What keeps electrons spinning around their nucleus?
in [Relativity]
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From: mmeron on 31 Mar 2005 19:00 In article <Pine.LNX.4.44.0503310705060.25009-100000(a)dill.hep.wisc.edu>, Creighton Hogg <wchogg(a)hep.wisc.edu> writes: > > >On Thu, 31 Mar 2005 mmeron(a)cars3.uchicago.edu wrote: > >> In article <Pine.LNX.4.44.0503301941040.20954-100000(a)dill.hep.wisc.edu>, Creighton Hogg <wchogg(a)hep.wisc.edu> writes: >> >Indeed this is the case as I've seen it as well. I learned >> >it on my own in 10th grade because I was bored and >> >frustrated. There's no reason why kids that age can't >> >handle it. >> > >> Try to explain this to the school boards (and be prepared to face >> charges of elitism). > >I don't really understand why people fight so hard against >teaching math and science earlier or why they fight so hard >against making students learn it at all. It's like some >kindof cultural block against it. I sometimes think there's >become some kindof two-tone deafness about children and >children's education. Sometimes it seems like people think >you can be loving, caring, and accepting of whatever a child >does, or you can be a sadistic monster that tormets children >day and night with nothing in between, and since telling a >child that they did something wrong isn't being accepting... > Well, yes, there is lots of this in our "therapeutic society". People had been fed lots of garbage over the years, from various self proclaimed education experts. All this stuff how kids should grow in a "loving, pressure free environment". Which is nonsense because absent some pressure kids do not mature. And we see lots of this around. Mati Meron | "When you argue with a fool, meron(a)cars.uchicago.edu | chances are he is doing just the same"
From: mmeron on 31 Mar 2005 19:27 In article <424c44bb.178645040(a)news.ucalgary.ca>, kmuldrezw(a)ucalgazry.ca (Ken Muldrew) writes: >mmeron(a)cars3.uchicago.edu wrote: > >>In article <Pine.LNX.4.44.0503301941040.20954-100000(a)dill.hep.wisc.edu>, Creighton Hogg <wchogg(a)hep.wisc.edu> writes: >>> >>>On Wed, 30 Mar 2005 mmeron(a)cars3.uchicago.edu wrote: > >>>> This said and done, in any US public school I know, calculus is taught >>>> (not to all, only the students who opt to take it) in grade 12 (with a >>>> possibility of a bright 11 grader taking it as en elective). >>> >>>Indeed this is the case as I've seen it as well. I learned >>>it on my own in 10th grade because I was bored and >>>frustrated. There's no reason why kids that age can't >>>handle it. >>> >>Try to explain this to the school boards (and be prepared to face >>charges of elitism). > >Sit the school board down and force them to do a page of long division >of polynomials and then a page of derivatives. Hopefully there's at >least one person who can do it Optimist:-) >and he or she will convince the others that they have made a grave error >in the curriculum. > Or, not. Depends on the local population and the type of people running for a school board. It is a positive feedback situation. Mati Meron | "When you argue with a fool, meron(a)cars.uchicago.edu | chances are he is doing just the same"
From: Tom Capizzi on 31 Mar 2005 23:49 "TomGee" <lvlus(a)hotmail.com> wrote in message news:1112308130.498530.137080(a)f14g2000cwb.googlegroups.com... > > Tom Capizzi wrote: >> "TomGee" <lvlus(a)hotmail.com> wrote in message >> news:1112244079.328719.15960(a)f14g2000cwb.googlegroups.com... >> > >> > Tom Capizzi wrote: >> >> "TomGee" <lvlus(a)hotmail.com> wrote in message >> >> news:1112061355.884198.62110(a)g14g2000cwa.googlegroups.com... >> >> > >> >> > PD wrote: >> >> >> > SNIP >> >> >> >> >> >> Centrifugal forces don't exist. They are mistakes of perception > and >> > no force >> >> actually pushes out. >> >> >> >> >> > Not so. The inertial force of a mass wants it to go straight but > the >> > gravitational force wants it to turn and if an orbit results the > net >> > force is on the side of gravity but just enough to pull it into > orbit. >> >> Inertial force only exists in the rotating frame. Inertia causing a > body to >> move in a >> straight line is a property of a non-rotating frame, as such straight > lines >> appear >> to be curves in a rotating frame. You're mixing frames of reference. >> >> > So you say, but saying so don't make it so, remember? Or did you > forget again? Talk is cheap but support requires heavy labor. Cite > something (and no websites unless they make the same claim you make > above plus the explanation for it which you failed to provide above. Do it yourself. You need the practice. Anybody can google for a definition just like I did. Take your pick of thousands of references. > Why should the inertial force of the 1st law be excluded from rotating > frames, in view of thefact that Newton makes no such distinction. You should reread the 1st Law. >> >> >> >> >> >> > SNIP >> >> >> >> >> >> >> >> > 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] >> >> >> >> >> > That's what I said, velocity is a vector. It is also "speed", but > that >> > is not what he means. If he is saying that the forces are imposed >> >> He is saying exactly what he means: the radius of the circle is at > right >> angles >> to the velocity (vector). It is inappropriate to claim anything is >> perpendicular >> to speed. >> >> > Of course. That's what I said. >> >> > SNIP >> >> > perpendicular to the speed, if he means to use velocity for speed, > that >> > would be nonsense, as I noted above. If he means to say that the >> > direction of the mass quantity is tangent to the path of the object >> > (trajectory), that too makes no sense. >> >> Makes sense to me. At any given point on the trajectory of any object > the >> direction is defined to be the tangent at that point. >> >> > I won't belabor this point any further, but he said, in effect, that > the object moves in the direction which the object moves. Given an arbitrary trajectory (which is neither straight nor circular) just how do you define where the trajectory points at some arbitrary position? >> >> >> >> > SNIP >> >> >> >> > If magnitude and quantity had the same meaning, we would have use > for >> > only one and not both. >> >> Since you want to quibble about definitions, what in Gee-speak do you > claim >> is the difference? Besides, have you never heard of synonyms? >> >> > Why is it okay for others to use synonyms in physics but not for me to > use them? In physics it is the finer points which seem to win the day, > they tell me. If you want to know the difference, look them up > yourself and then let me know. Again, I did. One is used to define the other. And where are you using synonyms that weren't okay? Maybe they weren't really synonyms. >> >> >> >> > >> >> >> 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. >> >> >> >> >> > If you actually understood what is being said you would know > circular >> > motion is not a straight line. Or do you agree with Silly there > that >> > objects in circular motion, orbits or orbitals, will continue in > such >> > motion even when the forces maintaining them in such motion are >> > removed? >> >> You misrepresent what others say and expect agreement on your error? >> >> > I do not misrepresent what others say. What they say is in black and > white for all to read. You disagree with me so you claim I am > misrepresenting what others say. If I did that, aren't you smart > enough to show others where I have done that? It is well known that you put words in people's mouths so you can argue your point or ridicule them. >> >> >> >> >> >> > SNIP >> >> > >> >> >> >> 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. >> >> > SNIP >> >> >> it seems you already had the answer you wanted, but were trying to >> > bait a >> >> troll's trap. >> >> >> >> >> > Hey, I did not ask the questions. You seem to think that the > question >> > was what keeps it moving? It was not. He asked what keeps it > moving >> > _around the nucleus_, as you correctly state above. You don't seem > to >> > see the distinction between those two questions, but that is not my >> >> Your error. I explicitly pointed out that the two questions are > different >> above. >> >> > You did? Why? I already did that. Do you think the OP did not want > to know what keeps it moving around the nucleus? Why did he ask that > then? >> >> >> Earlier you made a spurious claim about speed when the poster > specifically >> used the term velocity. >> >> > No, I did not. You misunderstood what I said. I said that using speed > was inappropriate if he meant that definition of velocity, and you > agree to that. He didn't use "speed", you did. He said "velocity" and he meant it and used it appropriately. Your objection was not valid. >> >> >> Below you make reference to the irrelevant "free >> electron". Nobody is talking about free electrons but you. >> >> > Yes, because I am using them to make my point which shows you/he > misunderstood the question from the gitgo. I agree with the other poster who suggested we consult the original author. >> >> >> > fault. Something keeps free electrons moving, and as free > electrons, >> > they are not then moving around any nucleus. Since the question > was >> > that specific, so was my answer. >> > >> > > TomGee >
From: jmfbahciv on 1 Apr 2005 07:36 In article <424c467c.179093927(a)news.ucalgary.ca>, kmuldrezw(a)ucalgazry.ca (Ken Muldrew) wrote: >jmfbahciv(a)aol.com wrote: > >>In article <3avtadF6bq14rU1(a)individual.net>, >> "robert j. kolker" <nowhere(a)nowhere.net> wrote: >>> >>>jmfbahciv(a)aol.com wrote: > >>>> they can't teach science because there is only 1 microscope/ >>>> 10 students. That's an awfully high ratio even though the >>>> ads want you to think that it's too low. When I went to >>>> high school, I estimate the ration to be 1/100. >>> >>>While the relative scarcity of lab equipment >> >>1 in 10 is not a scarcity. I would call it wastage. > >You're forgetting the undisciplined nature of today's schoolchildren. I didn't know it existed. >The worst that can happen to them for misbehaving is they go on >holiday for a while. 1/100 microscopes will turn into 0 working >microscopes and 1/100 broken microscopes within the first week of >classes. Then we would have a fixit class. Which would probably start to get the kids interested. Horrors! [emoticon slaps mouth] I just did a swear. > ..And although this situation creates a niche for a useful and >productive course in scientific instrumentation (where the students >could fix all the broken stuff), Yup. Definitely. I just saw a CSPAN show (I got bored trying to learn about foreign policy work on its other channel). The work involved creating protheses for military personnel who lost body parts is fascinating. Getting those kids started fixing instrumentation would be very useful. I'd sign up for class if they really taught how to fix stuff. > .. such a course will never appear in a >modern high school. Yea, well. It's a good thing teachers don't want me to help. I hate bored kids; they're PITAs. /BAH Subtract a hundred and four for e-mail.
From: jmfbahciv on 1 Apr 2005 07:49
In article <1112296912.137057.152400(a)o13g2000cwo.googlegroups.com>, "PD" <pdraper(a)yahoo.com> wrote: >jmfbahciv(a)aol.com wrote: >> In article <3avtadF6bq14rU1(a)individual.net>, >> "robert j. kolker" <nowhere(a)nowhere.net> wrote: >> > >> > >> >jmfbahciv(a)aol.com wrote: >> > >> >> >> >> The Mass. board of education is now trying to add science >> >> as part of the high school graduation requirement. The >> >> year proposed was 2008 but news broadcasts are now saying >> >> it can't happen until 2010. Listen for the whinging from >> >> teachers' unions. One of them is already running ads that >> >> they can't teach science because there is only 1 microscope/ >> >> 10 students. That's an awfully high ratio even though the >> >> ads want you to think that it's too low. When I went to >> >> high school, I estimate the ration to be 1/100. >> > >> >While the relative scarcity of lab equipment >> >> 1 in 10 is not a scarcity. I would call it wastage. >> >> > .might impact the quality of >> >lab based science instruction there is no shortage of blackboards or > >> >overhead viewscreen devices. The theoretical aspects of physics and >the >> >associated mathematics can be taught with the material resources >> >currently at hand. >> > >> >On the other hand biology and chemistry does not a substatial >laboratory >> >practice component to be taught properly. If one does not dissect >the >> >worm or frog one has no sense of the asymmetry of internal structure >of >> >complicated organisms. >> >> Each student does not need biology and chemistry lab equipment >> 7x24. A class of 30 use the lab for 45 minutes at a time. Multiply >> by number of classes per day. ...although I have been noticing that >> the school buses are now dumping kids at 14:15 lately. That means >> that a kid gets 4 hours of class? >> > >You are right, of course, but you assume that students in a classroom >will be doing different things at different times, Not at all. You assign two to three kids to each piece of lab gear. It's a team effort...just like Real Life. Now whether each has to write an individual report or the group submits one report is an option for the teacher depending on what he wants teach with the lab exercise. > .. which means that the >teacher must orchestrate and monitor at least two different activities >simultaneously. This is often unrealistic and results in bedlam. A >science class is a plenary experience and not a parallel experience, by >default, *unless* someone is very creative and structured with a >curriculum that supports parallelism. You're doing lab work. Not only is that a parellel effort; it's an effort with an unknown outcome. No wonder kids are having problems; they're getting managed to death. > ..As any conference organizer can >tell you, it is exponentially harder to arrange parallel sessions than >plenary sessions. This is where things begin to bog down with teachers. You don't have three sessions in the same room. If you have to hang blankets from the ceiling you divide the room into functional blocks. In high school a lab is a very small block. There a reason that lab classes and lecture classes are held separately. /BAH Subtract a hundred and four for e-mail. |