Spork, Humber's theory of operation is as follows:
"Humber is talking about the friction between the belt and the cart's drive wheels. He maintains that the wheels are slipping, resulting in a very delicate balance that supposedly keeps the cart in an "energy well".
Not quite. I have a mind of my own. The metaphors I use are my mental intuition pumps. From these, I build ideas and then modify and calculate.
Not slipping per se.
(1) Prop force is low. In this case, the friction is adequate to spin the propellor to whatever the belt dictates. Increasing the friction will not increase the prop load in this case.
(2) Wheels are slipping ( probably not) so more could be transmitted if the friction were to be increased.
Nothing delicate about the balance. It can hardly do otherwise. Study simple mechanisms. Pretty straight forward.
Any first year.....
The operator is not a pertubation, but a direct influence. The cart is placed at windspeed. Cartoon land.
He also claims the lack of KE in either direction as witnessed by the "groundside observer" is what keeps the cart from moving, because the cart would need to gain KE in order to move, thus the slipping of the wheels to prevent that gain. A perturbation as demonstrated by the spork poking only disturbs that balance momentarily, and if the treadmill was longer, the cart would return to the original position unaided. A flywheel would serve the exact same purpose as the propeller, and in fact the propeller can be reversed without changing the results of the treadmill test."
No scare quotes for groundside are necessary. I used them to make sure that you did not lose your way. IT IS THE LEGITIMATE OBSERVER. If not, then it is equally as valid, but better than yours. It holds with Newton and real world experience.
No, the balance is a system error. The rest is a 'passable' interpretation except that no work is the cause, friction the mediator.
He thinks that KE is an absolute, keyed to the earth, and that the only way to have the cart accurately modeled is to have the cart moving according to the ground at 10 mph. (Yet he laughs at the treadmill in a van that could be shown to do exactly that). He claims that the cart, as a result of being placed in the middle of the KE well with zero motion relative to the ground and therefore zero KE relative to the ground, cannot pull itself out of that zero KE condition and has an inherent balance as a result.
Not even close. The 'well' is notional. I do a lot of things, across many disciplines, that one comes from some studies of vibrating plates. Just my idea, but it is not literal. However, that is only a description of a cart on a belt, and has nothing to do with the failure as a model of a cart in wind. That failure results in the perceived behavior. I need not explain a failure, but I did, because I could see it, and worked it out for myself. I pass it to you. Take it or leave it.
He laughs like a drain at the van. Sol says, that "ignorant" people like me would expect the cart to fall off. Errr.. not quite. I expect that it will not, because the test is inert. It will never fail. DOH!.
There are no objects that move relative to the ground, that do not have KE.
The real cart moves w.r.t the ground, so it must have KE too, and in the model too. This MISUSE of frames, is not supported by Newton or anybody else, save cartoonists.
The the lack of KE is a system failure. The balance is a result of that failure.
He also thinks that because of that, a tether would cause the cart to develop a force which would show on the scale in a positive feedback loop. According to his theory, if the tether was slack and the cart was in the middle of the belt, pulling on the tether will not disturb the cart from that position but will show a force on the tether directly in response to the pull on the tether. In other words, it will act like an object anchored to the earth to a certain extent.
See a tether in the original model ? No, moot point. No feedback, but a load for the belt motor that does not exist in the current model, or in reality.
Fire fighting in an impotent attempt refute my claim. Stop trying to over-warm my ideas.
To achieve this balancing act, the wheels must slip on the treadmill surface. To move the cart forward on the belt, the wheels must slip more so that the propulsive force from the prop has less counterforce to work against. Conversely, if the wheels slip less and grip the surface better, there will be more force moving the cart with the belt than the prop can compensate for, and the cart will move back on the belt.
With the correct amount of friction, that which represents a realisitc value, the cart will go back with the belt. It does not because the friction is poorly modelled, so in concert with the badly modeled wind, the system responds by balancing instead. No choice.
So the whole premise is that the treadmill test has been cleverly set up to achieve the correct amount of slipping so that the cart can't gain KE relative to the ground in either direction, therefore it will maintain a steady state position on the treadmill for as long as the treadmill will run. This however proves nothing about actual travel along the ground because the cart has zero KE in relation to the ground, which Humber perceives as an absolute.
Cleverly? Stupidly. DO NOT SAY THIS AGAIN. I made it clear it was an illusion. If you made it, or fell for it, that is of no consequence.
Yes I do. It is absolute. It should consume power. It does not because the model is constructed by those who don't know what they are doing, so what is seen to be true, is true.
He thinks that because KE is stated as 1/2 mv2, the force required to move the cart is a function of the square of the speed change, when in actuality Newton states that F=MA, not velocity.
Not worthy of response. Derive the KE equation from first principles. Try moving from zero to v without a. It is the integral, that equation is the simplest.
He proclaims that his view reflects Newtonian physics and indisputable, when in fact it is pre-Newtonian physics, the very thing he is attributing to all others. Fortunately, the history of physics and the very laws as stated by Newton prove that wrong.
CERN makes new physics, not me!
The physics is not wrong, you are! I claim no adherence to any recondite theories. Humber physics... pathetic attempt to tarnish me.
Spork, I proposed a couple of tests based on Humber's theory of operation:
His secondary claim that the cart responds to a load as supplied by the tether can be tested as well.
Strawman. next
His tertiary claim that the cart will not change position while the treadmill is tilted can be tested at the same time.
Strawman. Next.
I hope that I've been able to clearly describe the essence of Humber's claims. With this in mind, I can think of several ways to test his theory. I'll leave that up to you and JB to devise mutually agreeable tests (again, hopefully) that you might be willing to conduct on your cart.
Make sure the wheel is in good contact with the belt. It will go backwards.
If not, then there so what. It still has no KE, and that is wrong.
One more note, maybe this quote explaining the failings of the KE view from the site that I linked earlier will help explain Humber's reluctance to go beyond the kinetic energy argument:
Reluctance to accept otherwise? The KE argument? I am trashing the whole lot!! Baby talk. New romance science.
"The ability of stress to amplify force is even more mysterious, regardless of the definition of energy. Since force is interchangeable with motion, amplifying force does not conserve energy. The force-distance analysis creates the appearance of amplified force not amplifying energy, because there is a mathematical relationship between the symbols. But the symbols (½mv² and Fs) are meaningless. Their absence of a relationship to objective reality immunizes them from contradictions with it, even with such mysterious complexities as force amplification."
Ooohh resonance is now a mystery too.
W = f xd, yes. Need more energy when F means more work.
Ha!. It's a wind cart, not a mystery.
Bad logic, bad model, faux theories, no attention to evidence, hubris, closed minds, ignorance, waffle, disrespect for others, magical forces, motion without energy velocity without time, instantaneous acceleration, model fitting, laughable hypothesis, bizarre proof by van....
