Re: [FRIAM] symmetry breaking video
Nick, Take a look at this video http://www.dhingana.com/video/rodin-coil-vortex-in-water/related-_-d71vJQ89M /1 You can see the water level rising as it is thrown to the side and nearly empty toward the centre. The experiment is also happily modest . Vladimyr From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Nicholas Thompson Sent: July-02-11 10:47 PM To: 'The Friday Morning Applied Complexity Coffee Group' Subject: Re: [FRIAM] symmetry breaking Vladimyr, I love it! I am going on a trip, so unless my host is particularly forgiving, fear that I wont be able to try it at his house, but I sure will when I get back. Contrary to Lee, I don't think, however, that confined water has anything to do with it. Plumbing systems have pressure release pipes that vent gas upward as water rushes downward from the sink. But the straw is a nice test of that proposition. Nick From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Vladimyr Burachynsky Sent: Saturday, July 02, 2011 8:54 PM To: 'The Friday Morning Applied Complexity Coffee Group' Subject: Re: [FRIAM] symmetry breaking Hello All, Years ago I ran some funky little tests spinning liquid epoxy on a platter to attempt perfect parabolas. The equations required angular velocity and viscosity to get the correct equation for curvature. If your sink is analogous then the swirling motion should leave the water near the drain at the lowest point with the lowest pressure. The surface near or at the margins should contain more water. The surface area has also changed. So now you should get a long soda straw and stick into the drain and see if there is a relationship to the air in the system trying to escape the drain . A suggestion, set up a free Sky Drive account and dump some video with notes and we can all have a look without the Viagra adverts. Sprinkle some floaters ( rubber duckies) and see how they travel perhaps. Vladimyr Ivan Burachynsky PhD vbur...@shaw.ca 120-1053 Beaverhill Blvd. Winnipeg,Manitoba, R2J3R2 Canada (204) 2548321 Land From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Roger Critchlow Sent: June-30-11 1:32 PM To: The Friday Morning Applied Complexity Coffee Group Subject: Re: [FRIAM] symmetry breaking So here's a vortex game for you all. There is a fleet of sail boats racing from Newport, Rhode Island across the Atlantic to the mouth of the English Channel. If you go to http://www.nyyc.org/transatlantic/ and click on [Tracker] you'll get a map of the North Atlantic with the positions and tracks of the boats marked. The red line is the great circle from south of Nantucket to the finish, the shortest path. Up on the control bar there's a button which will turn on a wind direction/intensity overlay so you can see the low pressure SE of Greenland with an eastern arm that stretches almost to the Azores; the high pressures centered west of Brest, SW of Greenland, way south of the Great Banks; and the head wind that the fleet is beating into. There's a slider under the weather button which allows you to step the wind overlay forward in time to the predicted winds at 3hour intervals in the future. Find the fastest path given where the wind is, how well you can drive the boat, and where you expect you and the wind will be on the next watch. The wind arrows the map shows are from the freely available NOAA GRIB models, but most of those boats are getting the best weather predictions that money can buy. Human ingenuity vs fluid dynamics, the state of the art, no doubt getting very wet at the moment. -- rec -- On Thu, Jun 30, 2011 at 11:13 AM, Roger Critchlow r...@elf.org wrote: There are several papers from Ken Dill and students that deal with these approaches. And i don't think you missed them, they turned up after a discussion on Maximum Entropy Production principles. -- rec -- On Thu, Jun 30, 2011 at 11:00 AM, Steve Smith sasm...@swcp.com wrote: On 6/30/11 8:02 AM, Nicholas Thompson wrote: Thanks, Eric, for taking the question seriously. I will study your answer with care. Ask a simple question, and waddya get? Another day older and deeper in (conceptual) debt! Eric says: All these flow problems that we talk about are not described by equilibrium ensembles; they are ensembles of processes. Of course, everybody says that, but apparently most of the time people don't act as if saying that should then carry meaning for what they think afterward. (Like other mantras, its function appears to be to suppress pre-frontal cortex activity.) What a great insight! I wonder how much of our blather here on this list is in fact crafted or selected for it's ability to suppress pre-frontal cortex activity? Wow! While we *think* we are promoting pre-frontal activity, we may very well be supressing it! I wonder
Re: [FRIAM] symmetry breaking
Hello All, Years ago I ran some funky little tests spinning liquid epoxy on a platter to attempt perfect parabolas. The equations required angular velocity and viscosity to get the correct equation for curvature. If your sink is analogous then the swirling motion should leave the water near the drain at the lowest point with the lowest pressure. The surface near or at the margins should contain more water. The surface area has also changed. So now you should get a long soda straw and stick into the drain and see if there is a relationship to the air in the system trying to escape the drain . A suggestion, set up a free Sky Drive account and dump some video with notes and we can all have a look without the Viagra adverts. Sprinkle some floaters ( rubber duckies) and see how they travel perhaps. Vladimyr Ivan Burachynsky PhD mailto:vbur...@shaw.ca vbur...@shaw.ca 120-1053 Beaverhill Blvd. Winnipeg,Manitoba, R2J3R2 Canada (204) 2548321 Land From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Roger Critchlow Sent: June-30-11 1:32 PM To: The Friday Morning Applied Complexity Coffee Group Subject: Re: [FRIAM] symmetry breaking So here's a vortex game for you all. There is a fleet of sail boats racing from Newport, Rhode Island across the Atlantic to the mouth of the English Channel. If you go to http://www.nyyc.org/transatlantic/ and click on [Tracker] you'll get a map of the North Atlantic with the positions and tracks of the boats marked. The red line is the great circle from south of Nantucket to the finish, the shortest path. Up on the control bar there's a button which will turn on a wind direction/intensity overlay so you can see the low pressure SE of Greenland with an eastern arm that stretches almost to the Azores; the high pressures centered west of Brest, SW of Greenland, way south of the Great Banks; and the head wind that the fleet is beating into. There's a slider under the weather button which allows you to step the wind overlay forward in time to the predicted winds at 3hour intervals in the future. Find the fastest path given where the wind is, how well you can drive the boat, and where you expect you and the wind will be on the next watch. The wind arrows the map shows are from the freely available NOAA GRIB models, but most of those boats are getting the best weather predictions that money can buy. Human ingenuity vs fluid dynamics, the state of the art, no doubt getting very wet at the moment. -- rec -- On Thu, Jun 30, 2011 at 11:13 AM, Roger Critchlow r...@elf.org wrote: There are several papers from Ken Dill and students that deal with these approaches. And i don't think you missed them, they turned up after a discussion on Maximum Entropy Production principles. -- rec -- On Thu, Jun 30, 2011 at 11:00 AM, Steve Smith sasm...@swcp.com wrote: On 6/30/11 8:02 AM, Nicholas Thompson wrote: Thanks, Eric, for taking the question seriously. I will study your answer with care. Ask a simple question, and waddya get? Another day older and deeper in (conceptual) debt! Eric says: All these flow problems that we talk about are not described by equilibrium ensembles; they are ensembles of processes. Of course, everybody says that, but apparently most of the time people don't act as if saying that should then carry meaning for what they think afterward. (Like other mantras, its function appears to be to suppress pre-frontal cortex activity.) What a great insight! I wonder how much of our blather here on this list is in fact crafted or selected for it's ability to suppress pre-frontal cortex activity? Wow! While we *think* we are promoting pre-frontal activity, we may very well be supressing it! I wonder if there is a simple heuristic for recognizing mantras in clear text? Going recursive here, I wonder about the brain-state/chemistry that might be involved in our (my!) propensity for (near) idle speculation about things I know just enough about to be dangerous. There seems to be something very soothing about this kind of speculation... hmmm? As for the rest of your (Eric) response! What a lot to unpack... I mostly get process vs equilibrium ensembles, spaces of histories and and some of the entropy talk, but am lost entirely on the topic of competing definitions of diffusion and it's precise relevance to this conversation... I'll give it my best shot though... dig a little deeper. I believe This is the Dill paper http://www.google.com/url?sa=tsource=webcd=1ved=0CBYQFjAAurl=http%3A%2F %2Fwww.dillgroup.ucsf.edu%2Fdl_papers%2FJCP2008Stock.pdfrct=jq=ken%20dill% 20caliberei=_KIMTqSdNZT2swOvkLCQDgusg=AFQjCNF1QwcT3WourQaoLPT8EvAX1tfG4ws ig2=0YsVN6J1NJanyAIYt3rszQcad=rja you refer to? I missed it the first time it was passed around I think. Or with your just-out re-attribution to RC, rather than NT And here is a lecture by Dill http://mitworld.mit.edu/video
Re: [FRIAM] symmetry breaking
Vladimyr, I love it! I am going on a trip, so unless my host is particularly forgiving, fear that I wont be able to try it at his house, but I sure will when I get back. Contrary to Lee, I don't think, however, that confined water has anything to do with it. Plumbing systems have pressure release pipes that vent gas upward as water rushes downward from the sink. But the straw is a nice test of that proposition. Nick From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Vladimyr Burachynsky Sent: Saturday, July 02, 2011 8:54 PM To: 'The Friday Morning Applied Complexity Coffee Group' Subject: Re: [FRIAM] symmetry breaking Hello All, Years ago I ran some funky little tests spinning liquid epoxy on a platter to attempt perfect parabolas. The equations required angular velocity and viscosity to get the correct equation for curvature. If your sink is analogous then the swirling motion should leave the water near the drain at the lowest point with the lowest pressure. The surface near or at the margins should contain more water. The surface area has also changed. So now you should get a long soda straw and stick into the drain and see if there is a relationship to the air in the system trying to escape the drain . A suggestion, set up a free Sky Drive account and dump some video with notes and we can all have a look without the Viagra adverts. Sprinkle some floaters ( rubber duckies) and see how they travel perhaps. Vladimyr Ivan Burachynsky PhD vbur...@shaw.ca 120-1053 Beaverhill Blvd. Winnipeg,Manitoba, R2J3R2 Canada (204) 2548321 Land From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Roger Critchlow Sent: June-30-11 1:32 PM To: The Friday Morning Applied Complexity Coffee Group Subject: Re: [FRIAM] symmetry breaking So here's a vortex game for you all. There is a fleet of sail boats racing from Newport, Rhode Island across the Atlantic to the mouth of the English Channel. If you go to http://www.nyyc.org/transatlantic/ and click on [Tracker] you'll get a map of the North Atlantic with the positions and tracks of the boats marked. The red line is the great circle from south of Nantucket to the finish, the shortest path. Up on the control bar there's a button which will turn on a wind direction/intensity overlay so you can see the low pressure SE of Greenland with an eastern arm that stretches almost to the Azores; the high pressures centered west of Brest, SW of Greenland, way south of the Great Banks; and the head wind that the fleet is beating into. There's a slider under the weather button which allows you to step the wind overlay forward in time to the predicted winds at 3hour intervals in the future. Find the fastest path given where the wind is, how well you can drive the boat, and where you expect you and the wind will be on the next watch. The wind arrows the map shows are from the freely available NOAA GRIB models, but most of those boats are getting the best weather predictions that money can buy. Human ingenuity vs fluid dynamics, the state of the art, no doubt getting very wet at the moment. -- rec -- On Thu, Jun 30, 2011 at 11:13 AM, Roger Critchlow r...@elf.org wrote: There are several papers from Ken Dill and students that deal with these approaches. And i don't think you missed them, they turned up after a discussion on Maximum Entropy Production principles. -- rec -- On Thu, Jun 30, 2011 at 11:00 AM, Steve Smith sasm...@swcp.com wrote: On 6/30/11 8:02 AM, Nicholas Thompson wrote: Thanks, Eric, for taking the question seriously. I will study your answer with care. Ask a simple question, and waddya get? Another day older and deeper in (conceptual) debt! Eric says: All these flow problems that we talk about are not described by equilibrium ensembles; they are ensembles of processes. Of course, everybody says that, but apparently most of the time people don't act as if saying that should then carry meaning for what they think afterward. (Like other mantras, its function appears to be to suppress pre-frontal cortex activity.) What a great insight! I wonder how much of our blather here on this list is in fact crafted or selected for it's ability to suppress pre-frontal cortex activity? Wow! While we *think* we are promoting pre-frontal activity, we may very well be supressing it! I wonder if there is a simple heuristic for recognizing mantras in clear text? Going recursive here, I wonder about the brain-state/chemistry that might be involved in our (my!) propensity for (near) idle speculation about things I know just enough about to be dangerous. There seems to be something very soothing about this kind of speculation... hmmm? As for the rest of your (Eric) response! What a lot to unpack... I mostly get process vs equilibrium ensembles, spaces of histories and and some of the entropy talk
Re: [FRIAM] symmetry breaking
Nick, hi, This time I really, really am under the gun and have no business answering. But you are not being foolish. You are pushing correctly on a set of statements that are not a principle. As Steve and Peter and others have said, the only way to properly handle this is actually to work out a full solution, and then figure out what global properties the particular solution is expressing, and I haven't done that, so I can't provide anything that counts as an adequate answer. But a couple of points that I think are relevant. The intuition you are pushing: Water up high has gravitational potential energy. That by itself doesn't get turned into heat, so it doesn't directly dissipate. If the water can fall, the potential can be converted to kinetic energy, and from there, various frictional effects can indeed convert the bulk-motion of the water to thermal motion. This is why you would be looking for phenomena that both speed the rate of fall, but then afterward also speed the slowing of average motion through frictions to disorderly motion. Internal turbulence etc. are all good pathways through which that can happen. On use of dissipation: I think that, to the extent that it ever means anything in these conversations, dissipation means the conversion of energy from a mechanical form into a thermal form that goes into the entropy. I will say in a moment why that usage in most conversations from Schroedinger and Brillouin onward, through Prigogine, are not reliable. But at least that statement is precise enough that it can be falsified. And sometimes it is okay; it's just that those sometimes are case-dependent. On other factors such as constraints: Yes, all the conversation about stirring has to do with the role of angular momentum, as well as potential energy, as a constraint on the configurations available to the system, and to the processes through which they can dissipate or do anything else. Any relaxation process, however described, will be constrained by whatever factors are put into its initial conditions, so inequivalent initial conditions need not lead to directly comparable downstream phenomena. Angular momentum that you put in by initial stirring must be transferred to the sink or the air, before the fluid can slow enough to reach the drain, and that takes time, because the transfer of angular momentum is mediated by boundary-layer dynamics, sink-shape effects, etc., just like everything else. On the reason the standard use of dissipation doesn't get you to principles: When people say the entropy, they usually mean the function which -- IN AN EQUILIBRIUM ENSEMBLE -- would be the proper measure of uncertainty or distribution of energy among degrees of freedom. All these flow problems that we talk about are not described by equilibrium ensembles; they are ensembles of processes. Of course, everybody says that, but apparently most of the time people don't act as if saying that should then carry meaning for what they think afterward. (Like other mantras, its function appears to be to suppress pre-frontal cortex activity.) A processes with states and flows has more that you can know about it than a process with the same states but without flows. This means that its uncertainty or distribution are more constrained -- because they are constrained by additional quantities -- than the equilibrium counterparts. Therefore, the function that is the entropy for an equilibrium ensemble will no longer generally be the correct measure of uncertainty or distribution for an ensemble of processes. The CONCEPT of entropy is still fine, and even the Shannon/Boltzmann definition in terms of probabilities can still be fine. But the probabilities come to be defined on spaces of histories rather than merely of states. The entropy function that then results from the Shannon/Boltzmann construction is then not generally the same function that would arise for any equilibrium ensemble. Likewise, the ways that constraints act over the course of histories, and the expression of that action in terms of _functional_ gradients of this new entropy function, will generally be new functional forms. In a limited set of cases, the starting- and ending-condition equilibrium ensemles are restrictive enough that one can get away without an explicit model of the dynamics, and then dissipation expressed in terms of the equilibrium entropy may predict correct descriptions. But in other cases, while the asymptotic beginning and ending configurations will continue to place bounds on what can happen, those bounds may be so loose that they are not directly informative, and one will be forced to go to an entropy function that is influenced by the dynamics, to identify what the true constraints are. To my knowledge, no systematic prescription exists to determine which systems will require a proper treatment, and which will be tractable with the entropy-production approximations a la Prigogine. But I do find it a
Re: [FRIAM] symmetry breaking
Thanks, Eric, for taking the question seriously. I will study your answer with care. All the best, Nick -Original Message- From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Eric Smith Sent: Thursday, June 30, 2011 8:35 AM To: The Friday Morning Applied Complexity Coffee Group Subject: Re: [FRIAM] symmetry breaking Nick, hi, This time I really, really am under the gun and have no business answering. But you are not being foolish. You are pushing correctly on a set of statements that are not a principle. As Steve and Peter and others have said, the only way to properly handle this is actually to work out a full solution, and then figure out what global properties the particular solution is expressing, and I haven't done that, so I can't provide anything that counts as an adequate answer. But a couple of points that I think are relevant. The intuition you are pushing: Water up high has gravitational potential energy. That by itself doesn't get turned into heat, so it doesn't directly dissipate. If the water can fall, the potential can be converted to kinetic energy, and from there, various frictional effects can indeed convert the bulk-motion of the water to thermal motion. This is why you would be looking for phenomena that both speed the rate of fall, but then afterward also speed the slowing of average motion through frictions to disorderly motion. Internal turbulence etc. are all good pathways through which that can happen. On use of dissipation: I think that, to the extent that it ever means anything in these conversations, dissipation means the conversion of energy from a mechanical form into a thermal form that goes into the entropy. I will say in a moment why that usage in most conversations from Schroedinger and Brillouin onward, through Prigogine, are not reliable. But at least that statement is precise enough that it can be falsified. And sometimes it is okay; it's just that those sometimes are case-dependent. On other factors such as constraints: Yes, all the conversation about stirring has to do with the role of angular momentum, as well as potential energy, as a constraint on the configurations available to the system, and to the processes through which they can dissipate or do anything else. Any relaxation process, however described, will be constrained by whatever factors are put into its initial conditions, so inequivalent initial conditions need not lead to directly comparable downstream phenomena. Angular momentum that you put in by initial stirring must be transferred to the sink or the air, before the fluid can slow enough to reach the drain, and that takes time, because the transfer of angular momentum is mediated by boundary-layer dynamics, sink-shape effects, etc., just like everything else. On the reason the standard use of dissipation doesn't get you to principles: When people say the entropy, they usually mean the function which -- IN AN EQUILIBRIUM ENSEMBLE -- would be the proper measure of uncertainty or distribution of energy among degrees of freedom. All these flow problems that we talk about are not described by equilibrium ensembles; they are ensembles of processes. Of course, everybody says that, but apparently most of the time people don't act as if saying that should then carry meaning for what they think afterward. (Like other mantras, its function appears to be to suppress pre-frontal cortex activity.) A processes with states and flows has more that you can know about it than a process with the same states but without flows. This means that its uncertainty or distribution are more constrained -- because they are constrained by additional quantities -- than the equilibrium counterparts. Therefore, the function that is the entropy for an equilibrium ensemble will no longer generally be the correct measure of uncertainty or distribution for an ensemble of processes. The CONCEPT of entropy is still fine, and even the Shannon/Boltzmann definition in terms of probabilities can still be fine. But the probabilities come to be defined on spaces of histories rather than merely of states. The entropy function that then results from the Shannon/Boltzmann construction is then not generally the same function that would arise for any equilibrium ensemble. Likewise, the ways that constraints act over the course of histories, and the expression of that action in terms of _functional_ gradients of this new entropy function, will generally be new functional forms. In a limited set of cases, the starting- and ending-condition equilibrium ensemles are restrictive enough that one can get away without an explicit model of the dynamics, and then dissipation expressed in terms of the equilibrium entropy may predict correct descriptions. But in other cases, while the asymptotic beginning and ending configurations will continue to place bounds on what can happen, those bounds may be so loose that they are not directly
Re: [FRIAM] symmetry breaking
Oops! I need to make an emendation: It was Roger Critchlow who sent all the Dill papers whenever-it-was, perhaps a year ago. I remain equally grateful, this time to the right person. Many thanks, Eric 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
Re: [FRIAM] symmetry breaking
On 6/30/11 8:02 AM, Nicholas Thompson wrote: Thanks, Eric, for taking the question seriously. I will study your answer with care. Ask a simple question, and waddya get? Another day older and deeper in (conceptual) debt! Eric says: All these flow problems that we talk about are not described by equilibrium ensembles; they are ensembles of processes. Of course, everybody says that, but apparently most of the time people don't act as if saying that should then carry meaning for what they think afterward. (Like other mantras, its function appears to be to suppress pre-frontal cortex activity.) What a great insight! I wonder how much of our blather here on this list is in fact crafted or selected for it's ability to suppress pre-frontal cortex activity? Wow! While we *think* we are promoting pre-frontal activity, we may very well be supressing it! I wonder if there is a simple heuristic for recognizing mantras in clear text? Going recursive here, I wonder about the brain-state/chemistry that might be involved in our (my!) propensity for (near) idle speculation about things I know just enough about to be dangerous. There seems to be something very soothing about this kind of speculation... hmmm? As for the rest of your (Eric) response! What a lot to unpack... I mostly get process vs equilibrium ensembles, spaces of histories and and some of the entropy talk, but am lost entirely on the topic of competing definitions of diffusion and it's precise relevance to this conversation... I'll give it my best shot though... dig a little deeper. I believe This is the Dill paper http://www.google.com/url?sa=tsource=webcd=1ved=0CBYQFjAAurl=http%3A%2F%2Fwww.dillgroup.ucsf.edu%2Fdl_papers%2FJCP2008Stock.pdfrct=jq=ken%20dill%20caliberei=_KIMTqSdNZT2swOvkLCQDgusg=AFQjCNF1QwcT3WourQaoLPT8EvAX1tfG4wsig2=0YsVN6J1NJanyAIYt3rszQcad=rja you refer to? I missed it the first time it was passed around I think. Or with your just-out re-attribution to RC, rather than NT And here is a lecture by Dill http://mitworld.mit.edu/video/537/ at MIT that might be more accessible by some? - Steve 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
