Is the formula of the angular momentum conservation wrong?

[rlortie]

zoelra,

When your radial motion of the marble drops into the funnel orifice or axis, are you you not exchanging/loosing any Angular motion for vertical linear motion?

I would think that any built up angular or Cf would be lost at this point.

[Fletcher]

zoelra ..

Going back to few posts of yours - AM is about an(y) arbitrary point - if the puck string could instantanously shorten & attach the free end to the new pin position then that would be the new arbitrary point wouldn't it ?


P.S. Ralph .. the wheel circumference is doing apprx 5 m/s or 18 km/hr.

[zoelra]

@pequaide,

I'm not sure anyone put speed detection on any of the experiments, but the videos that depict people spinning (sitting in a chair) then pulling in weights in their hands (the ice skater effect) would seem to suffice. I suppose the contention is that the speed (v=rw) remains constant. r and w are inversely proportional rather than r^2 and w as would be expected if angular momentum were conserved.

If he agrees with the attached graphical proofs, then all we need to do is devise or find experimental evidence that fits the movements. I would take the spinning person pulling in weights approach and find a way to digitally measure the angular speed. Easier said than done I'm sure.

[zoelra]

@Fletcher,

You asked:
"Going back to few posts of yours - AM is about an(y) arbitrary point - if the puck string could instantanously shorten & attach the free end to the new pin position then that would be the new arbitrary point wouldn't it ?"

I was making a general statement. Yes to your question about the new pin point. AM would NOT be conserved regardless of the pin position. I hope you concur.

[zoelra]

@Ralph,

You asked:
"When your radial motion of the marble drops into the funnel orifice or axis, are you you not exchanging/loosing any Angular motion for vertical linear motion? I would think that any built up angular or Cf would be lost at this point."

I'm not sure Ralph, my comment was more of a question that I will have to investigate. Have you ever seen the coin devices where you drop a coin in a slot and it rolls out tangentially into a large funnel vortex. The coins rolls around picking up speed as it moves down the funnel, then eventually drops out the bottom into a collection container. Based on what I know of Uncle's Toy, the same thing happens, but with a marble. The marble shoots into the funnel with a certain speed and as it rotates around the funnel, CF keeps it from dropping quickly. Gravity acts on the marble pushing it down, but due to the shape of the funnel, the marble is pushed inward as well. When viewed from above, as the marble falls slightly relative to the movement around the outside, the marble is pushed inwards in a spiral shape which could indicate angular momentum is conserved. If this is true, then we have found a way to use gravity and the Earth's inertia to increase the energy of a moving object. Just a theory for now.

[Grimer]

@ zoelra

Here's the post I was thinking of. It was written the year before you joined the forum.

http://www.defza.com/notes/life/energy/35/

Bruce Welsh is an electronics engineer with the open spirit which has been devoted to alternative energies for twenty years. It is convinced that one can build machines with on-unit.

He had an uncle who liked to arrange, to invent. One day, old Bruce of seven or eight years, returned visit to the uncle who showed to the grandfather the new play that it had made for his children (it had six of them).

The play made in the sixty centimetres height for a base of thirty centimetres square. It consisted of a slope in spiral of three turns and half. At the bottom of the slope a paddle wheel, connected by some gears to an elevator was placed going up to the top of the play where a hopper furnished with ten balls was. An opening to rocker in the hopper made it possible to let pass, one by one the balls which went down the slope into three to five seconds.

The ball touched the paddle wheel what gave a small upswing which released another ball whereas the first was on the elevator and went towards the hopper. And so on.

There were five balls at the same time on the elevator and the once launched play did not stop any more. To begin, all the balls were to be in the hopper and Bruce remembers to be thundered by the uncle because it had touched the paddle wheel, thus stopping the play started again soon by the uncle. And, several hours after, the play always functioned.

Did the uncle know that it had violated the laws of physics?

Its descendants do not know any more what became this play, it is probable that the uncle in recovered the parts as it was its practice to rebuild another thing, unless it does not sleep yet in an old farm, in dust… They do not remember either to have seen other apparatuses functioning in an autonomous way, nor of engine on the play, but know that the play had stopped afterwards weeks and simply set out again after being cleaned.

Foot-note: the slope in spiral is indeed a vortex and it seems that in a certain way the vortices add energy, one unceasingly finds them in many ideas related to on-unit.

(KeelyNet source of the 14/12/97)
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Posted: 25th May 2009, 10:01 pm Post subject: re: Serendipity

...
So I guess I'm asking Grimer is a Bernoulli vortex spiral any different from an ordinary straight incline ?

Fletcher put the above question to me a year ago. Since then I have had plenty of time to think about it and the discussions I have had with my builder (Vina1) have helped me to formulate the answer, which is yes, a Bernoulli vortex spiral is different from an ordinary straight incline.

I suppose the simplest explanation is that the spiral forces the falling ball towards the centre which implies work being done on the ball which has to appear in some form or other. The fact that work is being done is seen more easily if the section on which the ball is sitting and which is pushing the ball towards the centre is replaced by a string pulling the ball towards the centre. If one pulls the ball towards the centre then the ball will rise against gravity thus showing that work is being done on the ball.

So it seems possible that work done on the ball by the vortex spiral is leading to an increase in velocity, in KE, over that which would be obtained by a straight drop or a drop down a slope which is straight in plan.

Let's explore the matter further.

Consider the following diagram which shows a ultra heavy globe, earth mass say, being dropped on a roller mounted wedge slope with a height to horizontal length ratio of 1:4. Let the mass of the slope be negligible and the coefficient of friction between the globe and the slope approach zero.

Now the globe will fall vertically under gravity and squeeze the slope out as it does so. The horizontal velocity of the slope will be four times the vertical velocity of the earth mass

This means that the when the ball reaches the rollers the velocity of the slope will be four times the velocity it would have had if it had fallen vertically the same distance as that fallen by the ball.

Now what is taking place in the case of the vortex spiral and a ball-bearing is the inverse of the above. It is the vortex spiral attached to the mass of the earth which the high inertia object corresponding to the heavy globe and the ball-bearing which corresponds to the wedge being squeezed.

Another way of looking at it is to see the ball bearing as being a rider on the wall of death as it enters the steepest section of the vortex. In effect the riders are kept in place by the action of ersatz gravity .....



..... which exerts a greater force on the rider than natural gravity. For slopes below 45 degrees natural gravity dominates ersatz gravity. For slopes greater than 45 degrees it is the other way around.

The concept of artificial gravity will be familiar to all 2001 fans as the way is which gravity is simulated on a space station.



So Uncle Welsh had the action of natural gravity boosted by the action of ersatz gravity and this is how he managed to get a continuous flow of marbles around his toy.

From what I remember of vortex flow in liquids the speed of flow steadily increases until it reaches the velocity of sound whereupon the remaining central core revolves as a solid cylinder.
This fits comfortably with the above interpretation.

How on earth has this been missed. The answer is it hasn't. Bessler didn't miss it. Keenie didn't miss it and Bruce's uncle didn't miss it either.

Also, one has to bear in mind the way science has progressed over the twentieth century. Simone Weil, had the situation bang to rights when in her essay, "La Science et nous" she wrote,

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What is disastrous is not the rejection of classical science but the way it has been rejected. It is wrongly believed it could progress indefinitely and it ran into a dead end about the year 1900; but scientists failed to stop at the same time in order to contemplate and reflect upon the barrier, they did not try to describe it and define it and, having taken it into account, to draw some general conclusion from it; instead they rushed violently past it, leaving classical science behind them.

And why should we be surprised at this? For are they not paid to forge continually ahead? Nobody advances in his career, or reputation, or gets a Nobel prize, by standing still. To cease voluntarily from forging ahead, any brilliantly gifted scientist would need to be a saint or a hero, and why should he be a saint or a hero? With rare exceptions there are none to be found among the members of other professions.

So the scientists forged ahead without revising anything, because any revision would have seemed a retrogression; they merely made an addition.

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[Fletcher]

@Fletcher,

You asked:
"Going back to few posts of yours - AM is about an(y) arbitrary point - if the puck string could instantanously shorten & attach the free end to the new pin position then that would be the new arbitrary point wouldn't it ?"

I was making a general statement. Yes to your question about the new pin point. AM would NOT be conserved regardless of the pin position. I hope you concur.

I think I'd like to hear Wubbly & Dwayne's opinions about that zoelra.

CoAM is assumed for a constant axis point where no external torque is applied once an object is circulating, IINM.

[zoelra]

@Fletcher,

I have to assume this is the case since it doesn't meet the requirement for conservation of angular momentum (weight pulled in radially). Sorry I didn't mean to put you on the spot for an answer.

Should someone disagree about the changing pin position and its affect on AM, I would love to see a graphical or mathematical proof so I could investigate further.

[zoelra]

Thanks Grimer,

I actually saw that post some time ago. I agree that the shape of the funnel/vortex is critical. You would want a shape that compliments CF to keep the rotating ball from dropping too fast, or at just the right speed to produce the effect you want.

Gravity, along with the Earth's inertia keeping the funnel in place, and of course the shape of the funnel, may provide a push that is equivalent to the pull in an ordinary rotating object.

To be honest, I'm not sure you even need to worry whether angular momentum is conserved. As long as the design adds force (or velocity) in the plane of motion and in the direction of movement, energy should be gained. The vertical dimension may act like stacked layers of circular motion.

I'm never going to beat Trevor to the punch if I keep getting sidetracked like this.

[Fletcher]

I'm never going to beat Trevor to the punch if I keep getting sidetracked like this.

That may be true & discussions like this may distract us, but at least they are interesting & informative - this particular one tells us that KE can disappear in large amounts without any external torque applied whilst maintaining AM [conserved quantity] - perhaps the antithesis is true & the door is open to mechanically gain KE in similar circumstances ?

Which brings me to your next point although you were talking about the vortex spiral.

To be honest, I'm not sure you even need to worry whether angular momentum is conserved.

As long as the design adds force (or velocity) in the plane of motion and in the direction of movement, energy should be gained.

The vertical dimension may act like stacked layers of circular motion.

I'm going to propose a thought experiment myself that I've been mulling for some time - I may post it on my own thread because it is relevant to the RBGS design where I first thought of it [but the example I'll use is the radial displaced masses we are familiar with here, moving outwards etc, as I think they are complimentary] - if it's sensible it won't conserve AM I should think - or maybe someone will quickly dismiss it for a good reason.

[Fletcher]

Here's a 'Khan Academy' presentation I just found discussing motion around a fixed axis with no external torques - good refresher.


https://www.khanacademy.org/science/phy ... r-momemtum

[Grimer]

"Angular momentum is constant when there is no net torque."

That is the key statement.

But when you pull in the mass at right angles to the perimeter you are doing work at right angles and you are not affecting the torque since F•cos(90) = 0

[Dunesbury]

Pulling rotating mass in at right angle to perimeter is doing work because part of force is not at right angle to perimeter, because the mass is rotating. So there is net torque, and angular momentum would increase.

[daxwc]

http://www.youtube.com/watch?v=xWCmXvWM0ZY

http://www.youtube.com/watch?v=J-OY0KxRdgQ

[Fletcher]

"Angular momentum is constant when there is no net torque."

That is the key statement.

But when you pull in the mass at right angles to the perimeter you are doing work at right angles and you are not affecting the torque since F•cos(90) = 0

Pulling rotating mass in at right angle to perimeter is doing work because part of force is not at right angle to perimeter, because the mass is rotating. So there is net torque, and angular momentum would increase.

Dunesbury .. this is what I think Ralph was trying to say the other day - there was a vector diagram shown in some thread [can't remember where right now] that showed an advance component of vector force & a retarding component of vector force when masses moved inwards & outwards respectively.

If I find it again I will post it. [Found something similar from Wubbly - uses geometry like zeorla did]

Please Read: http://www.besslerwheel.com/forum/viewt ... 6905#96905

What we do know is that the acceleration vector changes as the velocity vector changes.

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Both yourself & Frank appear to be in complete disagreement ?