good old-fashioned swinging weight experiment

[F.Nepure]

Dear all,
Here is a description of a practical experiment which i amused myself with recently, which is not in french, and does not involve gravitons or dark matter (as far as i am aware)

Firstly, here is the experimental aparatus:-
(which is definitely a layman's experiment, and is not based on calculated mathematical theory)

The experiment was to measure the radial forces experienced by a single weight travelling at 0-50rpm.
I was most interested in the outward radial forces from 90 - 270 degrees rotation, and the lack of inward/outward forces from 270 through to 90 degrees rotation at certain speeds.
(Basically to examine forces acting inwards/outwards at 90 degrees to the axis)

I set up a swinging weight on a long 1" kart axle on a pair of roller bearings.
The single weight, weighing 600g, is fixed to a sliding rail, so it can slide radially in and out on a rod.
The weight is connected to the non-sliding bit by an elastic cord.
The elastic can then be adjusted in strength by adding or subtracting rubber bands.
The sliding rail has a stop on it at 50cm, so normally the elastic holds the weight against this stop, and prevents the weight flying off the end at speed.
So at low speeds, the weight simply describes a 50cm radius circle.
A big cranked handle was fitted at the far end of the axle so that an enthusiastic helper could crank the assembly round by hand at the required speed.
He had a musician's metronome set to the required speed to give him a visual aid for how fast he should crank his handle.
The electronic metronome flashes LED's at the required speed (Beats per minute for the DJ's)

The idea of this little apparatus being to give a workeable demonstration of the radial forces moving a weight in and out at certain speeds.

The strength of the elastic was adjusted so that at roughly 30 rpm, the weight starts to stretch the elastic.
This happens from 90 to 270 degrees rotation.
So the weight is then coming off it's stop at around 90-100 degrees and sliding out radially, stretching the elastic as it does so,
This reaches a maximum at 180 degrees, and then it comes back in from 180-270 degrees, and can be heard clonking, as it returns to it's stop at around 270-280 degrees.

Because everything becomes a blur at 50rpm (unless you have very quick-moving eyeballs) something was needed to check the weight's radial movement at 180 degrees.
A stroboscope, (as used for checking car ignition systems) was used to 'freeze' the weight's position at 180 degrees.
A small switch operated by a plastic cam was fixed at the far end of the axle to give a trigger signal for the stroboscope at 180 degrees.
White lines every 1cm were painted on the weight's slider to give a visual indication of how far the weight had moved.

And so at 50 rpm, i could observe that the weight was moving out 3cm at 180degrees.

At speeds over 70 rpm, the lack of adequate centripetal force provided by the elastic means that the weight stays off it's stop for longer and longer duration,
until at 90 rpm, it is continuously stretching the elastic for the full 360 degrees.
(and you start to worry that if the elastic snaps you will have a big hole in the roof of your shed!)

To verify the force in the elastic i did a static test, hanging weights on the elastic.
And it required a force of 30 Newtons to stretch it the 3cm that i observed with the stroboscope at 50 rpm.

The other point i noted was how the weight's angular velocity momentarily becomes equal to gravitational forces (at a certain speed) from 270 to 90 degrees.
With the elastic removed, the weight was given a 2nd stop to then allow it to travel only 5mm back an forth on it's sliding rail.
At low speeds, the weight can be heard clonking as it moves out at 90 degrees, and comes back in at 270 degrees.
Than after a certain speed, it is glued to the outwards stop by it's angular velocity.
It follows that at a certain speed, there is a concise balance between a weight's angular velocity (forcing it outwards) and the universal gravitational force holding it downwards.
This only occuring on the top side of the wheel, from around 290 to 70 degrees.

All pretty basic stuff, but it was great for the kids (and me), who now know a bit more about centripetal force & angular velocity.

Obviously, a single swinging weight is far different to a pair of weights at 180 degrees to each other, or many weights positioned around a wheel.
The single weight accelerates unhindered from 0 to 180 degrees, and then slows again on the up-side.
Which made me think of the feeling of going too high on a children's swing in the playground (as all big kids do).
By moving your bodyweight you can increase the accelaration as you swing downwards, enabling you to go higher and higher until you get scared.
If the swing had a fixed pair of arms (instead of ropes) you could keep going higher until you could do the full 360 degrees.
I like the idea of this - as you would then have a personal experience of the forces involved in flying around in a circle. Perhaps i should build this as my next project.

Anyway - back to the experiment, my speculation is whether or not the 30N force applied to the elastic can be harvested or utilised in some way.
Or in other words, is this radial force greater than the decrease in speed caused by the weight having moved outwards by 3cm?
And if so could this energy in the elastic be re-applied to accelerate the wheel sometime after 270 degrees? (when there is no radial force on the weight here at certain speeds)
I'm sure that those of you with greater mathematical ability than myself will have an answer to this.

I often wonder whether Bessler was much of a mathematician, as Newton's laws were probably not in common usage in his part of Germany in 1711.
If he did do any maths, what equations did he use i wonder?
As Newton's laws seem to outlaw the possibility of generating rotational power from gravity, it seems to me as though it would be pointless to use them to verify any potential design.
But at the same time one cannot ignore that they are valid for what we all observe (it seems).
i.e. no matter how weight/s are arranged or moved on a wheel, it will always require the same amount of energy to raise it as it generates falling (minus frictional losses).
The fundamental concept behind Bessler's wheel (assuming he wasn't a lying swindler) is that it must contradict some of Newton's observations.

Tidal power is ultimately derriving it's energy from the moon's orbit around the earth.
Is this power from gravity? What is causing the moon to rotate, and to be able to exert this power to move the oceans?

As my understanding allows: For the moon and the earth to maintain their joint orbit, there must be a concise balance between forces.
A balance between the moon's outward force caused by it's angular velocity and an equal opposite force provided by the earth's angular velocity [as Newton observed].

Gravitational effect is the invisible cord that connects the two bodies. If the earth were not providing an equal opposite force then the moon would pull the earth out of it's solar orbit.

This is one of those envisagements that is difficult for a non-scientist like myself to discern mentally, as it is not a situation that ever occurs here on the earth.
Our man-made rotating systems all have fixed centres which are completely different to the balanced centre that is created in a solar system.
The sun, earth, and moon are not fixed to anything, and so must provide opposing forces to maintain their positions.

And so it seems odd to my mind that we use the same equations (concerning centripetal force & angular velocity) to describe a solar system as we use to describe a system with a fixed centre (like a wheel).

As an example of the possible differences (as i see them) between a planetary system, and a wheel (here on earth) with a fixed centre bearing:-
I imagine a tug of war. Each team is straining against the other with an equal amount of force. And so they remain stationary.
Now imagine these two tug-of-war teams rotating around each other in space, and that gives me a mental picture of the forces in a planetary system.
Are two equal opposite forces that balance against each other like this the same as a force applied to a fixed centre?
If a centre is well & truly fixed, one can apply a massive amount of radial force to it, and yet it remains, nothing is altered, like pushing on a wall.
Whereas in a solar system, a slight difference between the two opposing foces will upset the equilibrium, possibly allowing the heavenly bodies in question to fly off into outer space.

Another small experiment which may (or may not) illustrate what i'm flatulating about is to take a stick or metal rod and fix it with a pivot to a handle at right-angles.
You can now hold the handle part, and use the force in your arm to whirl the bar around, rather like whirling a set of boleras, or in whirling a small child around in a circle until their feet come off the ground.
Exactly what angular forces are used to create these motions? Motions created by applying an angular force to a central pivot point.
This is a force system that is rarely analysed mathematically, as it does not have a fixed centre, the centre point is created by a balance between forces.
If you practice with such a swinging-stick/rod arrangement, it is possible to accelerate the bar whilst maintaining a relatively steady imaginery centre point.
There is something uncanny about this subject area of 'centres created by balanced opposing forces' which makes me think that it may have something to do with Bessler's wheel.

I'd be specifically interested to hear from anyone who has come to similar conclusions over the possible differences between centripetal forces in a solar system, and those in a wheel with a fixed centre.
Or anyone who agrees that it seems odd that we use similar equations for both.

Apologies for the length of this post, but once i start writing, i often get carried away!
Regards to all,


F. Nepure

[Gregory]

Hi F.Nepure!

Good post & thoughts on your part...
I am tired to respond to everything, but more members will come to do, I think.

Or in other words, is this radial force greater than the decrease in speed caused by the weight having moved outwards by 3cm?

Unfortunately, as far as I know it is always smaller or equal, minus the friction and losses. This is not the right way... Do the same without changing the moment of inertia of the system. So, one weight goes out while another goes in an equal distance, or something.

Tidal power is ultimately derriving it's energy from the moon's orbit around the earth.
Is this power from gravity? What is causing the moon to rotate, and to be able to exert this power to move the oceans?

Actually it is the formation of the solar system (after the formation of the galaxy, after the big bang...) which is causing the moon to rotate.
The moon only obeys to Newton's laws:
After sent in motion, it continues this motion as long as an external force does not change this. (there is virtually no friction in space)

Gravity and inertia were (and are) neccessary components of the process, but they are not provide any energy for the moon's rotation (except maybe at startup, pulling the pieces of mass together & continue motion), they're just maintaining an equilibrium. If we would place a big load on the solar system, it would slows down and finally collapses due to gravitational forces. (It's a complicated version of a very big flywheel)


Great thinking otherwise, thx!

[F.Nepure]

Having just read Victus Mortuum and Mr.Umez posts on the calculations involved with CF, i now understand a bit more about the observations i made on my model. I was especially interested by Ovyyus' idea of attempting to store CF in a spring.

In the past i've built 2 machines based around the idea of storing CF in elastic/springs, one with 2 weights at 180 degrees, and another with 3 weights at 120 degree intervals.
But the problem with both of these designs was A) that they didn't work and B) that they didn't work......

The weights worked on sliding rails as described in the post above, but were attached to skate wheels. These skate wheel then flew around a large rim which was arranged so that force in the elastic was held from 200 degrees onwards, and then the rim curved in from 290 to 360 degrees, allowing the elastic to release it's force over this section. Friction loss through the skate wheels was always quite high.
As it remained stubornly immobile, i then dismantled it & set up the experiment (described in the post) to more carefully examine exactly what the elastic was doing and when, and at what speed.
As my maths is no good, i needed a visual idea of what the angular velocity was doing to the elastic.

But i may well have a go with another 2 weight design that attempts to move a weight out at 0 degrees to counteract it's pair putting CF into elastic at 180 degrees.

Axel made an observation that CF could not be Bessler's motive power because it does not have initial torque.
My take on this is that if sufficient energy from CF is stored in elastic/spring or other medium, then a large chunk of it will still be stored when the wheel is stationary.
If this stored energy then acts on a stationary rim or through globes sitting on varying width rails (as shown in MT124) then the machine might then be capable of accelerating from a standstill.

Thanks for the observations on the tidal energy & the solar system's flywheel effect, which explains a lot. I'm slowly beginning to grasp some ideas on energy & force that have long eluded me, but i still need to brush up on my maths.

I can post a pic of the machine mentioned above (the one with 2 weights & skate wheels acting on a fixed rim) if anyone is interested in a non-working machine.

[evgwheel]

F.Nepure

Quote:
Firstly, here is the experimental apparatus:- (which is definitely a layman's experiment, and is not based on calculated mathematical theory) Unquote.

Thank God for that, I like the way you think and seek answers in the way it should be done (in my opinion).

Keep on doing what you are doing and foremost keep on learning from physical experiments.

When you are lucky enough to stumble on the answer (and your thought process may just do that) then it is time to work out the formulas and be a learned person in the society.

Best post I read for months.

[daxwc]

Gregory said:

Actually it is the formation of the solar system (after the formation of the galaxy, after the big bang...) which is causing the moon to rotate.
The moon only obeys to Newton's laws:
After sent in motion, it continues this motion as long as an external force does not change this. (there is virtually no friction in space)

That doesn't answer the question where the tidal power comes from if it is not from rotational momentum and gravity. I brought this up on another forum only to be taunted, but their answer didn't satisfy me neither. Far as I am concerned the Emperor has no clothes and if energy is ever drawn out of gravity it will be at 90 degrees.

Maybe one day hopefully in the future humans will be laughing at mankind of our time and why they were so blind to a force all around them... but then again, if it were not for cranks the earth would still be flat. If everybody thought the same we would still be throwing rocks at each other. ;)))) Nothing wrong with a good rock fight!

[jim_mich]

F.Nepure, you have re-invented the speed indicator from the old hand crank cream separator machines. They had a weight in the center of a bell that could swing in and out thus hitting the bell twice, once, or none each rotation. One ding per rotation was the correct speed for the machine.

Or in other words, is this radial force greater than the decrease in speed caused by the weight having moved outwards by 3cm?

Unfortunately, as far as I know it is always smaller or equal, minus the friction and losses. This is not the right way... Do the same without changing the moment of inertia of the system. So, one weight goes out while another goes in an equal distance, or something.

I agree. Bessler says that one weight moves out and one weight moves in. The inner weight with less CF must pull the outer weight with greater CF back toward the center. At first look this may sound impossible, but once the secret is known it is very easy.

When two weights exchange places with one moving inward and the other moving outward then the combined act of moving inward and outward has little affect on the wheel's speed. The inward moving weight causes the wheel to speed up and the outward moving weight slows the wheel down about the same amount. The weights exchange places on the wheel and conservation of energy is maintained.