Let's Take A Vote...
in [Design]
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From: Phil Hobbs on 25 Jul 2010 08:49 George Herold wrote: > On Jul 24, 6:37 pm, Phil Hobbs > <pcdhSpamMeSensel...(a)electrooptical.net> wrote: <snip> >> <dim-memory-on> >> >> The Sun is nearly electrically neutral, because it continuously streams >> plasma, which is electrically conductive. If there were any really big >> excess charge, there would be an excess of one polarity in the solar >> wind until it was dissipated. (There may be some solar processes that >> act to maintain a smallish charge on the Sun, but it won't be much.) >> >> The whole Earth (solid plus atmosphere) is also nearly electrically >> neutral, due to being immersed in a conducting medium (the solar wind). >> >> The solid Earth has a net negative charge of something like 1E10 >> coulombs, iirc, and the atmosphere a nearly equal positive charge, >> maintained by thunderstorms. (Google will have a better handle on it, I >> expect.) > > Another great chapter from the Feynman lectures. Volume 2, chapter? I don't know--I've never read them. (I've been meaning too forever, because everyone says they're amazing, but haven't got there so far.) Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: Phil Hobbs on 25 Jul 2010 08:54 George Herold wrote: >>>> John >>>> [1] extra credit: how big would they be? >> Objects have both self-capacitance and mutual capacitance, so it's quite >> sensible to talk about a capacitor with only one lead. In Gaussian >> units, the self-capacitance of an isolated sphere of radius r >> centimetres is r. (The CGS unit of capacitance is the centimetre.) >> >> One cm ~= 1.12 pF, so 330,000 pF is about 30 km radius. That's quite a >> big reel! >> >> - Show quoted text - > > (Or get Phil to check my math.) > > George H. He's having enough trouble with his own recently--it took two tries this time. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal ElectroOptical Innovations 55 Orchard Rd Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
From: John Larkin on 25 Jul 2010 10:58 On Sun, 25 Jul 2010 02:10:02 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Sat, 24 Jul 2010 15:46:37 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > >>On Sat, 24 Jul 2010 16:50:09 -0500, John Fields >><jfields(a)austininstruments.com> wrote: >> >>>On Sat, 24 Jul 2010 13:48:57 -0700, John Larkin >>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>> >>>>On Sat, 24 Jul 2010 15:23:53 -0500, John Fields >>>><jfields(a)austininstruments.com> wrote: >>>> >>>>>On Sat, 24 Jul 2010 10:32:36 -0700, John Larkin >>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>> >>>>>>On Sat, 24 Jul 2010 12:25:15 -0500, John Fields >>>>>><jfields(a)austininstruments.com> wrote: >>>>>> >>>>>>>On Sat, 24 Jul 2010 10:13:48 -0700, John Larkin >>>>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>>>> >>>>>>>>On Sat, 24 Jul 2010 11:49:38 -0500, John Fields >>>>>>>><jfields(a)austininstruments.com> wrote: >>>>>>>> >>>>>>>>>On Sat, 24 Jul 2010 08:30:43 -0700, John Larkin >>>>>>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>>>>>> >>>>>>>>>>On Sat, 24 Jul 2010 09:04:41 -0500, John Fields >>>>>>>>>><jfields(a)austininstruments.com> wrote: >>>>>>>>>> >>>>>>>>>>>On Sat, 24 Jul 2010 08:15:03 -0500, John Fields >>>>>>>>>>><jfields(a)austininstruments.com> wrote: >>>>>>>>>>>On F>> >>>>>>>>>>>>On Fri, 23 Jul 2010 17:38:45 -0700, John Larkin >>>>>>>>>>>><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>>>>>>Charge is measured in coulombs. Force is measured in newtons. So how >>>>>>>>>>>>>is charge "a measure of force"? >>>>>>>>>>>> >>>>>>>>>>>>--- >>>>>>>>>>>>news:2apl46hr8s01os8dv1aipdm19bcf64nec4(a)4ax.com >>>>>>>>>>> >>>>>>>>>>>--- >>>>>>>>>>>Oh, and the first sentence of the cited Wikipedia article reads: >>>>>>>>>>> >>>>>>>>>>>"Electric charge is a physical property of matter which causes it >>>>>>>>>>>to experience a force when near other electrically charged matter." >>>>>>>>>>> >>>>>>>>>>> >>>>>>>>>>>JF >>>>>>>>>> >>>>>>>>>>If you experience a pig, does that make you a pig? >>>>>>>>> >>>>>>>>>--- >>>>>>>>>That's just a silly diversionary tactic; measuring a force doesn't >>>>>>>>>make you the force. >>>>>>>>>--- >>>>>>>>> >>>>>>>>>>Look at the SI units if you want to determine if things are the same. >>>>>>>>> >>>>>>>>>--- >>>>>>>>>That's just another silly diversionary tactic. >>>>>>>> >>>>>>>>Were you ever taught dimensional analysis? >>>>>>>> >>>>>>>>Obviously not. Give it a try: >>>>>>>> >>>>>>>>http://en.wikipedia.org/wiki/Dimensional_analysis >>>>>>>> >>>>>>>>The basic concept is that you can test all sorts of relationships for >>>>>>>>plausibility by reducing their SI units. If the units don't agree, the >>>>>>>>things can't be equal. Newtons aren't coulombs, so charge can't be >>>>>>>>force. >>>>>>> >>>>>>>--- >>>>>>>No one said it was. >>>>>> >>>>>> >>>>>>You did: >>>>>> >>>>>>>>On the other hand, if Larkin's right and energy is conserved but >>>>>>>>charge isn't, then since charge is a measure of force, unbalanced lost >>>>>>>>charge might be able to be used for propulsion. >>>>> >>>>>--- >>>>>Ah, now I see. >>>>> >>>>>You can't tell the difference between: "charge is force" and: "charge >>>>>is a measure of force." >>>>> >>>>>JF >>>> >>>> >>>>You might read this >>>> >>>>http://en.wikipedia.org/wiki/Dimensional_analysis#Commensurability >>>> >>>>since it's the easiest part of the article to understand. >>>> >>>>Engineers do sometimes break the rules and add non-commensurable >>>>units, like designing a foldback power supply that limits the sum of a >>>>voltage and a current. Addition is a poor substitute for >>>>multiplication, but it's a lot easier to do with cheap parts. >>> >>>--- >>>Yawnnnnnn... >>> >>>And, has nothing to with the _fact_ that charges attract or repel each >>>other and that those attractions and repulsions are _mechanical_ in >>>nature and can be measured using any convenient system and converted >>>into any other convenient system as required. >>> >>>You do agree that one newton is equal to about 0.1020 kg wt or 0.2248 >>>pounds avoirdupois, yes? >>> >> >>"kg wt" is not an SI unit, so no. The units don't conform, so the >>quantities can't be equal. SI units were inventented to clarify things >>like this. >> >>If by "pounds avoirdupois" you mean lbf, pounds force, yes. The >>relation there is a dimensionless scaler, so is OK. > >--- >As usual, you try to dodge the point, which is that electric charges >generate mechanical forces, by trying to steer the discussion into >blind alleys. Charges CAN generate force, under certain conditions, but charges ARE NOT forces. The qualification "certain conditions" means that knowing charge alone is insufficient to determine any force. Two like charges in space repel, but you can't know how much unless you know the distance between them. You need to know the coulombs AND the meters distance between them to calculate force. So coulombs aren't force, and you can't measure force in coulombs. The dimensional units just don't work. They don't work any more than measuring distance in amperes works. It simply doesn't make sense. In the real world, if you can't get the units to conform, you're going to be seriously handcapped as regards doing serious engineering. Coulombs as a measure of force is fuzzy thinking, because you can't actually calculate or predict anything on that basis, and engineering is about getting the amounts right. You can build a doghouse with no math, but not a skyscraper. I'm not dodging any point, I'm trying to pound it into your head, and you insist on being wrong. You can't measure force in coulombs. Try reading the Wiki thing again. It's important. John
From: Nunya on 25 Jul 2010 12:42 On Jul 25, 5:49 am, Phil Hobbs <pcdhSpamMeSensel...(a)electrooptical.net> wrote: > George Herold wrote: > > On Jul 24, 6:37 pm, Phil Hobbs > > <pcdhSpamMeSensel...(a)electrooptical.net> wrote: > <snip> > >> <dim-memory-on> > > >> The Sun is nearly electrically neutral, because it continuously streams > >> plasma, which is electrically conductive. If there were any really big > >> excess charge, there would be an excess of one polarity in the solar > >> wind until it was dissipated. (There may be some solar processes that > >> act to maintain a smallish charge on the Sun, but it won't be much.) > > >> The whole Earth (solid plus atmosphere) is also nearly electrically > >> neutral, due to being immersed in a conducting medium (the solar wind).. > > >> The solid Earth has a net negative charge of something like 1E10 > >> coulombs, iirc, and the atmosphere a nearly equal positive charge, > >> maintained by thunderstorms. (Google will have a better handle on it, I > >> expect.) > > > Another great chapter from the Feynman lectures. Volume 2, chapter? > > I don't know--I've never read them. (I've been meaning too forever, > because everyone says they're amazing, but haven't got there so far.) > > Cheers > > Phil Hobbs > > -- > Dr Philip C D Hobbs > Principal > ElectroOptical Innovations > 55 Orchard Rd > Briarcliff Manor NY 10510 > 845-480-2058 > hobbs at electrooptical dot nethttp://electrooptical.net http://isohunt.com/lite/#q=feynman&p=1
From: Jim Thompson on 25 Jul 2010 12:57
On Sun, 25 Jul 2010 02:10:02 -0500, John Fields <jfields(a)austininstruments.com> wrote: >On Sat, 24 Jul 2010 15:46:37 -0700, John Larkin ><jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: > [snip] >>> >> >>"kg wt" is not an SI unit, so no. The units don't conform, so the >>quantities can't be equal. SI units were inventented to clarify things >>like this. >> >>If by "pounds avoirdupois" you mean lbf, pounds force, yes. The >>relation there is a dimensionless scaler, so is OK. > >--- >As usual, you try to dodge the point, which is that electric charges >generate mechanical forces, by trying to steer the discussion into >blind alleys. > >And all just to keep from having to admit error. > >How pathetically cheatful. How manic depressive. ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Spice is like a sports car... Only as good as the person behind the wheel. |