Is the formula of the angular momentum conservation wrong?

[path_finder]

An interesting controversial approach:
http://sci.tech-archive.net/Archive/sci ... 00775.html

[pequaide]

Excellent work; you are quite correct.

At any time an object in rotation can be released from rotation and it will travel in a linear path with a linear velocity that is equal to the distance that was being traveled around the arc of the circle. It does not matter how big that circle is.

If an object is moving 5 m/sec in a large 20 meter circle and then is directed or caught into a small 1 meter circle; the distance traveled around the arc of the circle is still going to be 5 m/sec.

Angular momentum will not be conserved.

Kepler presented the formula (Angular momentum conservation) for comets and other satellites, where there is a huge gravitational acceleration for the velocity between apogee and perigee.

[pequaide]

I should say Excellent work franklinhu; you are quite correct.

Then this jemebius comes in and rebuts with complete gobbledygook and presents no experimental evidence whatsoever. Typical.

Franklin you are right on.

Here is the most important part. The numerical values of velocity that would give you angular momentum conservation are the same numerical values that would give you Kinetic Energy Conservation; and that Law is also, equally wrong.

This statement is not hard to prove experimentally; but it infuriates those that are stuck in the rut of KE. Actually they know KE is not conserved so they give the concept imaginary friends.  They make KE a part of a larger imaginary whole; while the truth evades them.

Let use the yo-yo despin experiment; as an example. Three kilograms stops 1420 kilograms. For angular momentum to be conserved the 3 kilograms must be moving 19.7 times faster. For kinetic energy to be conserved the 3 kilograms must be moving 21.7 times faster. So you are talking baseball speed.

A radius change from .5 meters to 12 meters is 24 times as long. And 24 times 3 kilograms x arc v =   1r x 1 m/sec  x 1420kg. If the rocket mass was spinning one meter per second then this equation is correct if arc v for the 3 kilograms equals 19.7 m/sec ; or 45 miles per hour; major league baseball pitchers throw in the 90s.

The actual spin velocity of the rocket was closer to 1.88 m/sec, and final velocity of the 3 kilograms would have been close to major league speed. But would not a catcher's glove suffice to prevent damage if the 3 kilograms returned to the rocket. No; they were concerned because the speed was much higher.

F= ma requires 890 m/sec for the 3 kilograms, speed around that of a low powered rifle. That is why they were concerned. Note that they do not tell you the speed; they would be at a lose to explain why it was so high.

[zoelra]

I can mathematically show that the conservation of angular momentum law applies to a specific set of movements and conditions. Hopefully the documents I've created and attached make sense. This is how I understand the concept. I'm not sure if the law holds (or applies) for motion not meeting the movements/conditions shown. For example, you can't forcefully move a weight outwards and expect momentum to be conserved.

1) Angular momentum is conserved when a rotating weight is allowed to move outward under its own momentum. When the outward movement is stopped, the radial component of velocity is lost, and the remaining velocity is tangential.

2) Angular momentum is conserved when a rotating weight is pulled inward by an external force. When the inward movement is stopped, the radial component of velocity is lost, and the remaining velocity is tangential.

* The initial velocity is v (lower case) and the change in velocity is shown with the yellow-orange arrow. The green line indicates the initial radial position and the red line indicates the final radial position. Although the drawings show show a single event (change in velocity), in a spiral pattern, there would be an infinite number of infinitesimally small changes. Can anyone say Calculus ...

[cloud camper]

Excellent Z – It’s interesting that we have created an artificial gravitational system that exactly mimics our everyday one.

We can create artificial GPE in this system by raising weights with actual physical work to a higher (smaller radius) position closer to the center of rotation but this work does nothing to change the total angular momentum of the rotating system.

What is very interesting to me is where does this artificially created GPE go when the system stops rotation?

It simply vanishes!

The stored GPE that had been created by placing weights at different heights (radius from COR) simply disappears because the rotating reference frame that it was created in no longer exists.

This is an actual annihilation of energy folks. This is not supposed to happen according to COE.

Dunes?

[zoelra]

Thanks CC.

I didn't stress enough that it is the loss of the radial component of velocity that makes the law hold true.


[edit] Don't beat me up now CC, but if you think the momentum proof is cool, just wait until I prove to you that there is energy to be gained from CF.

[cloud camper]

OK Z - Good luck but you just showed mathematically that it doesn't matter where you place the weights, angular momentum of the wheel does not change.

What I'm trying to show is that there are two separate energy fields contained within a rotating system which are almost completely independent of each other.

The first is the angular momentum field. Once a wheel is under rotation, it contains an exact quantity of angular momentum that cannot be changed by moving weights in or out. You just proved this mathematically.

The second is the internal GPE field. This field is at 90 degrees to the angular momentum field. The quantity of energy stored in this field is highly variable depending on the radius of the weights from the COR. The energy in this field can be created and destroyed at will.

These two fields do not interact directly since they are at right angles to each other.

An Electromagnetic Wave is composed of a electric and magnetic wave at
90 degrees to each other and both store energy. Interesting huh?

[zoelra]

You are correct CC, angular momentum doesn't change, but CF is present as long as the moving weight is constrained in a way that the force can be used.

I have completed a mathematical model of the apparatus that will function as a prime mover and all I can say is it shows positive energy accumulation. However, before I move forward with a build, I am going continue to think about the design to make sure I haven't overlooked any aspect of the movements and thus energy losses.

[rlortie]

CC wrote:

The second is the internal GPE field. This field is at 90 degrees to the angular momentum field.

Not meaning to be finicky, but by the time you throw in inertia under the guise of Cf, I believe you find that your 90 degrees will end up being closer to 80 degrees. That is were it falls under the "work" calculations.

Pay no attention, just taking a short break from the shop!

Ralph

[zoelra]

Interesting idea CC ...

I suspect we shall be discussing this idea much more in the future.

[Dunesbury]

Excellent Z – It’s interesting that we have created an artificial gravitational system that exactly mimics our everyday one.

We can create artificial GPE in this system by raising weights with actual physical work to a higher (smaller radius) position closer to the center of rotation but this work does nothing to change the total angular momentum of the rotating system.

What is very interesting to me is where does this artificially created GPE go when the system stops rotation?

It simply vanishes!

The stored GPE that had been created by placing weights at different heights (radius from COR) simply disappears because the rotating reference frame that it was created in no longer exists.

This is an actual annihilation of energy folks. This is not supposed to happen according to COE.

Dunes?

No, it didn't vanish. Rotating weight loses energy to environment in absence of external torques. It stops rotation due to non-conservative forces.

What I'm trying to show is that there are two separate energy fields contained within a rotating system which are almost completely independent of each other.

The first is the angular momentum field. Once a wheel is under rotation, it contains an exact quantity of angular momentum that cannot be changed by moving weights in or out. You just proved this mathematically.

The second is the internal GPE field. This field is at 90 degrees to the angular momentum field. The quantity of energy stored in this field is highly variable depending on the radius of the weights from the COR. The energy in this field can be created and destroyed at will.

Momentum is not energy. Different units. Mass of wheel under rotation is kinetic energy.

Energy is scalar, it has no direction.

http://www.grc.nasa.gov/WWW/k-12/airplane/vectors.html

"Internal GPE field" is confusing description. Can you think of better wording?
The variable from changing a weight's radius is its velocity. Whenever velocity changes then its kinetic energy changes, but it isn't created or destroyed. The radius can be changed internally, as in skater arms and legs, or externally.

Angular momentum formula is correct. Here is experiment from ISS:

http://www.youtube.com/watch?v=C8kCKPo5lf0

[Wubbly]

Here was another explanation of the conservation geometry from 2012.

http://www.besslerwheel.com/forum/download.php?id=10697

franklin Hu performed an updated experiment here:
http://www.youtube.com/watch?v=9MGQJar8 ... SM4lz2-aYw

we discussed it at length in 2013 in this thread here:
http://www.besslerwheel.com/forum/viewt ... sc&start=0

[cloud camper]

Excellent Z – It’s interesting that we have created an artificial gravitational system that exactly mimics our everyday one.

We can create artificial GPE in this system by raising weights with actual physical work to a higher (smaller radius) position closer to the center of rotation but this work does nothing to change the total angular momentum of the rotating system.

What is very interesting to me is where does this artificially created GPE go when the system stops rotation?

It simply vanishes!

The stored GPE that had been created by placing weights at different heights (radius from COR) simply disappears because the rotating reference frame that it was created in no longer exists.

This is an actual annihilation of energy folks. This is not supposed to happen according to COE.

Dunes?

No, it didn't vanish. Rotating weight loses energy to environment in absence of external torques. It stops rotation due to non-conservative forces.

What I'm trying to show is that there are two separate energy fields contained within a rotating system which are almost completely independent of each other.

The first is the angular momentum field. Once a wheel is under rotation, it contains an exact quantity of angular momentum that cannot be changed by moving weights in or out. You just proved this mathematically.

The second is the internal GPE field. This field is at 90 degrees to the angular momentum field. The quantity of energy stored in this field is highly variable depending on the radius of the weights from the COR. The energy in this field can be created and destroyed at will.

Momentum is not energy. Different units. Mass of wheel under rotation is kinetic energy.

Energy is scalar, it has no direction.

http://www.grc.nasa.gov/WWW/k-12/airplane/vectors.html

"Internal GPE field" is confusing description. Can you think of better wording?
The variable from changing a weight's radius is its velocity. Whenever velocity changes then its kinetic energy changes, but it isn't created or destroyed. The radius can be changed internally, as in skater arms and legs, or externally.

Angular momentum formula is correct. Here is experiment from ISS:

http://www.youtube.com/watch?v=C8kCKPo5lf0

Dunes – really appreciate your response but it is incorrect and confusing IMHO.

Momentum is not energy – yes that is correct but KE does not change either. Let’s use the Franklin Hu Youtube experiment as reference - thanks Wubbles!

First we need the concept of radius of gyration. This is the radius from COR where we could place all the mass in the system in an infinitely narrow band and not have to deal with mass spread all over as in a flywheel (and avoid some nasty calculus which I forgot anyway).

So with a given overall mass KE=1/2MV^2. The idea here is that during rotation, the mass located at the radius of gyration for the system is travelling at a tangential speed V relative to a stationary background.

Now we reduce the radius of gyration by moving weights toward the center. Then, with the mass moving at the same tangential speed as before (since we only moved weights at 90 degrees to the tangential direction), this mass is following a much smaller radius. So the rpm increases as it now takes less time to complete a circle at the SAME TANGENTIAL SPEED as before.

So KE has not changed just because we reduced the radius of gyration. KE is still given by the same formula as it does not care about radius.

We did nothing to add or subtract velocity to the mass circulating at the original radius of gyration. All we did was to tighten up the radius the mass was travelling in, creating a smaller radius of gyration.

So KE and AM remain a constant whether we move mass in or out. KE only appears to increase because the rpm has increased. But this is false because the tangential speed of the mass at the radius of
gyration is still the same V relative to a stationary background as before.

This is all observed in the Franklin Hu experiment.

I know you know physics well enough that you won’t claim that energy is increased in a rotating system simply by moving weights in.

Then I confused you with the term “internal GPE field�.

This is the same vertical PE field (mgh or mass x gravity x height) that is experienced in an inertial (non rotating) reference frame except that it exists only within the boundaries of the rotating system.

If all mass is placed at the rim there is no internal GPE as the height is zero. If all mass is located near the COR but has the capability of migrating to the rim, the energy would then be described something like mgh as it has a potential relative to how far in from the rim it is located during rotation.

You say energy is a scalar and has no direction, this is absolutely correct. However energy always is contained within some sort of field, which often does have an orientation. This is then called a vector field
rather than a scalar field. In physics if two vector fields are at 90 degrees to each other, they cannot affect each other.

The angular momentum field is oriented in a tangential direction to rotation. The internal GPE field is located at 90 degrees to this and is oriented toward the COR.

These fields have nothing to do with each other except being caused by mass in rotation.

We can observe this in the Hu experiment. When the author sets the system in rotation it has a fixed amount of AM that moving weights in or out does not change.

What does change is the internal GPE (mgh) quantity when the author pulls on the string. Pulling on the string creates energy in the internal GPE field without affecting the AM field in any way. Then this energy is returned when the string is released.

We then have two independent fields capable of storing energy in a rotating system. One is fixed, the other is variable, depending on where the mass is located when rotation is first initiated.

[daxwc]

Cloud:

Then I confused you with the term “internal GPE field�.

This is the same vertical PE field (mgh or mass x gravity x height) that is experienced in an inertial (non rotating) reference frame except that it exists only within the boundaries of the rotating system.

If all mass is placed at the rim there is no internal GPE as the height is zero. If all mass is located near the COR but has the capability of migrating to the rim, the energy would then be described something like mgh as it has a potential relative to how far in from the rim it is located during rotation.

That is interesting CC, is that a concept you developed? Is it named something different or where can I study it more?

[Fletcher]

CC ..

Take a look at these - the first two attachments are Wubbly's spreadsheet privately modified by me for my own use back in May 2013 (sorry for butchering them Wubbly).

The second two are sims that show the same results as the predictive spreadsheets.

Check what happens to linear velocity & KE etc.

Do they conform to what you said above ?