Circumventing Newton's third law through Euler Inertial Forces

[joigus]

20 minutes ago, John2020 said:

Crucial question: Does the acceleration of mass m_T is attributed to a real or to a fictitious force (Euler Force)?  

In what frame of reference? You don't seem to be aware that accelerations are frame-dependent. You've been asked this before, I think. In a FOR sitting with the ship initially at rest there are no fictitious forces. There are Newton pairs, and they cancel.

In the Lagrangian formalism, they're expressed as some kind of integrable constraint: f_1(angle)d(angle) = f_2(angle')d(angle') and they don't appear in the COM motion. You don't even have to think about them as "forces."

Technically we know them as "ignorable coordinates." I wonder why.

Edit: https://en.wikipedia.org/wiki/Noether's_theorem#Historical_context

Quote

Thus, the absence of the ignorable coordinate qk from the Lagrangian implies that the Lagrangian is unaffected by changes or transformations of qk; the Lagrangian is invariant, and is said to exhibit a symmetry under such transformations. This is the seed idea generalized in Noether's theorem.

Several alternative methods for finding conserved quantities were developed in the 19th century, especially by William Rowan Hamilton. For example, he developed a theory of canonical transformations which allowed changing coordinates so that some coordinates disappeared from the Lagrangian, as above, resulting in conserved canonical momenta. Another approach, and perhaps the most efficient for finding conserved quantities, is the Hamilton–Jacobi equation.

(My emphasis.)

13 minutes ago, joigus said:

and they cancel.

Edit 2: Well, they don't "cancel," as @swansont pointed out on a previous thread, as each acts on a different part of the system. But they can vectorially be added up in the eqs. of the overall motion and don't play a role at all in its COM motion.

13 minutes ago, joigus said:

Technically we know them as "ignorable coordinates." I wonder why.

Sorry, I made a mistake. Ignorable coordinates are the COM coordinates (they don't appear in the Lagrangian.)

The other aspect is the constraint:

f_1(angle)d(angle) = f_2(angle')d(angle')

So that the constraint is integrable and you can describe the internal motion by just one coordinate. Which doesn't appear in the potential energy (because there is no external potential) so that it is, in fact, ignorable too.

Edited October 11, 2020 by joigus
Addition

[John2020]

2 minutes ago, joigus said:

In what frame of reference? You don't seem to be aware that accelerations are frame-dependent. You've been asked this before, I think. In a FOR sitting with the ship initially at rest there are no fictitious forces. There are Newton pairs, and they cancel.

The acceleration of mass m_T appears as "real" force from the inertial frame (skeleton), however it is is in essence fictitious and attributed to the rotating frame. In this regard, I would agree with swansont but we cannot ignore the mechanism just in the name of math (this is where you misinterpret how the construction works). The mechanism must be visible/justifiable when we describe the motion of the system with forces that means in the expression that shows the advancing of mass m_T, the fictitious force must be clearly identifiable (and not as a real force). A real force wouldn't be dω depended.

11 minutes ago, joigus said:

In the Lagrangian formalism, they're expressed as some kind of integrable constraint: f_1(angle)d(angle) = f_2(angle')d(angle') and they don't appear in the COM motion. You don't even have to think about them as "forces."

Technically we know them as "ignorable coordinates." I wonder why.

Because that kind of Lagrangian you use assumes all internal happening are action-reaction pairs. This is not evident in our case. While mass m_T is being accelerated do you see any force to apply in the opposite direction upon the rest of the system?

[joigus]

1 minute ago, John2020 said:

 

Because that kind of Lagrangian you use assumes all internal happening are action-reaction pairs. This is not evident in our case. While mass m_T is being accelerated do you see any force to apply in the opposite direction upon the rest of the system?

In what frame of reference?

Ficticious forces only appear (as apparently reaction-less) in non-inertial frames. Are you sitting on the turning "nut" whence you're going to measure your ship's overall motion? That would be inconsistent.

This very much reminds me of another thread in which a user has been rejecting special relativity for years due to the mixing in his mind of lines of reasoning that can only be applied to one or the other frame of reference.

[John2020]

2 minutes ago, joigus said:

In what frame of reference?

Ficticious forces only appear (as apparently reaction-less) in non-inertial frames. Are you sitting on the turning "nut" whence you're going to measure your ship's overall motion? That would be inconsistent

In the construction's skeleton (inertial frame of reference). I am sitting inside the skeleton (inertial frame of reference) but not on the rotating frame (translation screw).

[swansont]

13 hours ago, John2020 said:

I will make you a simple question: What is the cause behind the acceleration of mass m_T, a real or a fictitious force?

The screw exerts a force on the mass. The mass exerts a force on the screw. Real forces.

That makes analyzing your list moot, as it starts with this force being fictitious 

[John2020]

10 minutes ago, swansont said:

The screw exerts a force on the mass. The mass exerts a force on the screw. Real forces.

The forces you mention are in essence the real action-reaction collinear forces pair, that are perpendicular to the acquired momentum of mass m_T. There are no real forces along the axis of rotation of the translation screw, just the fictitious one (Euler force).

Edited October 11, 2020 by John2020

[swansont]

1 minute ago, John2020 said:

The forces you mention are in essence the real action-reaction collinear forces pair, that are perpendicular to the acquired momentum of mass m_T. There are no real forces along the axis of rotation of the translation screw, just the fictitious one (Euler force).

Bollocks. 

[John2020]

14 minutes ago, swansont said:

That makes analyzing your list moot, as it starts with this force being fictitious 

No.As I mentioned above the action-reaction pair is perpendicular to the acquired momentum of mass m_T that implies mass m_T acceleration is attributed to an Euler Force. Just think the following: If the translation screw wouldn't rotate, would mass m_T advance to the right just by pushing it with a real force from its left side? The answer is obviously no. Because the rod is threaded that inhibit the appearance of real forces along the axis of rotation of the translation screw.

Edited October 11, 2020 by John2020

[swansont]

Make it simple: a screw and a single pin, so we can analyze one point. The screw has a pitch, so as the screw rotates, the point of contact moves parallel to the axis of rotation, exerting a force.

 

1 minute ago, John2020 said:

No.As I mentioned above the action-reaction pair is perpendicular to the acquired momentum of mass m_T that implies mass m_T acceleration is attributed to an Euler Force.

Mentioning it doesn’t mean you are right.

In an inertial frame, there is no Euler force.

[John2020]

18 minutes ago, swansont said:

Make it simple: a screw and a single pin, so we can analyze one point. The screw has a pitch, so as the screw rotates, the point of contact moves parallel to the axis of rotation, exerting a force.

If the translation screw wouldn't rotate, would mass m_T advance to the right just by pushing it with a real force from its left side? The answer is obviously NO. Because the rod is threaded that inhibits the appearance of real forces along the axis of rotation of the translation screw.

18 minutes ago, swansont said:

In an inertial frame, there is no Euler force.

I agree. Let's take it step by step again:

1.Inertial frame: There is no Euler force

2.Rotating frame: There is Euler force

3.Inertial frame:The rotating frame is an intrinsic part of the inertial frame that means the whole is considered as a single Inertial frame

4.Rotating frame: Euler force is the cause behind the acceleration of mass m_T without causing a reaction upon the rest of the inertial frame

5.Inertial frame: Due to (3) and (4) the COM of the Inertial frame will change along with its momentum

6.Inertial frame: It will start to accelerated because of (5)  

Is there any objection on the above?

Edited October 11, 2020 by John2020

[swansont]

3 minutes ago, John2020 said:

If the translation screw wouldn't rotate, would mass m_T advance to the right just by pushing it with a real force from its left side? The answer is obviously NO. Because the rod is threaded that inhibits the appearance of real forces along the axis of rotation of the translation screw.

The threaded rod would impede progress, sure. So what? That exerts a force as well. There would be contact between the threads of the rod and the housing.

It doesn’t “inhibit the presence of real forces” 

[John2020]

8 minutes ago, swansont said:

It doesn’t “inhibit the presence of real forces” 

The topology of the threads of the translation screw is a helix that means the action-reaction pair is forced to follow the helix trajectory that implies the action-reaction pair is perpendicular to the acquired momentum of mass m_T. 

Edited October 11, 2020 by John2020

[joigus]

15 hours ago, John2020 said:

Let's put aside the cosmological stuff because I cannot support through my work. They are just assumptions, OK. Consider, the telescopes cannot observe down to the big bang where there even GR is expected to break. So as long an angular velocity is so negligible even at a distance several thousands of light years from the center of the Universe, GR will still work. Again, let this subject for another thread and another paper (that derives, the mass, the radius (approx. 1E28m much larger from what is assumed today), the acceleration of the Universe, the quantum length (it is much smaller (approx. 1E-58 m) than planck length), the thermodynamic temperature of the Universe approx. 2.76 Kelvin just from the fundamental constants and the concept of this work, without using the hubble constant. 

You cannot dismiss essential points by saying they are "just assumptions" (to be addressed later) and then rush to mention in passing Planck's length (or a tiny fraction of it?), alleged axial anysotropies in the CMB (unobserved), etc. and then expect everybody to believe these bizarre phenomena that would require a complete re-work of everything physics is based on, all coming from a simple diagram. Your machine cannot turn the world as we know it upside down in one fell swoop. The physical principle you're up against is even valid for systems of quantum fields and is a version of Ehrenfest's theorem. I would (and will) demand nothing short of arguments of such dazzling clarity as to make me think it's worth giving up everything I've learnt during a lifetime.

1) Momentum conservation is tied to space symmetries

2) Fictitious forces only appear in non-inertial systems

3) Internal constrictions can always be resolved into action-reaction pairs in the inertial frame (I told you why this is necessary to be able to apply Newton's laws either to whole systems or to their constituent parts)

4) Mass transfer only results in thrust when mass is permanently ejected, not when it's kept inside the system

May I also remind you of the adage,

"Extraordinary claims require extraordinary evidence."

Carl Sagan

[Ghideon]

2 hours ago, John2020 said:

No. What you are saying would happen when there were external torques in the system and the translation screw would extend beyond the housings (in order the construction to advance counterclockwise).

In Fig.1-Upper, we have just internal torques that means the translation screw accelerates clockwise while mass m_T advances counterclockwise. But as you may see there are two linear guides that restrict a counterclockwise rotation of mass m_T. This restriction forces mass m_T to advance to the right (that is inherently counterclockwise). In other words, when one removes the linear guides and holds the drive nut (m_T) with his hand, when the linear actuator is powered and the translation screw accelerates clockwise, the construction will advance to the left while the drive nut (m_T) to the right (conservation of angular momentum).

There is an engine somewhere in the device? That engine applies the appropriate torque to start rotating the screw? 

[John2020]

1 minute ago, Ghideon said:

There is an engine somewhere in the device? That engine applies the appropriate torque to start rotating the screw? 

Yes. I mentioned this on my first post. See red colored text. The power supply and motor are enclosed in the housings that hold the translation screw.

4 minutes ago, joigus said:

1) Momentum conservation is tied to space symmetries

2) Fictitious forces only appear in non-inertial systems

3) Internal constrictions can always be resolved into action-reaction pairs in the inertial frame (I told you why this is necessary to be able to apply Newton's laws either to whole systems or to their constituent parts)

4) Mass transfer only results in thrust when mass is permanently ejected, not when it's kept inside the system

May I also remind you of the adage,

"Extraordinary claims require extraordinary evidence."

Carl Sagan

I agree. This is my answer:

1.Inertial frame: There is no Euler force

2.Rotating frame: There is Euler force

3.Inertial frame:The rotating frame is an intrinsic part of the inertial frame that means the whole is considered as a single Inertial frame

4.Rotating frame: Euler force is the cause behind the acceleration of mass m_T without causing a reaction upon the rest of the inertial frame

5.Inertial frame: Due to (3) and (4) the COM of the Inertial frame will change along with its momentum

6.Inertial frame: It will start to accelerated because of (5)  

Is there any objection on the above?

[Ghideon]

1 minute ago, John2020 said:

Yes. I mentioned this on my first post. See red colored text. The power supply and motor are enclosed in the housings that hold the translation screw.

So when the screw is beginning to rotate, let's say clockwise the engine wants to rotate counter clockwise. Since the engine is bolted into the frame of the device the device will rotate. The sum of angular momentum of the screw* and the angular momentum of the rest will be zero.

 

*) Screw + the required parts of the engine that is attended to it 

 

[John2020]

6 minutes ago, Ghideon said:

So when the screw is beginning to rotate, let's say clockwise the engine wants to rotate counter clockwise. Since the engine is bolted into the frame of the device the device will rotate. The sum of angular momentum of the screw* and the angular momentum of the rest will be zero.

That would be possible when there wouldn't be an accelerating mass m_T. I am expecting the behavior you just mentioned to be negligible in Fig.1-Upper because the angular momentum of the device (Ideal Machine) is transferred to mass m_T. 

What is your view on the below:

1.Inertial frame: There is no Euler force

2.Rotating frame: There is Euler force

3.Inertial frame:The rotating frame is an intrinsic part of the inertial frame that means the whole is considered as a single Inertial frame

4.Rotating frame: Euler force is the cause behind the acceleration of mass m_T without causing a reaction upon the rest of the inertial frame

5.Inertial frame: Due to (3) and (4) the COM of the Inertial frame will change along with its momentum

6.Inertial frame: It will start to accelerated because of (5)  

Is there any objection on the above?

[joigus]

6 minutes ago, John2020 said:

1.Inertial frame: There is no Euler force

=> Newton pairs => No contribution to overall motion

7 minutes ago, John2020 said:

2.Rotating frame: There is Euler force

=> Not significant to COM evolution equations

9 minutes ago, John2020 said:

3.Inertial frame:The rotating frame is an intrinsic part of the inertial frame that means the whole is considered as a single Inertial frame

=> Again. Rotation of one part not relevant to COM coordinates motion

9 minutes ago, John2020 said:

4.Rotating frame: Euler force is the cause behind the acceleration of mass m_T without causing a reaction upon the rest of the inertial frame

=> No. Fictitious forces only relevant to objects moving with respect to non inertial frames (nut, bolt, etc.) subject to acceleration. Not relevant to COM motion.

11 minutes ago, John2020 said:

5.Inertial frame: Due to (3) and (4) the COM of the Inertial frame will change along with its momentum

=> Already addressed. Non-sequitur

11 minutes ago, John2020 said:

6.Inertial frame: It will start to accelerated because of (5)  

=> Already addressed. Non-sequitur

6 minutes ago, Ghideon said:

So when the screw is beginning to rotate, let's say clockwise the engine wants to rotate counter clockwise. Since the engine is bolted into the frame of the device the device will rotate. The sum of angular momentum of the screw* and the angular momentum of the rest will be zero.

That's exactly what I think. There will also be a push and pull effect along the axial direction, to be studied in terms of action and reaction, if you will. Again: no overall momentum. Even though the detailed analysis would be quite involved. Assuming there's no friction, any angular displacement would result in a linear displacement, depending on the pitch of the screw.

As said, and so far unanswered, the Lagrangian formalism makes it quite transparent that there can be no thrust for the COM system. It is true that the Lagrangian formalism can only be applied to conservative systems. But friction would only make it worse, not better, for the OP's claims.

[John2020]

28 minutes ago, joigus said:

=> Newton pairs => No contribution to overall motion

The Newton pairs appear perpendicular to the acquired momentum of mass m_T since they follow the helix trajectory of the thread upon the translation screw.

28 minutes ago, joigus said:

=> Not significant to COM evolution equations

You overlook something here. The rotating frame is an intrinsic part of the Inertial frame therefore is significant for the COM.

28 minutes ago, joigus said:

=> Again. Rotation of one part not relevant to COM coordinates motion

 The rotating frame is an intrinsic part of the Inertial frame therefore is significant for the COM.

28 minutes ago, joigus said:

=> No. Fictitious forces only relevant to objects moving with respect to non inertial frames (nut, bolt, etc.) subject to acceleration. Not relevant to COM motion.

Drive nut (mass m_T) is being affected by the accelerating rotation of the translation screw that implies a Fictitious force (Euler) is at play. It is relevant to COM because it is the cause behind a reactionless accelerating transfer of mass m_T.

28 minutes ago, joigus said:

As said, and so far unanswered, the Lagrangian formalism makes it quite transparent that there can be no thrust for the COM system. It is true that the Lagrangian formalism can only be applied to conservative systems. But friction would only make it worse, not better, for the OP's claims.

You cannot ignore the accelerating mass transfer caused by the reactionless Euler force that is seen from the Inertial as a "real" but still reactionless force. Therefore, you are not using the right kind of the Lagrangian formalism.

28 minutes ago, joigus said:

Assuming there's no friction, any angular displacement would result in a linear displacement, depending on the pitch of the screw.

You are the first who clearly acknowledges how a linear actuator works. The next step is to acknowledge the rotating frame is an intrinsic part of the rotating frame. Acknowledging this is equal to the statement "rotating frame is significant to COM" (since a reactionless accelerating mass transfer is taking place).

Edited October 11, 2020 by John2020

[Ghideon]

1 hour ago, John2020 said:

That would be possible when there wouldn't be an accelerating mass m_T. I am expecting the behavior you just mentioned to be negligible in Fig.1-Upper because the angular momentum of the device (Ideal Machine) is transferred to mass m_T. 

Right at the start when the engine is started there is no momentum yet but there are internal forces acting. The engine is trying to begin to turn the screw using force. Due to Newton there is a reaction force acting on parts of the engine. What happens with that force? The engine (and device it is mounted to) will be forced to rotate. 

 

47 minutes ago, joigus said:

That's exactly what I think. There will also be a push and pull effect along the axial direction, to be studied in terms of action and reaction, if you will. Again: no overall momentum. Even though the detailed analysis would be quite involved. Assuming there's no friction, any angular displacement would result in a linear displacement, depending on the pitch of the screw.

As said, and so far unanswered, the Lagrangian formalism makes it quite transparent that there can be no thrust for the COM system. It is true that the Lagrangian formalism can only be applied to conservative systems. But friction would only make it worse, not better, for the OP's claims.

Thanks for checking my answer. I agree with your analysis and that the details are involved. Side note: I partially base my analysis on practical experiences from power tools such as drills and on the behaviour of accelerating motorbike with flat twin engine with Longitudinal mounting.    

Edited October 11, 2020 by Ghideon
format & added a comment to Joigus. Spelling

[John2020]

12 minutes ago, Ghideon said:

What happens with that force? The engine (and device frame) will be forced to rotate. 

Ideally, we assume the momentum of the translation screw is entirely converted into drive nut (mass m_T) displacement. In this case the rotation of the device is negligible. This is what I also I assume (an ideal situation) in my paper.

Edited October 11, 2020 by John2020

[Ghideon]

1 minute ago, John2020 said:

Ideally, we assume the momentum of the translation screw is entirely converted into drive nut (mass m_T) displacement. In this case the rotation of the device is negligible. 

Initially, right at the start, there is zero momentum and some force acting to turn the screw. That force has an* equal and opposite force in the engine even in ideal circumstances.

 

*) Or several action reaction pairs depending on the internal electrical construction of the engine, but that is not necessary to introduce at this time. It will not add any clarity.

[John2020]

2 minutes ago, Ghideon said:

That force has an* equal and opposite force in the engine even in ideal circumstances.

If the above statement is related to real forces along the axis of rotation of the translation screw then, you are wrong because there is none. That would be evident only in Fig.1-Lower but not in Fig.1-Upper.

[Ghideon]

38 minutes ago, John2020 said:

If the above statement is related to real forces along the axis of rotation of the translation screw then, you are wrong because there is none. That would be evident only in Fig.1-Lower but not in Fig.1-Upper.

I am talking abut the force that applies the torque that starts to rotate the screw. And the equal and opposite force on the engine (and its mount points); an action-reaction pair. Unless the mass of the screw is zero there must be a force to begin the rotation, a force perpendicular to the screw.

[John2020]

30 minutes ago, Ghideon said:

I am talking abut the force that applies the torque that starts to rotate the screw. And the equal and opposite force on the engine (and its mount points); an action-reaction pair. Unless the mass of the screw is zero there must be a force to begin the rotation, a force perpendicular to the screw.

As i said I am addressing an ideal situation as exactly is presented in Fig.1-Upper. In my first post I mentioned the system is internally powered. We don't have to address motors and power in this analysis (it is not the purpose of this paper). As you see in Fig.1-Upper there is a couple F_A and F_A' (perpendicular to the screw) that applies upon the screw provided by the motor in the housing. I brought this subject for discussion to see if it may work in principle. Again, the rotational energy of the screw is assumed to be entirely converted to mass m_T kinetic energy. It is a theoretical study of an ideal system. That is all we need to know as starting point to address this ideal system.

So, for me it remains the following statements:to be addressed:

1.Inertial frame: There is no Euler force

2.Rotating frame: There is Euler force

3.Inertial frame:The rotating frame is an intrinsic part of the inertial frame that means the whole is considered as a single Inertial frame

4.Rotating frame: Euler force is the cause behind the acceleration of mass m_T without causing a reaction upon the rest of the inertial frame

5.Inertial frame: Due to (3) and (4) the COM of the Inertial frame will change along with its momentum

6.Inertial frame: It will start to accelerated because of (5)  

Is there any objection on the above?

The above statements address this ideal situation. An alternative construction that has no contact forces is the magnetic lead screw (contactless lead screw). See the YouTube video below:

 

Edited October 11, 2020 by John2020