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29 November 2024 00:53
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| Asked by: |
Nitro |
| Subject: |
oposite but not equal |
| Question: |
Dear all,
I can see from your homework that I shall have to go over one of the precession lessons with you again.
Now sit up straight everyone, and Rameses, stop doing that and pay attention.
We have all observed that an unspun gyro acts just like a dead weight and that if you suspend one end of its shaft on the proverbial Eiffel tower, piece of string or whatever takes your fancy, lift the axis to horizontal, then release the unsuspended end, the non spun gyro will like a good, obedient, Newtonian fellow, drop under the force of gravity.
So far so good everyone?
We have also all observed that a well spun gyro (Yes, and well spotted, Ram, I did say “well spun” and I’ll come to that shortly.) released under the same circumstances does not drop, to all intents and circumstances. Indeed it acts in a seemingly ill behaved non Newtonian manner. Its axis, to all intents and purposes, does not drop at all (Yes! Yes! Ram, I know you think it does but you’re wrong, and I’ll get to that shortly too) and it rotates exactly around the centre of its support point (Now, Ram, you must stop interrupting!). This is because the angular momentum of the gyro’s spin in one plane converts the force (in this instance gravity – the still unexplained force. Unless, of course, Higgs was right, and that surely cannot be. No one who can call a sub atomic particle a “boson” can be taken seriously! Why! You’d be having physicists coming up with daft names like “quark” and “charm” next, I shouldn’t wonder!) applied to change its axial angle in one plane produces an axial angular change in an other plane, at right angles to the force. This, to save hurting you young pupil’s brains, is simply referred to as “precession”. Precession you will note, Ram, does not need energy to be applied to the axial angle, merely a force. (No, Ram, the gyro doesn’t need to drop a little, or at all, to cause precession – you haven’t been paying attention, have you?) This, of course has been arranged by God or Darwin or whoever is in charge nowadays, so that precession does not to upset Newtonian fundamentalists – in this particular example – as there is no energy involved in the precession to be conserved. The conservation laws ARE completely messed up, along with several others, in other examples of precession but that is for much later. Although you are all doing very well, we must proceed at a pace with which the slowest can keep up.
Right, Class! We have now observed, above, two states of a gyro.
One, unspun, where it acts like a bog-standard Newtonian mass, exhibiting Newtonian reactions to an applied force and thus, in this first state, would try to produce centrifugal displacement were it to be rotated round a fixed point (are you seeing what you missed yet, Ram).
And a second state; when the gyro is spun, precesses and places its centre of precessional rotational mass (weight) effect straight down through the centre of its pivot support. It is, after all the supporting pivot that is permitting gravity to apply its force causing precession. There is not a pivot point somewhere else permitting gravity to apply its force, causing precession, is there?
What has been missed by some of you (I wish you would stop lifting your desk lid, pretending to look for something, Harry, I know you’ve got a comic book hidden in there) is that there is a third, intermediate, state that progresses from Newtonian to gyrodynamic. Within this third state a gyro progresses from acting like an ugly duckling lump of matter to a magnificent “flying” gyro. In this third state it is neither a Newtonian lump or a gyro yet at the same time it displays some of the properties of a Newtonian lump AND a gyro. This third state is what can cause a gyro with no “Newtonian” (non rotating) mass (Yes, Ram, it’s called a top) to produce a (non gyrodynamic) centrifugal force on its pivot. Now there is no need to cry. Many people have difficulty at this part of the curriculum and there is no shame for misunderstanding this (though if you had paid more attention instead of picking your nose and examining the contents of your handkerchief, David, you probably would have understood this and progressed from simple math to something admired, like making useful things in the woodwork class.). Far better people, in their humble opinion (or ITHO as I am given to understand they say on something called Twitter), have missed this as well and it hasn’t affected their exam results in the slightest. Why! Only the other day, I was reading that young Emma Wislon in 4b (Dr Huge Hunt’s unruly class) had been given a doctorate despite getting this part of her thesis completely wrong – don’t tell me the Department of Education isn’t dumbing down exams to massage up the pass figures!
This third state is why a top or gyro with a long axial length from its centre (Yep! English spelling derived from the French – that’s why it’s called English?) of rotating mass to its pivot, for example, or when slowed by friction and nearing the end of its gyrodynamic display starts to become more and more like an ordinary lump as it is less and less able to precess its own mass against the force aplied to change its axial angle. At this stage it can be observed to wobble (you can call this nutation if you wish) as it alternates between gyrodynamic and Newtonian (it’s actually positive feedback of the increasing centrifugal forces being precessed) and displays pronounced centrifugal force trying (and if it is on an air table- succeeding) to displace its pivot point. Of course you don’t need to wait until it has slowed down, you could just increase the force causing precession by, for example, increasing the weight/force changing its axial angle, or simply increase the leverage that its weight/force is acting upon by extending its axial arm. This can produce a force acting to change the axial angle that goes beyond what the gyro can totally precess so it “Newtons” (new verb!) some of its mass. This, you will observe, is what daft young Emma did and, I suspect, is what you did Ram on your shoddy air table/top test, you old dafty, you. As we went over and over in the air table lesson; even on a well spun gyro, any non spinning mass must be carefully counter balanced or it will seem like the centre of rotation is offset from the support pivot. How do you expect to learn if you keep wandering onto community webchat sites instead of doing your homework? I swear you’ll end up in the I.T. software business if you're not careful.
As you all know I was educated at AS Neil’s (emporium of wisdom) Summerhill and am, therefore, averse to administering corporal punishment (and rote skooling) because of the rift it creates between teacher and pupil. However Headmaster Kidd would like to see you, Ram F. and you, Harry K., after class. And Harry, take that comic book out of the back of your trousers.
Kind regards,
Love and Laughter
NM
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| Date: |
20 May 2012
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Answers (Ordered by Date)
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| Answer: |
Glenn Hawkins - 20/05/2012 18:56:02
| | | Very good Blaze,
Blaze: “A well spun gyro released does not drop. Its axis does not drop at all. This is because the angular momentum of the gyro’s spin in one plane, converts the gravity force into something else.”
Glenn: “Sorry, but a reaction cannot happen, until an action has happened.”
Blaze: “Precession does not need energy to be applied to the axial angle, merely a force. the gyro doesn’t need to drop at all, to cause precession.
Glenn: “Action is the result of energy expended. The wheel exhibits gyroscopic effects, only because inertia is tilted to a different plain. Deflections that drive everything are the result of tilting, not of force, not of pressure, but of action. Nothing can happen, until the wheel drops into it's first deflection. . . which is truly instant.
Blaze: “there is no energy involved in the precession to be conserved.”
Glenn: “Whenever mater is in motion it carries momentum, which is potential energy to be released. I have released this energy and the way is not completely simple.”
Blaze: “. . . there is a third, intermediate, state that progresses from Newtonian to gyrodynamic. Within this third state a gyro progresses from acting like an ugly duckling lump of matter to a magnificent “flying” gyro. In this third state it is neither a Newtonian lump or a gyro yet at the same time it displays some of the properties of a Newtonian lump AND a gyro.”
Glenn: 'Your idea is interesting.'
Blaze: “This third state is what can cause a gyro with no “Newtonian” (non rotating) mass to produce a (non gyrodynamic) centrifugal force on its pivot. “
Glenn: “Yes!”
Blaze: “This is because the angular momentum of the gyro’s spin in one plane, converts the gravity force into something else.
Glenn: For your especially good effort I will post my theory of what your 'something else' is, which I believe is the mechanics of precession.
Glenn: “I have enjoyed the fine humor and color. My friend Ram and Erma and my actual friend Harry K. probably enjoyed it even more, they being embraced with the complete enumeration of it. I found your technical writing difficult and in some areas flawed to my belief, but all of it is interesting.
Glenn: “Are you using an abstract metaphor, an idealism in reference to Neal's Summerhill School, or did you attend. Are you German? I think you are joking, but who could know?”
id est
Neal's Summerhill has been running continuously since 1921and has not changed fundamentally since it started. Its success in providing a happy environment for kids and producing well-balanced men and women, stands as a continuing proof of Neil’s notion that `The function of the child is to live his own life – not the life that his anxious parents think he should live, nor a life according to the purpose of the educator who thinks he knows best.'
Glenn,
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| Report Abuse |
| Answer: |
Harry K. - 20/05/2012 21:00:35
| | | Hello Nitro,
The Comic book has the title «Nitro's laws» and I love it because it's so funny!
It's amazing how less you understand about really gyro dynamics...
However, I enjoyed your “lesson“ although there were no needful things to learn about gyro dynamics. I think it's wasted time to try to explain people like you something, doesn't matter about anything...
In this sense,
Harry
My actual friend Glenn,
You should observe AND read more carefully!
The author of this thread isn't BLAZE...
Greetings from Mr. Alzheimer. :-)))
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| Report Abuse |
| Answer: |
Glenn Hawkins - 20/05/2012 22:16:42
| | | Dear Harry,
I stand stupefied, rebuffed and corrected. I would leave out the possibility of Alzheimer for a while. Nothing like that shows up in your writing. If I had known who posted, I might not have answered, but he does have a good wit and a fine gift for humor. Perhaps you could appreciate the house, if it fell on somebody else. ; - )))
Now then, what did you think of my post? Did you disagree? With what? Not much I think.
Cordially Yours,
Glenn,
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