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Household vortices, redux

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Nick Thompson

Household vortices, redux

Steve S.,

You and I are the only two participants in that discussion to have presented any empirical evidence. In the spirit of experimental collegiality, would you try my experiment, and report back to me. Fill a basin with water Set it to spinning in a concerted way. Be careful not to impose any more turbulence than you have to. Just help the water to decide which way it is going to spin. Now pull the plug. Watch the water level fall while also watching the organization of the vortex. At some point the “natural” vortex will fall in line with the artificial vortex you have imposed, or vv. When that happens, the rate at which the water line moves down the basin wall will slow dramatically while the vortex spins ferociously. You will think for a moment …. this could go on forever …. and then it doesn’t. If the gradient is the water, above, no water below gradient, AND the gradient dissipation consists of moving the water downward (all suspicious assumptions), then the vortex is certainly slowing the dissipation of that gradient. If, on the other hand, the gradient has something to do with energy, which I don’t understand, obviously¸ then somebody like SG might argue that the very ferocity of the ineffectually spinning vortex is nature’s way of working off the energy gradient, like somebody exercising after a large thanksgiving dinner. The idea would be that a ferociously spinning vortex is a better way to dissipate the potential energy in the water than having the water flow down through the drain. So nature chooses that path. Thus, the same facts (the formation of the vortex slows the draining of the water) could be seen as supporting or countering the theory that “dissipative structures hasten dissipation”. Which means I have to have a better idea of what is being dissipated by a dissipatory structure.

Nicholas S. Thompson

Emeritus Professor of Psychology and Biology

Clark University

http://home.earthlink.net/~nickthompson/naturaldesigns/

http://www.cusf.org

lrudolph

Re: Household vortices, redux

Nick and all,

If the following comment has already been made (and disposed of),
please accept my apologies (the house was full of visitors for a
while and I stopped keeping up with my mail).

One thing that leaps to my eye in the description of the
empirical experiment made by Nick, and suggested to Steve
by Nick, is the opacity of the "pull the plug" part--
both figurative and literal opacity, since (I am assuming)
Nick hasn't got one of those nifty all-glass _
sinks that used to show up in commercials for Drano).
Is it possible that there is some structure of a
vorticial sort located (just) out of sight, within
the water that is exiting the basin (and the drain
pipe through which it is exiting), and that the
energy/organization/whatever of *that* part of the
total water/basin/drain pipe system is closely
(though obscurely) coupled to the visible vortice(s),
in such a way that the observed phenomena follow more
obviously from the facts-including-the-hidden-subsystem
than they seem to be doing from only the facts-not-
including-the-hidden-subsystem? (Peter L., does that
sound even remotely reasonable from your informed
perspective on fluid flow?)

>
>
>
> You and I are the only two participants in that discussion to have presented
> any empirical evidence. In the spirit of experimental collegiality, would
> you try my experiment, and report back to me. Fill a basin with water Set
> it to spinning in a concerted way. Be careful not to impose any more
> turbulence than you have to. Just help the water to decide which way it is
> going to spin. Now pull the plug. Watch the water level fall while also
> watching the organization of the vortex. At some point the "natural" vortex
> will fall in line with the artificial vortex you have imposed, or vv. When
> that happens, the rate at which the water line moves down the basin wall
> will slow dramatically while the vortex spins ferociously. You will think
> for a moment .... this could go on forever .... and then it doesn´t. If the
> gradient is the water, above, no water below gradient, AND the gradient
> dissipation consists of moving the water downward (all suspicious
> assumptions), then the vortex is certainly slowing the dissipation of that
> gradient. If, on the other hand, the gradient has something to do with
> energy, which I don´t understand, obviously¸ then somebody like SG might
> argue that the very ferocity of the ineffectually spinning vortex is
> nature´s way of working off the energy gradient, like somebody exercising
> after a large thanksgiving dinner. The idea would be that a ferociously
> spinning vortex is a better way to dissipate the potential energy in the
> water than having the water flow down through the drain. So nature chooses
> that path. Thus, the same facts (the formation of the vortex slows the
> draining of the water) could be seen as supporting or countering the theory
> that "dissipative structures hasten dissipation". Which means I have to
> have a better idea of what is being dissipated by a dissipatory structure.
>
>
>
>
>
> Nicholas S. Thompson
>
> Emeritus Professor of Psychology and Biology
>
> Clark University
>
> http://home.earthlink.net/~nickthompson/naturaldesigns/
>
> http://www.cusf.org <http://www.cusf.org/>
>
>
>
>
>
>

Nick Thompson

Re: Household vortices, redux

Lee,

Yep! There is that little grid in the mouth of the drain and the little
tornado thingy generally forms on the hole at the center of that grid.
Doesn't explain why the water leaving the drain starts to slow down when the
"natural" vortex forms, by comparison with the circumstance in which I don't
decide for the vortex which way to form. The phenomenon is: if you impart a
turn to the water before you pull the plug, it takes as much as 2 and a half
times longer for the basin to drain.

Anybody else observe that?

Are you asking why does a vortex form at all? Are you assuming that the
drain is "rifled" in some sense and that a vortex wouldn't form without the
rifling. Somehow I doubt that.

N

Pull the plug is, in my case, to remove the thing that ... um ... plugs the
drain. One way to impart a spin on the water is to give the plug --
actually a strainer with a rubber seal on the bottom -- a twist as you pull
it. Not sure that works as well as actually paddling the water around in
the basin to get it turning before you pull the plug.

-----Original Message-----
From: [hidden email] [mailto:[hidden email]] On Behalf
Of [hidden email]
Sent: Saturday, July 02, 2011 12:16 PM
To: The Friday Morning Applied Complexity Coffee Group
Cc: Steve Smith
Subject: Re: [FRIAM] Household vortices, redux

Nick and all,

If the following comment has already been made (and disposed of), please
accept my apologies (the house was full of visitors for a while and I
stopped keeping up with my mail).

One thing that leaps to my eye in the description of the empirical
experiment made by Nick, and suggested to Steve by Nick, is the opacity of
the "pull the plug" part-- both figurative and literal opacity, since (I am
assuming)
Nick hasn't got one of those nifty all-glass _
sinks that used to show up in commercials for Drano).
Is it possible that there is some structure of a vorticial sort located
(just) out of sight, within the water that is exiting the basin (and the
drain pipe through which it is exiting), and that the
energy/organization/whatever of *that* part of the total water/basin/drain
pipe system is closely (though obscurely) coupled to the visible vortice(s),
in such a way that the observed phenomena follow more obviously from the
facts-including-the-hidden-subsystem
than they seem to be doing from only the facts-not-
including-the-hidden-subsystem? (Peter L., does that sound even remotely
reasonable from your informed perspective on fluid flow?)

>
>
>
> You and I are the only two participants in that discussion to have
> presented any empirical evidence. In the spirit of experimental
collegiality, would
> you try my experiment, and report back to me. Fill a basin with water
Set

> it to spinning in a concerted way. Be careful not to impose any more
> turbulence than you have to. Just help the water to decide which way
> it is going to spin. Now pull the plug. Watch the water level fall
> while also watching the organization of the vortex. At some point the
> "natural" vortex will fall in line with the artificial vortex you have
> imposed, or vv. When that happens, the rate at which the water line
> moves down the basin wall will slow dramatically while the vortex
> spins ferociously. You will think for a moment .... this could go on
> forever .... and then it doesn´t. If the gradient is the water,
> above, no water below gradient, AND the gradient dissipation consists
> of moving the water downward (all suspicious assumptions), then the
> vortex is certainly slowing the dissipation of that gradient. If, on
> the other hand, the gradient has something to do with energy, which I
> don´t understand, obviously¸ then somebody like SG might argue that
> the very ferocity of the ineffectually spinning vortex is nature´s way
> of working off the energy gradient, like somebody exercising after a
> large thanksgiving dinner. The idea would be that a ferociously
> spinning vortex is a better way to dissipate the potential energy in
> the water than having the water flow down through the drain. So
> nature chooses that path. Thus, the same facts (the formation of the

vortex slows the draining of the water) could be seen as supporting or
countering the theory
> that "dissipative structures hasten dissipation". Which means I have to
> have a better idea of what is being dissipated by a dissipatory structure.

>
>
>
>
>
> Nicholas S. Thompson
>
> Emeritus Professor of Psychology and Biology
>
> Clark University
>
> http://home.earthlink.net/~nickthompson/naturaldesigns/
>
> http://www.cusf.org <http://www.cusf.org/>
>
>
>
>
>
>

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Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives,
unsubscribe, maps at http://www.friam.org

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

Stephen Guerin

Re: Household vortices, redux

In reply to this post by Nick Thompson

Nick,

Apologies for a slow response - I'm on summer break with the family and it's a good question for which I don't have a quick answer. Your question reflects similar "surprises" I've had playing with water vortices when trying to use them to illustrate the general idea of structure formation in far-from-equilibrium systems.

My experimentation is at the level of an average 7th-grader, so don't expect much...

My first surprise was a couple years back with my kids at Explora Science museum playing with one of their whirlpool exhibits. video: http://www.youtube.com/watch?v=-yb7PTMtmN8.

As you can see in the video, there is a small hole in the bottom of a large cylinder of water. At the top is a return hose injecting water at apparently constant flow at the top of the cylinder. I assume the hose was providing water at near constant flow and not a variable return flow because when I plugged the the bottom of the cylinder, the cylinder filled up and overflowed. The hose is aligned with the edge of the cylinder so the incoming water supplies some angular momentum. It is possible to rotate the hose so it doesn't inject water along the side and instead flows to the middle. When the hose is pointed toward the middle, the whirlpool disappears. My expectation in the absence of the whirlpool was the level of water in the cylinder would increase. My surprise was that the water level did not noticeably change. Roughly a similar result to your basin experiment.

My second surprise about 8 years ago was when I first played with a tornado-tube kids toy based on claims by Eric Schneider and James Kay that the presence of the vortex changed the rate of exchange between air and water from 6 minutes to 11 seconds. I bought of few of the tornado tubes and definitely saw the same results within an order of magnitude. This experiment shows dramatically increased flow in the presence of the ordered channel of the vortex.

However, I was surprised that I had to inject considerable angular momentum to get the whirlpool started by spinning the bottles. I was hoping the structure would simply emerge from the initial conditions or at least some random shaking figuring I might need to put some noise in there to get micro rotations going and let positive feedback amplify them up to a vortex. Alas, not the case.

I think the critical difference between the tornado-in-a-bottle and the two experiments of your basin and the explora exhibit, is that the tornado-in-a-bottle has a near vacuum of air on top of the water. The vortex assists in creating a channel for the air at the bottom to fill the vacuum at the top. I'm wondering if a hurricane or tornado is more like the tornado-in-a-tube or more like your basin experiment. I suspect it's the former.

You can approximate a tornado in a tube as a kitchen experiment by inverting a plastic water bottle and draining it into your sink. Compare the drainage rate without vortex formation and with vortex formation by spinning the bottle. For best results use a larger 1-liter water bottle. You can play with the size of the opening by keeping the cap on and drilling different size holes. Also, compare this to a bottle that has a hole drilled at the top that you can open and close with your finger - what some folks on the list might refer to as a "carb" :-). It's amazing how fast and laminar the water flow is when you open the carb.

To make the system more of closed system, you can use two water bottles sloppily closed with duct tape or purchase one of these guys: http://www.amazon.com/Tornado-Tube-Tubes/dp/tech-data/B0006Z8YBQ. If you prefer you can construct one at home with two watercaps and a teflon pan:

http://www.sciencetoymaker.org/vortex/index.html

- Stephen

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lrudolph

Re: Household vortices, redux

In reply to this post by Nick Thompson

> Are you asking why does a vortex form at all?

No.

> Are you assuming that the
> drain is "rifled" in some sense and that a vortex wouldn't form without the
> rifling.

No, that hadn't occurred to me, and I don't think
(having done my share of household-level plumbing)
that drains are rifled in any sense.

Like Isaac Newton (not Abraham Lincoln's secretary
of agriculture, who should be better known than he
is for having written "there is no logic so irresistible
as the logic of statistics; some other guy of the same
name), I am not feigning (or framing) hypotheses on
these matters, at the moment anyway. I was mainly
pointing out that your reported observation, about
the (great) slowness to drain of a vortex-infested
sinkful of water, *is* an observation *about a sink
full of water*, not (just) about the visible part
of the water, or even (just) about the water and the
visible surfaces of the sink. At least part of the
water that is already out of sight (at any particular
time during the process of draining the sink) is most
definitely mechanically involved with whatever is
happening, as is at least part of the sink (the top
bits of the drainpipe) that is out of sight during
the whole experiment, because that water (rather,
the outer layers thereof) is touching that part
of the sink.

Like the man said, no system is an island, entire
of itself; every system is a subsystem of the
Universe, a part of the main ... And therefore
never send to know for whom entropy increases;
it increases for thee.

--Not that I'm framing any hypotheses about
order or disorder, mind you.

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org