Colin, Two quick thoughts:
1. Your description of ion channels sounds a LOT like a Hall-effect device. I suspect that ion channels may be **VERY** sensitive to magnetic fields!!! Aside from implementing natural compasses, Hall-effect may be a part of their computational functionality. Note in passing that Hall-effect devices are FAST, so it may not be beyond reason that there might be some really high-speed analog computation going on in ion channels!!!. 2. You might be able to model some of the things your are thinking about with a fish tank full of salty water and structures made of Play Dough. You will also need a battery, a voltmeter, and some insulated wire with exposed ends. Electrolytic tanks have been used to model many complex EM things. Steve On Tue, May 12, 2015 at 2:04 AM, Colin Hales <[email protected]> wrote: > Hi again, > Yes the *potential* drops off as 1/r and the dipole as 1/r^2 as you say. > Not the field intensity. That is 1/r^2 and 1/r^3 resp. But this is > irrelevant. Don't confuse potentials with the fields. I wrote an article > on this > > Hales, C. G. and S. Pockett (2014). "The relationship between local > field potentials (LFPs) and the electromagnetic fields that give rise to > them." *Frontiers in Systems Neuroscience* *8*: 233. > http://journal.frontiersin.org/article/10.3389/fnsys.2014.00233/full > > The line source you mention doesn't actually contribute to the field > system in any functional sense for subtle reasons. This is another broken > aspect of the thinking. > > You have to deal with the actual physics of ions in water and in ion > channel pores in space and the details of the charge transport as applied > through Maxwell's equations,,..NOT the physics of a model. Just because a > resistor is in a model and predicts voltages correctly does not mean that > the fields in nature are the fields of a resistor. In general: the > physics of the field system is not the field system of the circuit element > models. > > The *same total * *current *has 3 lives: 1) Intracellular 2) > Transmembrane and 3) extracellular. > > In terms of contribution to the actual functional field system (2) > Dominates both (1) and (3). > > To see this: > > The ion transit speed and transport dynamics in the extracellular space > and intracellular space is 10000-50000 times *slower *than transmembrane *and > radically diffuse and diluted*. Almost non existent as a charge *density*. It > is the electric field that matters and when you do the math the field due > to the axial current (line source) is negligible because the current does > not involve a functional charge density even though the total current is > the same. ergo negligible E field contribution. > > In contrast, the transmembrane portion (of the exact same total current) > is radically confined to an Angstrom-level pore-width and along a path > length in a very particular direction 20-50 times longer than anywhere else > in tissue (through the thickness of the membrane). The transmembrane ions > are like bullets from hundreds of *parallel* machine guns in comparison > to traffic in the extracellular space and the intracellular space, where > ions are confined by water to almost zero path length and bounce in totally > randomised directions. None of this detail is in any circuit element model. > > It is charge *density and *current *density *(not current) that matter > for field generation. Charge density and current density are radically > different in each phase of ion transport (1), (2) and (3). Hence they > produce different fields. > > I am doing the full convective simulations of this over the next few > months. The failure, over decades, to look at the actual ion transport > mechanisms in the ECS and ICS and contrast them with the transmembrane ion > channel current has caused yet another stuff-up in understanding the field > system. The only people that actually know this are in *microfluidics* > and it is a modified form of microfluidics equations that I will solve > (with the water flow velocity set to zero). > > When you actually compute the magnitude of the real electric field > produced by the transmembrane ion traffic as totalled by tens of 1000s of > cells within in a 500um radius sphere they can easily add up to that needed > to effect each other even though the field drops off as 1/r^3. This is a > very short distance. It is the *gradient* of the potential, not the > potential that matters. The E field is a very complex vector sum that > dominates even though it drops off faster with distance. The E field in the > Lorentz force does the work. > > You can choose a million exotic circuit elements and find a part of a > neuron who's potentials may be modelled with it. That does not mean that > the neuron 'is' one of those things. Its not diodes yet there's lots of > diode like things going on. It's not a resistor yet there are lots of > behaviours that obey resistor-like laws. You can view neurons through a > model-lens made of SR or bar fridges and hockey sticks and igneous rocks > that produces the same voltages and current. .... and on and on and > on.....and you are welcome to do that to suit what you are doing. In none > of it does it tell you what the actual natural material is doing in > relation to EM fields. > > That is why I build what I will build. I build what the brain does, not > what a model of the brain does. I can't help it if this is the way the > brain is. If I found anything different I'd be building that instead. > > When I compute (1), (2) and (3) I'll send the results to the list. It'll > be a while. > > Congrats! My work here of showing you the potholes on the road to > understanding EM field origins is done. :-) I think we are officially > grokked out. > > cheers > colin > > > > > > > > > On Tue, May 12, 2015 at 3:23 PM, Steve Richfield < > [email protected]> wrote: > >> Colin, >> >> You have described regenerative operation, which is a near-field sort of >> thing and not capable of sensing small things at a distance where signals >> drop off as r^2, HOWEVER, I just realized that the field from a line >> (rather than a small dipole) source, like from an axon rather than an ion >> channel, drops off LINEARLY with distance. Hence, at distances that are >> short compared with axon length, regeneration might be enough to work. >> >> I just didn't see any need to stick with a purely regenerative model, >> when SR completely sidesteps the limits of regeneration AND there is plenty >> of evidence of SR in neurons. >> >> Regarding the past tense of grok - it becomes past tense when you can no >> longer grok - like when you get Alzheimer's or die. Until then it is an >> active sort of thing, like your fields, and so remains in the present. >> >> Steve >> >> >> >> >> >> >> On Mon, May 11, 2015 at 8:09 PM, colin hales <[email protected]> wrote: >> >>> Hi Steve, >>> The fields originate in a dissipative evanescent dipole that exists as >>> long as the action potential transmembrane current exists. EM field >>> feedback is in modulation of distant network signal timing and propagation >>> phenomena. Positive, negative whatever. It emerges at a higher >>> organizational level that has nothing to do with the physics originating >>> the fields. >>> >>> The magnetic field comes from a brief transmembrane current. The >>> electric field is a result of a battle between diffusion and >>> electromigration in the immediate vicinity of the ends of the very same >>> transmembrane current. If the transmembrane current is large and long >>> enough (requiring lots of collocated ion channels)... Then this causes a >>> depletion of ion charge on one side and accretion on the other....dipole >>> big enough to contribute to signaling at distance. It exists as a >>> dissipative cascade that is momentary, stops and then equilibrium is >>> chemically restored. Think of it as a capacitor discharge, stop, recharge. >>> In the EM field feedback the moment of discharge is determined in part by >>> impinging E field from elsewhere in the tissue. That may constitute a >>> positive feedback from distances a long way away. >>> >>> Positive feedback also exists within the longitudinal propagation of the >>> action potential. That is regenerative. Models usually depict this as >>> resulting from potentials and currents. I suspect that it's actually the >>> magnetic field that is very strong at distances of um. That magnetic field >>> tickles distant ion channels located in the same membrane (because the >>> magnetic field is strongest in the plane of the membrane) into the >>> conformation change that causes the next transmembrane current that >>> then..... But that magnetic field role something I'm speculating ...doing >>> simulation over the coming months. Regardless of how you think is positive >>> feedback involved in action potentials. >>> >>> So there's 2 kinds of +ve feedback. One in action potential propagation >>> down the membrane, one impacting timing transversely through the tissue at >>> the speed of light. >>> >>> I hope one day to make hardware that does both in the same way the brain >>> does it. >>> >>> Lots of + feedback. Right there. >>> >>> I already have this in the design. So where does this lack of positive >>> feedback issue come from? I can't see it. >>> >>> There's pencils standing up and falling down in vast numbers in the >>> design already. So to speak. SR is just not telling me anything I need, at >>> least in early replication efforts. >>> >>> Are we grokked yet? And is that the past tense of grok? >>> >>> Cheers >>> Colin >>> ------------------------------ >>> From: Steve Richfield <[email protected]> >>> Sent: 10/05/2015 6:34 AM >>> To: AGI <[email protected]> >>> Subject: Re: [agi] Re: Starting to Define Algorithms that are More >>> Powerfulthan Narrow AI >>> >>> Colin, >>> >>> Here you have made exactly the same point I was trying to convey in my >>> immediately-preceding posting on SR... >>> >>> On Sat, May 9, 2015 at 3:08 AM, colin hales <[email protected]> wrote: >>> >>> <snip> >>> >>> >>>> Replicating voltages is _not_ replicating fields. Gauge invariance >>>> makes the relationship degenerate. An infinity of different field systems >>>> can produce the same voltages. That very degeneracy is the reason why >>>> electric circuit theory exists! >>>> >>> >>> This SAME gauge-invariance would doom your ion-channel theory UNLESS >>> there is some sort positive-feedback mechanism at work to extract the >>> INFORMATION from the EM field. If not SR, then WHAT? >>> >>>> >>>> I am rather excited by the recognition of something that is so obvious >>>> and whose lack fits the failure etiology of half a century perfectly, >>>> including the lack of the actual empirical test that is needed to justify >>>> neglecting the fields as essential physics. Neglecting the fields is >>>> entirely accidental. >>>> >>> >>> I agree. >>> >>> Steve >>> >>> >>>> >>>> >>>>> >>>> >>>> >>> *AGI* | Archives <https://www.listbox.com/member/archive/303/=now> >>> <https://www.listbox.com/member/archive/rss/303/11721311-f886df0a> | >>> Modify <https://www.listbox.com/member/?&;> Your Subscription >>> <http://www.listbox.com> >>> *AGI* | Archives <https://www.listbox.com/member/archive/303/=now> >>> <https://www.listbox.com/member/archive/rss/303/10443978-6f4c28ac> | >>> Modify <https://www.listbox.com/member/?&;> Your Subscription >>> <http://www.listbox.com> >>> >> >> >> >> -- >> Full employment can be had with the stoke of a pen. Simply institute a >> six hour workday. That will easily create enough new jobs to bring back >> full employment. >> >> *AGI* | Archives <https://www.listbox.com/member/archive/303/=now> >> <https://www.listbox.com/member/archive/rss/303/11721311-f886df0a> | >> Modify <https://www.listbox.com/member/?&;> Your Subscription >> <http://www.listbox.com> >> > > *AGI* | Archives <https://www.listbox.com/member/archive/303/=now> > <https://www.listbox.com/member/archive/rss/303/10443978-6f4c28ac> | > Modify > <https://www.listbox.com/member/?&;> > Your Subscription <http://www.listbox.com> > -- Full employment can be had with the stoke of a pen. Simply institute a six hour workday. 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