Angular momentum conservation is a false concept (in the lab or ice rink). It may be the key concept that keeps people from developing wheels. The ice skater is impressive alright but it is not a legitimate physics experiment. If the masses move in and out while conserving mrr then all of Newtonian physics falls into shambles. If F = ma is false then prove it with a real physics experiment not with an ice skater.
I just put together a new cylinder and spheres because it has a nice verification of this exact problem.
The cylinder is a 3 inch PVC pipe coupler with two one inch hole through a diameter; that is, holes at 180° around the circle. Each hole seats a one inch sphere. That makes the cylinder and spheres balanced. This is a wheel; with two spheres across a circle.
I ran a string, or line, from one sphere (that is seated in one hole) around almost half the circumference of the coupler to the other hole on the other side. From there the line goes inside across the circle of the coupler back to the first hole. From there the line loops around the circumference of the coupler to be attached to the other sphere that is seated in the other hole. This makes a line (with the spheres) about 15.25 inches long, that has two one inch sphere attached to each end; with a PVC pipe coupler centered in between them.
You can place a three inch pipe in the coupler to increase the mass. You can seat the spheres and spin the system (pipe, coupler and spheres) . After release: the sphere will quickly stop the cylinder and the spheres will then have all the motion. The coupler has a diameter just under 4 inches; 3.94. The pipe has a smaller radius; but I will make my point with 3.94.
The mass of the cylinder for a good stop is about 1300 grams and the spheres have a mass of 132 grams. This is a mass difference of about 11
If angular momentum is conserved the spheres would only need to be moving at about the same rotational velocity. Because 3.9² is 15 and the radius difference is 15.25 / 3.94 = 3.9: 132 g x omega x 3.9 x 3.9 = 2000 which is greater than the original angular momentum of 1,432g x omega x 1 x 1.
If the rotational speed of the spheres is not increased then how can the spheres absorb motion from the cylinder when they are moving together at the same speed?
If Newton's momentum (F = ma) is conserved the spheres will have to be moving 11 times faster. The spheres have a 3.9 radius increase so they are already moving 3.9 faster at the same rotational speed. That means that the rotational speed will have to pick up by 2.8 in order to conserve linear Newtonian momentum (F = ma). The momentum lost by the cylinder has to be given to the spheres.
Now the absorption of motion from the cylinder can be explained. The spheres jump out ahead of the cylinder and begin trying to force it to come along. All that does is make the cylinder go slower yet; and the tug of war begins.
So what does the observer see? He does not see a docile set of spheres lollygagging out at the same rotational velocity; he sees the second scenario; a violent exchange of motion. And the spheres rotate much faster.
Again I ask for no comments; because I know what I am doing. I do these experiments; and the vile comments are not appreciated.
If you want to build your own cylinder and spheres I will help; but I disdain this ugly bantering. The ice skater is conserving linear Newtonian momentum.
energy producing experiments
Moderator: scott
re: energy producing experiments
Ice skaters are a good example of momentum conservation. When they move from a 20 meter circle to a 5 meter circle real momentum is conserved. We all know that linear motion is conserved when they move from a 20 meter circle to a 5 meter circle. They use their muscles to change the angle of the skate and then lean into the new circle; and no one contends that angular momentum is conserved. No one contends that angular momentum is conserved because it obviously is not. If the skater is moving 3 m/sec in a 1.7 meter circle she is still moving 3 meters per second when she changes her path to a 17 meter circle.
It is only when the mass distribution is difficult to determine do people begin to contend that angular momentum conservation occurs.
Most of this confusion is willful; people will say that the 20 meter to 5 m circles is different than the spin. Really; why? Obviously it is not different; it is the same; muscles reducing the radius of the circle.
What is different is that the mass distribution in the 20 and 5 meter circle can be measures; the total mass of the skater is roughly a point mass at 10 m and 2.5 m: the mass distribution about the twirl or spin has thousands of radii.Â
Note that the winner is tall and she stretcher herself into a straight configuration; I am guessing that the radii are smaller than people think. Also the human eye can no longer pick up the motion; which is what makes the move so impressive.
For the skater posted by Jim
https://www.youtube.com/watch?v=AQLtcEAG9v0
: she starts in a 20 meter circle and then goes into a twirl; Okay lets do the math.
I made my best guess at what these numbers should be; I did not work backwards.
For the 20 meter circle: Arc velocity = 4 m/sec, R = 10 m, omega = .4 radians per second; mass = 60 kilograms:Â
Angular momentum for the 20 m circle is;Â 60 x .4 x 10 x 10 = 2400
For the twirl:  Arc velocity = 4 m/sec, R = .13 m,  omega = 30.8 radians per second; mass = 60 kilograms:
Â
Angular momentum for the twirl is: 60 x 30.8 x .13 x .13 = 31.2
So where is the angular momentum conservation; does 2400 equal 31.2?
For angular momentum to be conserved the rotational speed for the twirl would have to be 2366.9 radians per second: x .13 for 307.7 m/sec : /.8168 m/rotation for 376.59 rotations per second: x 60 sec/min for 22,595 RPM.
For Newtonian momentum conservation the rotational speed would be 30.8 radian per second; which is 4.90 RPS; or 294 RPM. What RPM did they mention? 308??
Haley’s comet has the same angular momentum no matter what the radius; angular momentum must be applicable at all radii. Then why does the 10 m radius to .13 m radius not work?
Because where angular momentum conservation was discovered to apply was under conditions of gravitational acceleration between the near circle and the far circle. Orbits. The skater is not in orbit.
It is only when the mass distribution is difficult to determine do people begin to contend that angular momentum conservation occurs.
Most of this confusion is willful; people will say that the 20 meter to 5 m circles is different than the spin. Really; why? Obviously it is not different; it is the same; muscles reducing the radius of the circle.
What is different is that the mass distribution in the 20 and 5 meter circle can be measures; the total mass of the skater is roughly a point mass at 10 m and 2.5 m: the mass distribution about the twirl or spin has thousands of radii.Â
Note that the winner is tall and she stretcher herself into a straight configuration; I am guessing that the radii are smaller than people think. Also the human eye can no longer pick up the motion; which is what makes the move so impressive.
For the skater posted by Jim
https://www.youtube.com/watch?v=AQLtcEAG9v0
: she starts in a 20 meter circle and then goes into a twirl; Okay lets do the math.
I made my best guess at what these numbers should be; I did not work backwards.
For the 20 meter circle: Arc velocity = 4 m/sec, R = 10 m, omega = .4 radians per second; mass = 60 kilograms:Â
Angular momentum for the 20 m circle is;Â 60 x .4 x 10 x 10 = 2400
For the twirl:  Arc velocity = 4 m/sec, R = .13 m,  omega = 30.8 radians per second; mass = 60 kilograms:
Â
Angular momentum for the twirl is: 60 x 30.8 x .13 x .13 = 31.2
So where is the angular momentum conservation; does 2400 equal 31.2?
For angular momentum to be conserved the rotational speed for the twirl would have to be 2366.9 radians per second: x .13 for 307.7 m/sec : /.8168 m/rotation for 376.59 rotations per second: x 60 sec/min for 22,595 RPM.
For Newtonian momentum conservation the rotational speed would be 30.8 radian per second; which is 4.90 RPS; or 294 RPM. What RPM did they mention? 308??
Haley’s comet has the same angular momentum no matter what the radius; angular momentum must be applicable at all radii. Then why does the 10 m radius to .13 m radius not work?
Because where angular momentum conservation was discovered to apply was under conditions of gravitational acceleration between the near circle and the far circle. Orbits. The skater is not in orbit.
Re: re: energy producing experiments
I beg to differ.pequaide wrote:Angular momentum conservation is a false concept (in the lab or ice rink). It may be the key concept that keeps people from developing wheels. ...
A failure to appreciate the nature of Jerk is the reason that keeps people from harnessing gravity.
I'm sure RAR don't appreciate it either but they have stumbled on a way they can transmit jerk energy from the angular momentum transmitter to the angular momentum receiver without it showing up in the second derivative books.
A bit like a successful embezzler - or banker, the most successful of all embezzlers.
Who is she that cometh forth as the morning rising, fair as the moon, bright as the sun, terribilis ut castrorum acies ordinata?
re: energy producing experiments
RAR is like a successful embolism.
re: energy producing experiments
Yes, and I'm the only one ever to make "feeble" jokes.
Explain to me why, especially after all this time, RAR deserves your unconditional loyalty?
Explain to me why, especially after all this time, RAR deserves your unconditional loyalty?
re: energy producing experiments
Ok. Well, there ya go. ;-)
re: energy producing experiments
You could have a immovable pin in the center of the ice rink.
From this pin you could rotate a thick upright metal bar across the ice on the end of a 10 meter cord. You could set the 60 kilogram bar moving at 4 m/sec.
You could place a second immovable pin at 4.935 meters from the first pin.
The cord would come in contact with the second pin and the bar would enter a smaller circle and head back toward the first pin.
The cord would come in contact with the first pin and the bar would be rotating at a distance of .13 meters from the pin.
I trust you all know what would happen. The bar would continue at 4 m/sec throughout the entire experiment. The bar would move around the arc of the different circles at 4 m/sec.
The angular velocity of the first, second and third circle would be: .4 radians / sec; .7897 radians /sec; and 30.769 radians / sec.
The angular momentum of the first, second and third circle would be: 60 kg x .4 x 10 x 10 = 2400; 60 x .7897 x 5.065 x 5.065 = 1215.55: and 60 x 30.769 x .13 x .13 = 31.2.
The arc velocity of the first, second and third circle would be: 4 m/sec; 4 m/sec and 4 m/sec.
The Newtonian momentum of the first, second and third circle would be: 60 kg x 4 m/sec = 240 ; 60 kg x 4 m/sec = 240; and 60 kg x 4 m/sec = 240.
In none of the circles is angular momentum conserved.
In all of the circles linear Newtonian momentum is conserved.
This experiment can be and is done with pucks on an air table; I have done it myself ; and the results presented are correct. Angular momentum is never conserved and linear momentum is always conserved.
The anecdotal spin of an ice skater conserving something other than linear Newtonian momentum is an example of a very vivid imagination; and a complete misunderstanding of the work of Kepler. Kepler was talking about planets and comets not ice skaters.
From this pin you could rotate a thick upright metal bar across the ice on the end of a 10 meter cord. You could set the 60 kilogram bar moving at 4 m/sec.
You could place a second immovable pin at 4.935 meters from the first pin.
The cord would come in contact with the second pin and the bar would enter a smaller circle and head back toward the first pin.
The cord would come in contact with the first pin and the bar would be rotating at a distance of .13 meters from the pin.
I trust you all know what would happen. The bar would continue at 4 m/sec throughout the entire experiment. The bar would move around the arc of the different circles at 4 m/sec.
The angular velocity of the first, second and third circle would be: .4 radians / sec; .7897 radians /sec; and 30.769 radians / sec.
The angular momentum of the first, second and third circle would be: 60 kg x .4 x 10 x 10 = 2400; 60 x .7897 x 5.065 x 5.065 = 1215.55: and 60 x 30.769 x .13 x .13 = 31.2.
The arc velocity of the first, second and third circle would be: 4 m/sec; 4 m/sec and 4 m/sec.
The Newtonian momentum of the first, second and third circle would be: 60 kg x 4 m/sec = 240 ; 60 kg x 4 m/sec = 240; and 60 kg x 4 m/sec = 240.
In none of the circles is angular momentum conserved.
In all of the circles linear Newtonian momentum is conserved.
This experiment can be and is done with pucks on an air table; I have done it myself ; and the results presented are correct. Angular momentum is never conserved and linear momentum is always conserved.
The anecdotal spin of an ice skater conserving something other than linear Newtonian momentum is an example of a very vivid imagination; and a complete misunderstanding of the work of Kepler. Kepler was talking about planets and comets not ice skaters.
re: energy producing experiments
In the new or current cylinder and spheres the mass ratio is about 12.4 to 1. The 1 is 132 grams for the spheres in the open rotation and 1637 grams for the closed cylinder and spheres.
So for the kinetic energy to be conserved, when the spheres are extended, the open velocity would have to be the square root of 12.4 or 3.52 m/sec . But the ratio of radius change is 15.5 in. / 3.5 in. or 4.43. So if the system maintained the same rotational velocity; the linear velocity would be too great for the kinetic energy to remain the same. The rotational velocity must slow down by 4.43-3.52/4.42 = 20% for kinetic energy to remain the same.
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Experimental evidence shows that the rotation rate of the spheres increases; when open; which is consistent with Newtonian momentum conservation.This observed rate is not consistent with energy conservation.
It is known that Newtonian momentum is conserved when a small object like the spheres gives its motion to a larger object such as the cylinder; in fact linear Newtonian momentum is the only thing conserved.
If kinetic energy is conserved when the spheres are in the open position then allegedly 75% of this linear Newtonian motion is gone. How can the only motion that restores the cylinder and spheres to their original motion be gone. If this momentum is 75% gone then the cylinder will not be restored to its original motion. Newtonian Physics requires that the open spheres have a velocity increase to about 12.4 times as fast; The velocity increase is proportional to the mass decrease.
Experimental evidence shows that after the stop; the final rotation rate of the cylinder and spheres is restored to its original rate of rotation.
The cylinder and spheres is similar to the double pendulum but it has a more massive center that gives its motion to a lighter device that is connected to the circumference of the inner circle (cylinder). The two arms of the double pendulum are probably similar to each other in mass and size. To make a double pendulum work you have to separate the lower arm from the upper arm when the upper arm is at rest and in the 6 o’clock position. Any position other than 6 o’clock the upper pendulum would have stored gravitational potential energy. The current cylinder and spheres has no gravitational potential energy because it is balanced; and it is being floated. In relationship to each other all parts are floating. It is dropping in free fall.
I think the double pendulum has a very good chance of working; as is the cylinder and spheres. But the builder must understand that he is looking for a system that concentrates the arc (linear) momentum into a small object and then throws the object. This separation or throw does not allow the motion to return to the larger object.
So for the kinetic energy to be conserved, when the spheres are extended, the open velocity would have to be the square root of 12.4 or 3.52 m/sec . But the ratio of radius change is 15.5 in. / 3.5 in. or 4.43. So if the system maintained the same rotational velocity; the linear velocity would be too great for the kinetic energy to remain the same. The rotational velocity must slow down by 4.43-3.52/4.42 = 20% for kinetic energy to remain the same.
Â
Experimental evidence shows that the rotation rate of the spheres increases; when open; which is consistent with Newtonian momentum conservation.This observed rate is not consistent with energy conservation.
It is known that Newtonian momentum is conserved when a small object like the spheres gives its motion to a larger object such as the cylinder; in fact linear Newtonian momentum is the only thing conserved.
If kinetic energy is conserved when the spheres are in the open position then allegedly 75% of this linear Newtonian motion is gone. How can the only motion that restores the cylinder and spheres to their original motion be gone. If this momentum is 75% gone then the cylinder will not be restored to its original motion. Newtonian Physics requires that the open spheres have a velocity increase to about 12.4 times as fast; The velocity increase is proportional to the mass decrease.
Experimental evidence shows that after the stop; the final rotation rate of the cylinder and spheres is restored to its original rate of rotation.
The cylinder and spheres is similar to the double pendulum but it has a more massive center that gives its motion to a lighter device that is connected to the circumference of the inner circle (cylinder). The two arms of the double pendulum are probably similar to each other in mass and size. To make a double pendulum work you have to separate the lower arm from the upper arm when the upper arm is at rest and in the 6 o’clock position. Any position other than 6 o’clock the upper pendulum would have stored gravitational potential energy. The current cylinder and spheres has no gravitational potential energy because it is balanced; and it is being floated. In relationship to each other all parts are floating. It is dropping in free fall.
I think the double pendulum has a very good chance of working; as is the cylinder and spheres. But the builder must understand that he is looking for a system that concentrates the arc (linear) momentum into a small object and then throws the object. This separation or throw does not allow the motion to return to the larger object.
re: energy producing experiments
The newest cylinder and spheres has a mass ration of about 14 (cylinder and spheres) to one (spheres). I tied the tethers to the near edges of the seat openings so there is no longer a delay for the motion of the spheres to be returned to the stopped cylinder.
The video tapes show a spinning cylinder and spheres prior to release. It shows a stopping cylinder as the spheres swing out on the end of the tether. And then it shows the cylinder being returned to its original rate of spin as the spheres swing past 90°, to tangent, and back into the cylinder.
What it shows is consistent with Newtonian arc (or linear) momentum conservation.
It shows that energy is not a conserved quantity; because the experiment does not show a 75% decrease in the spinning motion of the cylinder; because it is experimentally known that a small object cannot give its motion energy to a large object. A small object can only give its linear momentum to a larger object; this is from thousands of experiments with no exceptions.
Now it is experimentally known that when a large object gives its motion to a smaller object energy is not conserved.
The spheres appear to obtain the same speed as the cylinder's surface and seem to fly in formation with the surface of the cylinder as they come back to it. I know with shorter tethers the spheres strike the cylinder violently; so this was an interesting twist. Of course there were only a few frames of the spheres flying in formation so they may be still moving toward the surface. Not that there is any significance to this; but it is curious.
These machines conserve linear Newtonian momentum under a variety of circumstances (all circumstances no doubt).
The video tapes show a spinning cylinder and spheres prior to release. It shows a stopping cylinder as the spheres swing out on the end of the tether. And then it shows the cylinder being returned to its original rate of spin as the spheres swing past 90°, to tangent, and back into the cylinder.
What it shows is consistent with Newtonian arc (or linear) momentum conservation.
It shows that energy is not a conserved quantity; because the experiment does not show a 75% decrease in the spinning motion of the cylinder; because it is experimentally known that a small object cannot give its motion energy to a large object. A small object can only give its linear momentum to a larger object; this is from thousands of experiments with no exceptions.
Now it is experimentally known that when a large object gives its motion to a smaller object energy is not conserved.
The spheres appear to obtain the same speed as the cylinder's surface and seem to fly in formation with the surface of the cylinder as they come back to it. I know with shorter tethers the spheres strike the cylinder violently; so this was an interesting twist. Of course there were only a few frames of the spheres flying in formation so they may be still moving toward the surface. Not that there is any significance to this; but it is curious.
These machines conserve linear Newtonian momentum under a variety of circumstances (all circumstances no doubt).
re: energy producing experiments
I see no reason why an arm would not work.Â
No matter how many 4 lb units you have you would only be accelerating one at a time; so the others would be part of the wheel‘s mass.
The 4 lbs could stop the wheel (*Dawn Mission); but obviously it was not designed to do so; the wheel was not observed to even slow down. The fact that it does not slow down makes me wonder if it was really a working machine.
The stampers look totally unnecessary and they would also make you question the authenticity of the machine.
There are a few frames from a video on page 29 of this thread; these frames show about the same thing as the new cylinder and spheres video shows.
The newest cylinder and spheres is much more massive and the string (or tether) is almost half a circumference. The string comes out of the sphere seat. I made a video for you but Bessler's Wheel still only allows pictures.
The smallest object to stop a spin, that I recall, is the Yo-yo de-spin device used in the Dawn Mission. A 3 kilogram mass stopped 1460 kg. The only question is; what is conserved.
No matter how many 4 lb units you have you would only be accelerating one at a time; so the others would be part of the wheel‘s mass.
The 4 lbs could stop the wheel (*Dawn Mission); but obviously it was not designed to do so; the wheel was not observed to even slow down. The fact that it does not slow down makes me wonder if it was really a working machine.
The stampers look totally unnecessary and they would also make you question the authenticity of the machine.
There are a few frames from a video on page 29 of this thread; these frames show about the same thing as the new cylinder and spheres video shows.
The newest cylinder and spheres is much more massive and the string (or tether) is almost half a circumference. The string comes out of the sphere seat. I made a video for you but Bessler's Wheel still only allows pictures.
The smallest object to stop a spin, that I recall, is the Yo-yo de-spin device used in the Dawn Mission. A 3 kilogram mass stopped 1460 kg. The only question is; what is conserved.
re: energy producing experiments
I saw a Ferris Wheel type that had the radius of rotation drawn to the suspended mass. This made it appear that the wheel was off balance and would therefore rotate. But the radius of rotation is not to the suspended mass it is to the point on the arm where the mass is suspended. This is an example of the intuition that chases people into faulty designs.
I think another intuitive thought is that starting motion takes energy but stopping that motion is less energetic, or free. In an ocean liner the fuel or energy to bring it up to speed is exactly equal to the energy that would be needed to make it stop. The fuel is force; and it is applied for a period of time. You could apply half of the force and double the time but you are still going to have to get out your check book to make it stop.
In reality of course the ship coasts for 25 miles; (if my memory is correct) and there in lies the problem. This coasting makes it appear that the stopping is free; but the ocean must apply a force (a smaller force for a longer time) on the ship that is equal to the force (a large force for a short time) that put the ship in motion. If the ship was in trouble and had to be stopped quickly the same amount of fuel would be needed to make it stop, if we ignore ocean resistance.
The spinning rocket has no oceanic resistance, and there was a force applied to the rocket to make it spin. The same amount of force over time relationship will be needed to make it stop. After the yo-yo despin masses have been thrown off; the same amount of force over time will be needed to make the masses stop. These thrown off masses can not be moving at little league speed.
No comments are necessary; thanks.
I am working on a burn through release of the cylinder and spheres (a yo-yo despin device). It seems to be more exposed with no mechanical release around it; and it is simpler and cheaper.
I think another intuitive thought is that starting motion takes energy but stopping that motion is less energetic, or free. In an ocean liner the fuel or energy to bring it up to speed is exactly equal to the energy that would be needed to make it stop. The fuel is force; and it is applied for a period of time. You could apply half of the force and double the time but you are still going to have to get out your check book to make it stop.
In reality of course the ship coasts for 25 miles; (if my memory is correct) and there in lies the problem. This coasting makes it appear that the stopping is free; but the ocean must apply a force (a smaller force for a longer time) on the ship that is equal to the force (a large force for a short time) that put the ship in motion. If the ship was in trouble and had to be stopped quickly the same amount of fuel would be needed to make it stop, if we ignore ocean resistance.
The spinning rocket has no oceanic resistance, and there was a force applied to the rocket to make it spin. The same amount of force over time relationship will be needed to make it stop. After the yo-yo despin masses have been thrown off; the same amount of force over time will be needed to make the masses stop. These thrown off masses can not be moving at little league speed.
No comments are necessary; thanks.
I am working on a burn through release of the cylinder and spheres (a yo-yo despin device). It seems to be more exposed with no mechanical release around it; and it is simpler and cheaper.