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Post by speakertoanimals on Oct 11, 2010 17:03:27 GMT 1
Only if you're too stupid to understand basic english.
I said that rotatory motion is non-intuitive, hence is a prime breeding-ground for pseudo-science. Which is what I can see developing here, if we're not careful.
Whereas Newtons equations, if carefully applied, explain everything that has ever been observed.
And indeed, when it comes to measuring subtle effects of relativity (the effect of a rotating, gravitating mass like the earth), the builders of Gravity Probe B constructed the most accurate gyroscopes ever made -- and published results agree with relativity.
I'll sit back and wait for the predictable gyroscopes and anti-gravity nonsense...................
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Post by Progenitor A on Oct 11, 2010 17:49:32 GMT 1
Only if you're too stupid to understand basic english. Then I must be particularly stupid - I have always struggled with English
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Post by carnyx on Oct 12, 2010 1:33:09 GMT 1
@sta #13
A classic post!
Most people find the behaviour of things that spin, both mysterious and fascinating. It has nothing to do with intuition or otherwise. If anything, the attempts to model them are in turn fascinating (see Feynmann) .. and even those who have the mathematical descriptions at their fingertips, still find gyroscopic behaviour fascinating and inspiring.
But with your you appear to see mathematics as a means of dispelling mystery (and also fascination).
I may remind you that engineers have exploited the so-called pseudoscience surrounding gyroscopic behaviour. Helicopters, autopilots, ship's stabilisers are some obvious examples. Now, do you think they arose from the equations or did they arise from the understanding of the physical behaviour of rotating objects?
... and maybe because the behaviour of things that spin is so interesting and pervasive, that this is where new stuff is most likely to emerge from.
But back to the puzzle; even if you restated the relationships in Post 1 in rotational terms, you still would not have got it!
And neither would olmy. Better luck next time
(PS olmy; I like your statement " Newtons equations, if carefully applied, explain everything that has ever been observed" ... does that go for ADT as well?)
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Post by speakertoanimals on Oct 12, 2010 13:12:05 GMT 1
No, I think you'll find they have exploited the science of gyroscopic behaviour.
You don't seem to know what pseudoscience means (surprise, surprise) plus seem to feel that fascinated ignorance is more compelling than understanding.
It is certainly more useful to those that want to peddle pseudoscience, as all the quantum woo-woo merchants know.
The things about gyroscopes is that it is only the charlatans don't want people to know how Newtons equations describe seemingly impossible things, such as you being able to lift a heavy gyroscope as long as it is spinning (Eric Laithwaite claimed that at first, but later admitted that Newtons equations could explain it). Why? Because they want you to remain bamboozled so you'll invest in their newly-patented gyroscopic anti-gravity machine...................
The whole point about science of any sort is that it seeks to dispel mystery (where did animals come from, where did rocks come from, why do gyroscopes do what they do?), whereas others seem to think that ignorance and puzzled fascination is bliss. Fine, if you want to remain ignorant and gaze stupidly about saying wow a lot, but those of us who do science find instead that the MORE we explain, the MORE fascinating things become, rather than the converse.
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Post by carnyx on Oct 12, 2010 16:27:35 GMT 1
No, STA,
They exploited gyroscopic behaviour per se, and not 'thescienceofgyroscopicbehaviour'. If they had gone to you first, nothing would have happened. (Which was the point of setting the puzzle in the first place, in order to establish that fact)
.And thanks for stating your own personal motivation so clearly;
"The whole point about science of any sort is that it seeks to dispel mystery"
Snag is, you aren't very good at it. You seem to generate more mystery than you dispel, despite wanting at the same time to increase the level of fascination.
But the phenomenon remains, despite your depredations! A young boy is actually lifting a spinning weight he ordinarily would not be able to lift. Check his muscles ... it is a REAL effect. The fact that it cam be 'explained' by a set of mathematical formulae based on sets of axioms of one sort or another ... is merely incidental. And do tell us about Laithwaite's 'patent anti-grav' scam! I missed that. How much grant-money did he abstract on that one? Was he a role-model for the AGW Scientists?
Anyway, I hope you enjoyed the puzzle. Here is a sequel;
Assuming that 'anti-grav' refers to the apparent reduction in the local gravitational effect on a mass, could it be simulated (within limits) by; a) reducing the mass? b) reducing the accelerative force on the mass? c) increasing the value of 't'? d) reducing the angular momentum of the mass?
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Post by speakertoanimals on Oct 12, 2010 19:07:27 GMT 1
It is far from incidental! No one is saying that it isn't a real effect. The INTERESTING thing is that it actually follows from Newtons laws. So, most people can kind of get F=ma and action and reaction, but when it comes to rotatory motion, out intuition is just no good at all.
I think you'll find BTW, that engineers use Newtons laws if they want their stuff to actually work.........................
Back to Newton. These aren't just some arbitrary axioms, but a wonderfully concise set of laws for classical mechanics. Their universality is pretty amazing -- given the law of gravity as well, you can understand Keplers laws of planetary motion. Here on earth, you use Newtons laws all the time, from working out why bridges don't fall down, what happens when you slide down a slope, why your ladder stays against the wall, what happens when you play snooker, and so on and so on.
Describing all this as incidental is just nonsense. Newtons laws aren't actually mathematical formulae, which suggests you have never actually looked at them................
But our knowledge has now gone beyond Newton. The gyroscope depends on stuff like conservation of angular monetum, which is implicit in NEwtons laws, but not explicit.
So, WHY conservation of momentum, angular momentum and energy? Turns out this has a REALLY interesting answer. I mean REALLY, really interesting, significant on a cosmic scale.................
Because the laws of physics don't depend on position, orientation, or time. This is a totally general result, aside from the fact that we don't know exactly what the ultimate laws of physics are, or only know approximately in certain situations.
That is where we have got to from Newtons laws, and from the peculiar way gyroscopes behave. That as far as the universe is concerned, no direction is special.
Saying any of this is incidental is just saying that you don't actually care about any of the science, you'd rather sit around instead and go wow a lot. Except the rest of us, I'm afraid, go a bit further than that, and after umpteen demonstrations of the gyroscopic effect, went off to think about WHY gyroscopes behaved like that, what it had to do with snooker, falling cannonballs, and the orbits of the planets and the precession of the equinoxes here on earth, why we have seasons, and why the sun spins, why the planets go round the sun in the same way, why we have the plane of the ecliptic, why we can only see one side of the Moon, and so on and so on -- because ALL of these relate to angular momentum.
And rather than all that, you'd prefer a 'mystery'............You have an astounding lack of vision or imagination..............
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Post by carnyx on Oct 12, 2010 21:42:44 GMT 1
@sta,
Bravo! You are terrific when aroused, I must say!
Just a couple of points;
You will admit that there are a couple of 'givens' and at least one fiction at the heart of his massive intellectual construction, as there must be in all works of art. There is the axiom of 't' as a independent variable, whose rate is uniform and invariate. Indeed his mathematics of 'fluxions' or calculus could not exist without it. There is also his definition of mass, force, and also the fiction of uniform motion in a straight line which we know cannot be found in nature.
And in a way, it is a shame that the oversimplification of his billiard-table F = M x A stuff should have been propagated for so long, but in the era that followed, these simple formulae and the associated metamechanics was too useful in daily life.
I say this because we all know that forces are really torques, and angular momentum is where the action is. And so stuff like gyroscopic behaviour and atoms and molecules that spin at fantastic rates and so must exhibit these effects of OTOH unyielding infinitely huge mass, and OTOH no mass at all, would perhaps be more 'second nature' had he started with rotational mechanics.
And when we look at angular momentum and how it is distributed in the solar system for example, I agree that it is really fascinating.
And there is your:
...which I found a refreshing statement, not because of the point about time, but because it show that physics is not over, and there is a lot more mystery still to be worked on.
I have to say, that having experienced a singularly good engineering education in these matters, plus a lifetime in the practice of them, I still do actually go off and think about all the things you mentioned.
So STA, you must take my posts seriously because they are meant to amuse.
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Post by speakertoanimals on Oct 13, 2010 12:34:42 GMT 1
Your comment about calculus is nonsense, because the mathematically legitimacy of derivatives has nothing at all to do with the physical assumption that time exists. You can have spatial derivatives too you know.
Your point about uniform motion is also total nonsense. Once we have decided we are using forces, we have to start by defining what happens when no net force acts. Rather than cannot be found in nature, it is actually quite simple to set up situations where it is approximately true. So even if the actual no forces case doesn't exist, we can still approach it by a limiting process, and logically we have to do so, to get anywhere.
Forces are defined quite simply as the thing that produces acceleration. Mass is defined quite simply as well.
Yes, there IS an important underlying assumption, that time is universal. In relativity, this is modified, but einstein still retained F=ma. And he also retained the first law in effect. So continuing in a state of uniform motion is in effect a straight line in flat spacetime -- einstein just modified this to be a geodesic in curved spacetime, so the spirit of Newton is retained.
Before you start wittering on about time, you really ought to learn the basics of classical mechanics..............
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Post by carnyx on Oct 13, 2010 15:37:31 GMT 1
@sta#22
You absolute relativism seems only to be surpassed by your relative asbolutism!
A preposterous statment, I fear. Didn't Newton invent the mathematical process which produced derivatives!.. specifically to help his analysis of planetary orbits? And, he had to make the prior assumption ( i.e. axiom) that 'time' was a physical scalar quantity ... like Length .. which we (and he) knew was a fiction .. but was necessary to get his mathematics to work ...
And of course, you actually agree!
In other words Newton's time is axiomatic ... a given! 't' as a <necessary fiction>
Now, there is;
You seem to have got in a frightful muddle, here! I will repeat what I was actually saying;
Uniform motion and a straight line are both idealised fictions ... nether exists in nature. And he was very careful to pick these two cases, because it conveniently aligned the action to get rid of the 'L' term .. .. because as we all know that real life, force are really torques (or couples) and come with a length term.
Another way of looking at his genius is that he 'disappeared' the fulcrum by careful choice of case to get rid of the L term so he could stay in this linear world ... so, as you eloquently put it, he could 'get somewhere'.
Well, as F is really is a special case of ML, and so is equal to E, then we can get to E = 1/2 M.V^2. But as it is really ML = 1/2M.L^2, then there is not as much excitement to be had, is there?
But to end with a bad joke to match your crude insult; the idea of conservation of momentum extends into the world of rotation, and so so to the conservation of angular momentum.
And it follows that if there is only so much angular momentum in the universe, then in a metaphysical sense, all interaction between bodies basically comes down to winding each other up!
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Post by speakertoanimals on Oct 13, 2010 16:13:49 GMT 1
Note the word mathematical. The mathematical validity of the calculus remains, even if the laws of nature don't rest on differential equations.
No, it fitted in with experimental observation.
you have still to produce a shred of evidence that time is any less physical than length.
This is totally irrelevant, because with physical processes, we can APPROACH these ideal limits, hence our physics has to describe, for starters, what happens in this limit, before we can say anything about what happens when we move away from this limit to real cases. WIthout saying that without forces, there is no acceleration, we cannot say that an additional force produces acceleration.
So, if I observe that increasing the force on an object, increases its acceleration, and that the acceleration increase in proportion to the force, then we have the observed fact that:
F = ma + constant
SO, we HAVE to determine what the constant is, if we want to use this relation. And that constant just says what happens in the limit of zero force, AND has an effect for non-zero force. Hence totally physical, even if we can't measure the constant directly, we can infer its value form other experiments.
No more mysterious than extrapolating a straight line, and finding the intercept is zero.
No it isn't.
Work done dW is Fdl, but that doesn't make the force energy, but the gradient of the work done wrt distance. And force is an easier concept to MEASURE directly than energy.
As I said before, you know nothing about maths, or basic classical mechanics, and the more you say, the clearer that becomes.
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Post by carnyx on Oct 13, 2010 17:14:27 GMT 1
STA
- Check out who invented calculus, and why.
- The 't' of the equations is not an independent physical quantity. It is a relative counting between ordered sequences of events .. (as you pointed out on another thread). It is a number, representing itself. It not a quantity of anything except the ticks of a counter.
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Post by abacus9900 on Oct 13, 2010 19:17:59 GMT 1
Ah, but history seems a bit uncertain about that!
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Post by olmy on Oct 14, 2010 7:46:54 GMT 1
The 't' of the equations is not an independent physical quantity. So you say. Still no evidence, still no reasoning, just blind assertion against the evidence. It is a relative counting between ordered sequences of events... Oh, for goodness sake, THINK! What is it that gives them an order?
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Post by carnyx on Oct 14, 2010 8:31:04 GMT 1
olmy, You really can't say that your 't' of the equations finds a physical manifestation in say, a set of <i>rosary beads</i> .... You ask; Ah!, do you mean that changing the order of just two of those beads, (or the precedence of two events) means that I have made time go backwards? Now in the mathematical 't' of the formulae, yes. But in the physical world, it is just a change of position. You are confusing a sequence of numbers with a physical thing. For example the Tempo of music can only exist as a relative comparison between at least two seperate sequences, and is a result of general agreement between individuals. BTW, do you dance?
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Post by olmy on Oct 14, 2010 8:53:37 GMT 1
olmy, You really can't say that your 't' of the equations finds a physical manifestation in say, a set of <i>rosary beads</i> .... You are confusing a sequence of numbers with a physical thing. For example the Tempo of music can only exist as a relative comparison between two seperate sequences. BTW, do you dance? You really aren't THINKING. It is pretty much the most basic observation you can make to say that we live in a three dimensional world with the passage of time. Your bizarre, faith based witterings about events and counting them ( measuring time) does nothing to detract from that observation. Yes, there is no absolute value of 't', any more than you can assign an absolute value of 'x', 'y' or .z' to a point in space. Yes, we now know, it is relative to each observer in various ways - so is distance. None of this means that is it not a real, observed aspect of the world. We know, from real evidence in the real world, that our approach is broadly correct (otherwise it is the most amazing coincidence in history). If you would actually THINK, just for a moment, about what you are saying, you would realize that how your 'ordered events' NEED time. You can only order things if you can assign some property to each one that is ordered. An arbitrary event (say the arrival of a pendulum at one end of its swing, or a point in the orbit of the Earth) has no such property of itself - each one is the same as any other. The only thing that distinguishes one such event from another is TIME.
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