Um...no. In its steady state prior to falling, the gravitational force on the rock is balanced by the restoring force from the string. Once freefall begins, the restoring force is all that's left and the spring collapses. If you are lucky, you'll actually see the spring/rock combination oscillating.



Um...no. There are several problems here. If it doesn't deflect a compass needle then it's not magnetism--it's static electricity. Magnetic forces add as vectors; they do not need to "overcome" the earth's magnetism. Magnetic monopoles have never been observed, and if they do they would certainly affect each other; see the difference between Maxwell's equations for electricity and magnetism to see what the effect of a magnetic monopole would be.

The explanations that you have put forward tell me that you have no training in even basic physics. You seem to put an awful lot of faith in the writings of someone who essentially claims that all of modern physics is incorrect. The burden of proof for such a claim is significant and is lacking in this case. Having glanced at the first chapter of his book (posted online), it's pretty clear that this writer is a quack who is trying to earn a few bucks bamboozling the public at the bookstand.

Speaking as someone who is a professional physicist, let me tell you that the examples you have presented are readily explained by modern physics and your alternate explanations are unphysical and incorrect.

There are two forces being applied to the spring causing it to stretch. Gravity, and a force in opposition to gravity which keeps it from falling. Given that they're at opposite ends of the spring and in opposite directions, the spring stretches out. When you let go of the spring, one of the forces is removed, so the spring collapses.

You can try the same thing without involving gravity if you'd like. Lay a spring on a table and try to stretch it out by applying only a single force (i.e. tugging on one end). It won't work! The spring will slide across the table just the same as if gravity were causing it to fall. You have to pull at both ends to stretch it out. Let go with one hand, and it will spring back - and if you continue to pull with the other hand, it will resume sliding across the table at the same time.

Edit: D'oh! Ninja post.

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KGS 4 kyu - Game Archive - Keyboard Otaku

thank you! now this is the kind of thing i'm after! a reprocable experiment worth trying. i would very much like to try this to see if the spring does indeed collapse during the release.
i have my doubts, i honestly don't know one way or the other. if it does then i'll drop this post if it doesn't then i'll persist.

here's a bit further as to why i'm unsure.
suppose instead of pulling only one end of the spring at the rate of g, you swung it around yourself at the rate of g.
i'm confident, though not certain that the spring wouldn't just follow my motion but also stretch out.
but i agree that if you pull on a spring, the spring should follow the line of motion. (ie. if you pull on it at the rate of g along a straight line, will it stretch? hard for me to say, one way or the other.)

All these fun forces there are for you to read up on

I've always been troubled by general relativity because - while Einstein's curved space-time is clearly an improvement over the flawed Euclidean/Newtonian paradigm - it still cannot explain anomalies in spacetime at the mundane scales where relativity (falsely) predicts that space will conform to Euclidean "laws".



Can McCutcheon explain this well-known "triangle paradox"? I think that would definitely prove that his theory has more explanatory power than Einstein's.


Also, is it possible that, because washer-dryers are magnetic monopoles, they cause matter to expand at less than its normal rate? My sweatshirts normally don't fit quite so well after I've put them through the wash.

Well... you know... you could also just... draw a free body diagram... like any fledgling physics student.

When you hold the spring + ball system after the spring has stretched, the forces are as follows

Force of the hand exerting on the system = mg + kx, where m is the mass of the system, g is the gravitational accel, k is the spring constant, and x is the distance the spring has been stretched.
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Hand holding spring.
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| Force of the system = mg + kx
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O

Let's look what happens when we take away the hand.

Force of one end of the spring = kx
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| Force of one end of the spring = kx
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O

Because gravity affects the entire system equally, no net force is felt by any part of the system with respect to any other part of the system.

However, the force of the spring, given by kx, is no longer balanced by the hand, and as a result, both ends of the spring feel the kx force to return to its original, unstretched state. Perfectly normal behavior.

To further illustrate why this line of thought is false, let's simply turn the system upside down.

First, we assume that our spring has a relatively low mass and a high k, meaning, if we just hold the spring, it will not stretch significantly. It requires the mass of the ball to stretch. We perform the first experiment with easy success, and observe oscillation.

Now, we turn the entire setup upside down.


Force of the hand exerting on the system = mg.
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Hand holding ball with spring attached.
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kx is so small here, it is negligible.

We let go. There is no oscillation in mid air, and there is no net difference of force felt within the system as it falls.

First scenario: kx internal force was large and significant. We observed oscillation in midair.
Second scenario: kx internal force was small and insignificant. We observed no significant oscillation in midair.

Therefore, the spring's internal force was the cause of the midair oscillation observed in our system.

It's been a while since I've taken physics, I suspect that I put the kx force in the wrong places, but I'm quite sure about where the forces are once the hand lets go of the system.

Everyone knows the triangle thing is nonsense...but I think you're on to something with the washer-dryer thing

@jts:

What does your "triangle paradox" (which I've seen before, and have attached a hint to the explanation below) have to do with general relativity, or indeed physics in general? It's a purely abstract construction - and basically an optical illusion, at that. No physical theories are required.

(It's possible you're joking, in which case I apologise, but if so it probably won't be obvious to everyone.)

Hint to the solution of the "paradox":

violence, an excellent post, but agian i'd like to point out if you rotate a spring such that it's changing direction at the rate of g it streches out. if you let a spring hang freely even without wieght it streches. if you pull it at the rate of g along a striaght line i suspect though am in no way confident that it will stretch. therefore assuming these experiments are true, it should stay stretched during free fall, assuming gravity is a force. yet it doesn't, it collapses.

How are you imagining pulling it? Were you going to pull it just from one end, or were you planning on dividing the force of your pull across every atom of the spring?

By 'pull at the rate of g', I assume you mean pull with the same force as gravity. Your posts indicate some confusion between forces, accelerations and velocities.

If you pull even one end of the spring with a constant force, you will certainly observe it to stretch. If you hold one end and do the same, you will see it stretch.

As has been pointed out, to actually have the same effect as gravity, you need to pull on every atom simultaneously in the same way. I've lost track of your individual little thought experiments, but this would be a vital difference for some of them.

But maybe this is part of MacCutcheon's theory of gravity. I've attached an illustration (since Violence provided some free-body diagrams, I think it's only fair and balanced to illustrate the opposing view, as well).

@jts:

I definitely apologise for my previous post now - this is one of the best displays of "counter-trolling" I have ever seen

Please don't.

Philip, I'm beginning to suspect that you haven't read my post at all, or you're just trying to troll me.

Force means movement(usually). There cannot be a change in movement without a force causing it.

If you observe no special movement in a string tied to a rock falling to the ground, yet you observe that there is movement in a spring tied to a rock falling to the ground, the first thing you think of is NOT "oh, this defies gravity!"

It is instead "I wonder what force causes that to happen?"

In any of your examples, replace your spring with a string and see if you can find some kind of movement that opposes gravity. Why is it that all of your example include springs?

Because the spring's internal spring force is the source of the opposing force that makes you think that it is defying gravity.

well last i checked newton said exactly that since Force = mass*acceleration, wherever you have acceleration you must therefore have force. while in part i agree. i would only argue impact force = mass *acceleration. that is there must be a direct link between the object and the force. (in the case of magnetism scientists have indeed detected magnetic particles.)

again, in the case of hanging a spring even without weight, it stretches in the direction of gravity. but when you let go it collapses. in one scenario, it acts like a force, that is when it has a direct link to the object. but in free fall, when its is no longer linked to the earth, it acts precisely as it would in a zero gravity environment, in terms of oscillation. acceleration without force. i can give other examples if you don't like this one.

Newton did say this, and it is accurate.



You don't agree with that in its entirety



Well, I'm not sure what you mean by this, but I'll go so far as telling you that you're wrong anyway. Unless you can present evidence to the contrary, which you can't.

Seriously, we've been doing classical mechanics for a looong time. We know where it's right, especially in trivial situations.



I have no idea what you're talking about. What do you mean by 'direct link'?

And magnetic effects are well known properties of some particles, but this has no bearing on anything else you've said.



I still don't know what you mean by 'linked', but none of these situations are remotely surprising. Have you even been taught any classical mechanics? This is trivial stuff, such as you would find in an introductory textbook.

There is no acceleration without force. Not ever. It's simply impossible. Acceleration = force/mass, so if there's an acceleration, working out what the force is is easy. Can you give a coherent explanation of a situation where you think there is such an effect?

If you are saying that oscillation is acceleration without force (though I'm not sure what you mean by 'oscillation', in context), you are again wrong.

Yes, if you hold a spring at one end, letting the other end dangle, it will stretch out some (assuming it's not too stiff). The reason is that the spring itself has mass. So the lower part of the spring is being pulled by gravity, which stretches the upper part of the spring. If the spring is long and stretchy enough, you can observe that the top part of the spring is more stretched than the lower part because more of the spring's weight is below that part.

Again, the reason it stretches is because there are two forces acting on it, gravity, pulling it toward the Earth, and your hand, countering gravity and keeping it from falling. If you drop it, it will collapse back to its relaxed state because you've removed one of the forces holding it in the stretched position.*

This is also why the spring will stretch if you yank on it (two forces - your hand and the spring's inertia) or swing it around in a circle (your hand on one end and the centrifugal force on the other; the spring's inertia trying to go in a straight line while you force it into a a circle).

As others have pointed out, this is all elementary middle/high-school level physics. Regular old Newtonian mechanics predicts that falling objects will more-or-less behave as if they were in a gravity-free environment.

* This is what is causing jts's sweatshirts to shrink. The springy fibers of the cloth are stretched over a loom during manufacture, and they get stuck in that position because of hydrogen bonds between the fibers. The washer/dryer has enough energy to break those bonds allowing the fibers to return to their relaxed, shorter state.

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KGS 4 kyu - Game Archive - Keyboard Otaku

okay let me try this one last time since there seems to be some confusion about what I'm saying.

what do you think I've been trying to do?


i mean there must be some stream of particles, (either photons, or magnetrons, electrons, atoms etc.)
that connects the two systems.
gravity seems to be the only exception to this rule which is another reason i suspect it isn't a force.

no, I'm saying the downward fall occurs without force, because if there were force, then the spring would not oscillate during free fall, since all other examples of force cause it to stay stretched.