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: [email protected] [mailto:[email protected]] On Behalf Of [email protected] 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/> > > > > > > ============================================================ 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 ============================================================ 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
