the expanding matter hypothesis

[jts]

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.

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?

[amnal]

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.

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.

[jts]

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.

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.

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).

[robinz]

@jts:

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

[HermanHiddema]

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.

Please don't.

[Violence]

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.

[phillip1882]

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.

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.

[amnal]

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.

well last i checked newton said exactly that since Force = mass*acceleration, wherever you have acceleration you must therefore have force.

Newton did say this, and it is accurate.

while in part i agree.

You don't agree with that in its entirety

i would only argue impact force = mass *acceleration.

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.

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.)

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.

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.

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.

[fwiffo]

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.

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.

[phillip1882]

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

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.

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

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

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.

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.

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.

[amnal]

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

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.

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

Extended trolling, which I nevertheless felt obliged to counter.

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

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.

(In the following, I assume that when you say 'is', you mean what I do when I say 'exerts' below).

Seriously, look up what you're talking about. You are very very wrong, and clearly have no idea of the physics behind these things.

You can't say 'gravity isn't a force because it does not have an exchange particle', because this has no bearing on what a force is. Gravity does exert a force, of magnitude GmM/r^2, and can be measured quite easily. This force causes an acceleration, exactly as basic physics predicts.

What gravity is is a separate question, and has no bearing on the fact that it exerts a force by any standard definition. It turns out that modelling it as a curvature of space-time works extremely well, though. This model has gravity exert a force...which works fine with classical mechanics.

Back on the topic of exchange particles, it isn't obvious that gravity doesn't have one. You can look up 'graviton' on wikipedia for more information, though the ideas behind this are relatively advanced quantum mechanics. On the other hand, it may not have one...this is an unsolved question in quantum mechanics.

I have no idea what you think a 'magnetron' is.

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.

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.

I...don't know how to tell you you're wrong any better than various people already have. What is observed is precisely what is predicted by standard classical mechanics.

During freefall, every part of the spring is acted upon by gravity in the same way. In the spring's reference frame, the only force upon is the internal force causing it to pull together, so it does.

It is not true that all other examples of force cause the spring to stay stretched. It is perhaps true that all the examples you have considered cause it to stay stretched (I haven't thought about it), but this would probably be because you are pulling the end of the spring rather than exerting an equal force upon every atom (as gravity does). This is a fairly fundamental difference in the mechanics.

[BaghwanB]

OK. I'm calling science troll on this discussion. Phillip1882, I'm sorry if you are actually believing this train of thought you've been describing, but as has been stated earlier, you don't really seem to even have the terminology down to try to explain/defend these theories much less a solid rebuttal for hundreds of years of classical mechanics. And if you really need to actually pull a spring across a table to see what'll happen, I'd suggest spending some more time working with thought experiments before demanding justification for how things fall. Again, sorry if these are your actual beliefs, but based on what I've seen so far if everyone is being honest I don't think any minds are going to be changed or convinced here.

On a lighter note, here is my favorite science debunking/explanation in quite a while:

00663yt1.gif (62.79 KiB) Viewed 6380 times

Copyright Darby Conley 2010

Bruce "I have a degree. In Science!" Young

[jts]

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.

Phillip -- if I tied a rope around your neck and started accelerating your body at 9.8 m/s^2, what do you think would happen?

Have you ever dived head-first off a diving board? What happened?

Do you see what I'm driving at? I think this is more evidence for our theory.

[jts]

* 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.

I like this "hydrogen bond" hypothesis, but I'm afraid that your explanation fails to account for disappearing socks. MacCutcheon's theory holds out the promise of a Grand Unified Theory of Laundry Anomalies.

[phillip1882]

seriously not trying to troll guys, I'm just trying to debate in a logical manner.

can you give me an example of a force that wouldn't cause the spring to stretch?

I'll go ahead and end my argument here, as it's clear to me at least we've hit an impasse, i won't convince you, you won't convince me, so let's just stop.