles to destroy.
>>
>>
>> Does anybody care to make a prediction and offer an explanation why the
>> results should be different in the two cases?
>>
>> Nick
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>
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