What keeps electrons spinning around their nucleus?
in [Relativity]
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From: Ken S. Tucker on 29 Mar 2005 06:50 To Mati et al mmeron(a)cars3.uchicago.edu wrote: > In article <Xns9627C5AEB62D6WQAHBGMXSZHVspammote(a)130.39.198.139>, bz <bz+sp(a)ch100-5.chem.lsu.edu> writes: > >mmeron(a)cars3.uchicago.edu wrote in > >news:8B12e.18$45.3391(a)news.uchicago.edu: > > > >> In article <Mo12e.16031$C7.902(a)news-server.bigpond.net.au>, "Bill Hobba" > >> <bhobba(a)rubbish.net.au> writes: > >>> > >>><mmeron(a)cars3.uchicago.edu> wrote in message > >>>news:XQ02e.15$45.3352(a)news.uchicago.edu... > >>>> >coordinates, but I think what is misleading is to call the correction > >>>> >terms "forces". > >>>> > >>>> Only if you attach more meaning to the term "force" than it deserves. > >>> > >>>Ahhhhhh. Yes. As Feynman says it is half a law. It gains its full > >>>meaning when combined with other laws and/or concepts such as Coulombs > >>>law or the introduction of non inertial reference frames. > >>> > >> Yes, it is a rather complex issue. I wrote some stuff about it in the > >> past, here, but I never kept a copy. But it certtainly needs some > >> sort of broad framework, to make sense. > > > >Especially when someone keeps insisting that force is always the result of > >acceleration > > Cause, not result. > > > and that without acceleration (as for example when a gyro > >precesses at a constant rate, or when a mass moves at a constant velocity > >because it is overcoming drag or friction) there is no force and no work. > > > Where there is net force, there is acceleration. The F in Newton's > law is the total (i.e.) net force acting. Since forces are vectors, > it is perfectly possible to have different non-zero forces to sum up > to a zero net force. > > If I put your finger in a vise and squeeze, your finger is being acted > upon by two forces, equal and opposite. The net force is zero and > your finger is going nowhere. Which by no means mean that since the > net is zero, there are no observable +++ >(or, for that matter, audible, > i.e. loud screams) effects present. >Mati You use a vise? I get by with a hammer, nail and a thumb...and swear words. Daryl looks like he's introducing a neat borderline GR approach with his d(e_i)/dt, to define some of the sematics. To the point using physics. Experiment confirms radiation is photonic, quantized and discontinuous. Prior to Planck's Quantum Theory hypothesis, it was *classically* thought an electron would spiral in to the nucleus *continuously* emitting radiation. In simple math that spiral would require P = q*E>.v> (scalar product) q is the charge, E> is the Electric field vector of the nucleus and v> is "q"'s velocity relative to E>, and "P" is Power. That P = dp/dt with p = system energy. Experimental confirmation of QT finds, P=0. In terms of Lorentz's force, f_0 = q*F_0i U^i = (Coulomb force = q*F_0i)*(velocity = U^i) = 0, as a scalar product, aka outer multiplication. Force x velocity is Power. Hence QT finds by hypothesis f_0=0. In terms of SpaceTime we can re-write that f_0 = m * dU_0/ds = 0 where m=1, and U_0 = dx_0/ds, A_0 = dU_0/ds is an acceleration, and means there is no force in the direction of time, and so no acceleration in the time direction, which sounds very reasonable to me. I call that a "quantum geodesic", because we see how EM as Lorentz Force uses, mixes with QT, and the A_0 =0 GR predicts. My blurp is why I think QFT is based on GR and that the're compatible. Of course there's always more detail. Regards Ken S. Tucker
From: Harry on 29 Mar 2005 07:34 <mmeron(a)cars3.uchicago.edu> wrote in message news:7K52e.21$45.3808(a)news.uchicago.edu... > In article <Xns9627C5AEB62D6WQAHBGMXSZHVspammote(a)130.39.198.139>, bz <bz+sp(a)ch100-5.chem.lsu.edu> writes: > >mmeron(a)cars3.uchicago.edu wrote in > >news:8B12e.18$45.3391(a)news.uchicago.edu: > > > >> In article <Mo12e.16031$C7.902(a)news-server.bigpond.net.au>, "Bill Hobba" > >> <bhobba(a)rubbish.net.au> writes: > >>> > >>><mmeron(a)cars3.uchicago.edu> wrote in message > >>>news:XQ02e.15$45.3352(a)news.uchicago.edu... > >>>> >coordinates, but I think what is misleading is to call the correction > >>>> >terms "forces". > >>>> > >>>> Only if you attach more meaning to the term "force" than it deserves. > >>> > >>>Ahhhhhh. Yes. As Feynman says it is half a law. It gains its full > >>>meaning when combined with other laws and/or concepts such as Coulombs > >>>law or the introduction of non inertial reference frames. > >>> > >> Yes, it is a rather complex issue. I wrote some stuff about it in the > >> past, here, but I never kept a copy. But it certtainly needs some > >> sort of broad framework, to make sense. > > > >Especially when someone keeps insisting that force is always the result of > >acceleration > > Cause, not result. > > > and that without acceleration (as for example when a gyro > >precesses at a constant rate, or when a mass moves at a constant velocity > >because it is overcoming drag or friction) there is no force and no work. > > > Where there is net force, there is acceleration. The F in Newton's > law is the total (i.e.) net force acting. Since forces are vectors, > it is perfectly possible to have different non-zero forces to sum up > to a zero net force. > > If I put your finger in a vise and squeeze, your finger is being acted > upon by two forces, equal and opposite. The net force is zero and > your finger is going nowhere. Which by no means mean that since the > net is zero, there are no observable (or, for that matter, audible, > i.e. loud screams) effects present. Right. Active forces (or how to call them, I think Newton called them impressed forces) cause acceleration. But a centrifugal force is a reaction force to a centripetal force, which is caused by a change in direction. I wouldn't describe such as "pseudo force" or "fictional" force, as that gives the wrong impression that no real force is exerted. In reality such forces are real enough to break your neck! Newton also didn't call them "pseudo" or "fictional", AFAIK; he just called them innate/inertial forces. Harald
From: Tom Capizzi on 29 Mar 2005 08:07 "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message news:Xns962827C438D5EWQAHBGMXSZHVspammote(a)130.39.198.139... > "Tom Capizzi" <etianshrdlu(a)verizon.net> wrote in > news:BX52e.46657$db6.1238(a)trndny02: > >> >> "bz" <bz+sp(a)ch100-5.chem.lsu.edu> wrote in message >> news:Xns9627C5AEB62D6WQAHBGMXSZHVspammote(a)130.39.198.139... >>> mmeron(a)cars3.uchicago.edu wrote in >>> news:8B12e.18$45.3391(a)news.uchicago.edu: > ... >> >> I know the feeling - I've pushed many a vehicle on streets that weren't >> always >> that level. But the work you are doing is expended overcoming the force >> of friction. On level ground you are doing no work against gravity. > > Right. but I am still doing work. Tires, etc., have rolling friction. > As long as I must exert a force to keep the car moving, I am doing work in > the physics sense. > >> People often >> claim that holding a book at a fixed height off the ground is also work. >> Here >> they are in error. There is no motion and no friction. In spite of the >> fact that >> your arm gets tired, there is no work being done, unless the book is >> actually >> lifted to a higher elevation. > > Right. I understand this. Of course if my muscles tremble slightly and the > book moves up and down, oscillating around the fixed height, THEN work is > being done, isn't it? > In that case elevation is changing, so it fits the definition of work against gravity. > > > > -- > bz > > please pardon my infinite ignorance, the set-of-things-I-do-not-know is an > infinite set. > > bz+sp(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: Tom Capizzi on 29 Mar 2005 08:41 "TomGee" <lvlus(a)hotmail.com> wrote in message news:1112061355.884198.62110(a)g14g2000cwa.googlegroups.com... > > PD wrote: >> TomGee wrote: >> > PD, >> > >> > didja ever learn anything in school? >> > >> > 3rd grade Physics: Centrifugal force. >> > >> > Don't ask me to explain that to you. Go to class and ask your >> teacher. >> > >> > TomGee >> >> Tom, you can either keep babbling nonsense or you can start asking >> honest questions. >> >> A few things: >> 1. The force *inward* in central motion is called centripetal force, >> not centrifugal force. >> >> > So you made it through 2nd grade, so what? No one has said otherwise, > yet you keep on repeating that. >> >> >> The electrostatic attraction between electron >> and proton is an example of a centripetal force. >> >> > So what? Did anyone ask you to give an example of it? And the basis > of that centripedal force is??: Em attraction twix the electron and > the protons, as I said at first. >> >> >> 2. There is no such thing as centrifugal force, strictly speaking. It >> is a misleading term for a "false force" that has no true agent to >> provide it. >> >> > There, you see? You just learned that and you failed to understand > what is false and what is real! How many times will I have to tell you > that your measurements are false but not the forces which pull in and > push out. Call them eggs if you wish to be contrary, who cares? They > exist and no one has yet agreed with you that they do not exist. Centrifugal forces don't exist. They are mistakes of perception and no force actually pushes out. >> >> >> If this comes as a shock to you, perhaps it's because >> you're relying on the physics you learned in the 3rd grade. >> 3. In circular motion, you'll note that the velocity is tangent to > the >> circular trajectory, perpendicular to the radius of the circle. Both >> the true, centripetal force and the false, centrifugal "force" are >> along the radius of the circle, perpendicular to the velocity. >> >> > Velocity is a vector but you are using it to mean "direction". Speed > cannot be tangent nor perpendicular to anything, so you're babbling > now. Talking about yourself again? Vector: 2. (Math.) A directed quantity, as a straight line, a force, or a velocity. Vectors are said to be equal when their directions are the same their magnitudes equal. Cf. Scalar. [1913 Webster] >> >> There is >> no way that a force that is perpendicular to the velocity can change >> the magnitude of the velocity, nor does it help in any way to > maintain >> the velocity. >> >> > Mygawd Im talking to a child! There is no magnitude in velocity! It > is a measure of the rate of change of position of something wrt time, > speed, and direction. See above definition of vector. Clearly it has magnitude. You don't know what you are talking about again. > >> 4. Newton's 1st law should also have been taught to you in 3rd grade >> physics, and you should be reminded that, even in the absence of >> forces, objects in motion tend to stay in motion. >> >> > I can't believe you are so ignorant as to claim that the 2nd law allows > objects to remain in orbit if all forces are removed. I let that > foolishness go by the first time you said it, to keep from making you > look sillier, but it is you who brings that onto yourself, not me, with > your absurdities. Look again. It says 1st law. If you actually read the 1st law you would know that it says motion "in the same direction", that is to say a straight line, unless acted on by unbalanced forces. >> >> >> Now, if you find any of this to be intuitively wrong, then your > problem >> is not with special relativity, it's with 3rd grade physics. If you >> would like corroboration that any of the above is true or false, then >> simply itemize the thing you think is wrong and ask the newsgroup. >> >> > All but a few have dared to agree with me or disagree with you, but, as > I said in my first post in this thread, I find it incredible that the > first 8 posters could not answer a simple question properly. Either > they all think you're the greatest thing since Einstein or they will > agree to anything so long as they don't have to agree with me. > The question was what keeps the electron spinning around the nucleus, not what keeps it attracted. Maybe they are the same thing to you, but they are actually perpendicular directions. In physics, perpendicular components, even of the same vector, are independent. If you wanted to know what attracts the electron, you should have asked a better question. Of course, it seems you already had the answer you wanted, but were trying to bait a troll's trap.
From: Gregory L. Hansen on 29 Mar 2005 09:28
In article <RD52e.20$45.3912(a)news.uchicago.edu>, <mmeron(a)cars3.uchicago.edu> wrote: >In article <d2abun$65m$3(a)rainier.uits.indiana.edu>, >glhansen(a)steel.ucs.indiana.edu (Gregory L. Hansen) writes: >>In article <Rj12e.16030$C7.2138(a)news-server.bigpond.net.au>, >>Bill Hobba <bhobba(a)rubbish.net.au> wrote: >>One objection I would have in trying too hard to teach it "the right" way, >>besides confusing the students, is that too often it denies the things >>they know. Everyone knows what centrifugal forces are, nobody is confused >>on the fact that you feel it in something that's spinning and you don't >>feel it in something that's moving uniformly. And then these eggheads >>come along and say centrifugal forces don't actually exist, although the >>layman knows those nonexistent forces seem to work pretty well when the >>laundry machine hits the spin cycle. And the layman isn't wrong. >>Insufficient centripetal force to retain the water and sufficient >>centrifugal force to expel the water are separated by a simple >>transformation. The layman doesn't think of it in that way, but he knows >>that things happen when you spin. Does the egghead actually accomplish >>anything by trying to excise the word "centrifugal" from the language? >> >There is this bit of fun to get from telling people >"what you thought to be true is not so, the truth is quite different" >(with the implied "I'm smarterr than you're, nah nah nananah":-)). I think exactly that every time I see "glass is a liquid" come floating around. Glasses tend to be harder, stiffer, and more creep resistant than most crystalline solids, and without the redeeming quality of (eventually) dripping through a funnel. But long after the words "solid" and "liquid" were defined based on bulk properties, atoms were discovered and then it was noticed that glass isn't crystalline, and ever since, weenie egghead wanna-be's have been spouting "Glass is a liquid, what you thought was true is wrong, I'm smarter than you are, nah nah nananah!" Thereby sharing with people the factoid that glassy materials lack long-range order, but otherwise mystifying the process of science. >And while, in an honest moment, I'll admit that there is some (albeit >low) enjoynment to be derived from this, basing the teaching of a >discipline on this is not advised. > >>Should we skip the chapter on Newtonian gravitation in favor of the >>equivalence principle? > >Good point. > >Mati Meron | "When you argue with a fool, >meron(a)cars.uchicago.edu | chances are he is doing just the same" -- "No one need be surprised that the subject of contagion was not clear to our ancestors."-- Heironymus Fracastorius, 1546 |