Ghideon

Maybe we can start from the basics of classical mechanics? Do you know what conservation of momentum is? Do you accept it as a generally applicable principle? Can you make a picture and show the survey that contradicts me? That way we will clear up any misunderstandings.

The center of mass of the system will not move. The "system" in this case would be me and the other components mentioned. Momentum (linear and rotational) will be conserved.

Then there will be internal rotations in the system. Analogy: A car with an engine (spinning the cars wheels) will be able to move linearly along a road due to the interaction between car's rotating wheels and the road. A car in space, with no contact with ground, will not move, regardless of how many wheels there are, how they are oriented, or how fast they are spinning. The car will not be able to move its centre of mass. Period. You seem to argue in favour of a reaction-less drive. They do not exist according to mainstream science as far as I know so please provide supporting evidence.

Where did I clam that? You can not make a system move linear by having internal rotation. That should intuitively be easy to see knowing some basic mechanics. It can also be verified using math. Are you claiming that a closed system can propel itself by having internally rotating parts, not interacting with something external? Movements due to interactions with external forces, masses etc is of course another thing. But you have not asked about that.

You asked about forces that sums to zero. But for a system with internally moving parts momentum will be conserved. Rotation or linear does not matter. Would you like an explanation that contains momentum as well as forces? May I advice you to study the math that explains it all?

I could show, but a problem is that it requires math that you have said that you do not yet master. If I would take the time to write down the lagrangian of the specified system, resulting in differential equations predicting the motions, would you benefit from it? (Lagrangian mechanics is fun and interesting but not the topic of this thread) Instead I’ll try simplified explanation. Some notes: We do not have to do the calculations to predict the outcome on the system as a whole. Note that this explanation is extremely general. No matter what kind of contraption you come up with the following explanation should apply. Note that It applies to all forces, it is not limited to electromagnetism. Above is your system. I’ve drawn it in a blue box to highlight the boundaries. 1: According to the drawing there are no external forces pushing on the system. 2: The system is supposed to stay intact, you have not stated that it will break apart. 3: Pieces may move relative to one another but no piece will ever leave the system ad get ejected outside the rectangle. The above constraints means that we can apply F=ma to the complete set of things in the box. And since F=0 then a=0. There is no force and hence no acceleration. That the system does not accelerate means that whatever internal forces that we look at have to cancel. How? Because any force experienced by any piece or part of the system in the blue rectangle will cause an equal and opposite force on some other piece or part in the box. If the forces do not balance out internally then we would have some piece (lets call it P1) where there is a net force. A force F>0 on P1 means that according to F=ma P1 is accelerated. But what happens to the other piece (P2) in the system, experiencing the equal and opposite force? P2 will also accelerate according* to F=ma but in the other direction. The important thing is that the acceleration of the second piece P2 directed away from the first piece P1. In other words: if the internal forces does not balance it means that the system breaks apart. That does not match constraint 2. The above length reasoning can be stated mathematically, very generally applicable. I'll try an analogy using the https://en.wikipedia.org/wiki/Eiffel_Tower. AFAIK the tower remains stationary relative to earth. It does not take of as a rocket. That means that the total sum of forces on the tower is zero. If not, the tower would experience acceleration relative to earth. Now look at the internal forces. There are thousands of struts and bolts, calculating each and every force is possible but not an easy task. But we do not have to, to be able to predict the sum. We know the sum is zero since the tower is not accelerating. If we remove a strut, tighten a bolt or add some magnets or stuff in the tower's complicated structure it will never ever make the tower fly. F=0 for the tower whatever complicated rearrangement we ever try. What we can do is removing or adding stuff or shifting things internally so that some part(s) of the tower breaks. Then various parts will fall in various directions. But never ever will we be able to shift forces internally in the towers structure so that tower moves it’s center of mass and stays intact. Again this is all about classical mechanics. If we do the calculations in detail of your system and find some net force we know that the calculation is incorrect. The explanation is valid for low masses and low speeds, relativistic effects is not considered. I'll see what I can find. *) If the masses of the pieces P1 and P2 differ the magnitude of acceleration will differ.

Thanks for clarifying. Yes there will be force(s) on circle E and they can be calculated. And by changing the charges with correct timing you could generate rotation about points F and G. I believe this is well known facts in physics. And when calculating the sum of forces in the device, not E in isolation, the forces will cancel. Just to state the obvious, the device will not move anywhere. It may wobble or jump due to imbalance but the common center of mass will not move.

? You did not say anything about switching charges. Switching the charges makes the calculations you provided less correct. Maybe you could explain what you wish to achieve? Maybe a complete drawing, all time dependencies stated and math that matches that? Charges can be flipped and movement made to continue. Are you trying to show a basic electric motor?

Ok. The formulas seem a little off. The charged circles will move relative to one another if the beams are free to swing around. That means the distance between the charges will change. Since charges move there will not be one single "r" and the values of the different "r" will be time dependent. After some time I think the system will settle with charges D,A,E,B,C aligned horizontally. How is this related to the other stuff in the thread?

Agree. And I think we know the result already, internal forces will cancel and generate zero thrust. You mean that the triangle shape will accelerate upwards when electrons emitted at A and recovered at C?

I would have to see a picture, hard to visualize what you are proposing/asking. This is the first time in this thread electric fields are mentioned in this thread, I'm not able to find enough information to comment.

Not sure I understand what you try to show. Are you trying to show that the circulating electrons mass generates thrust? From what I see so far this is the only thing in the setup that could create (a tiny) thrust. Calculating the momentum of the lost mass gives the momentum of the rest of the system in the opposite direction.

It's been a (long) while since I studied electromagnetic field theory so my sources are of limited use. Depending on background additional studies of math may be required, for instance to calculate the effect of superimposed fields or charges distributed across surfaces or volumes. Basically it is a matter of describing the shape of the field(s) and apply the correct math. Depending on the shape and/or time dependencies the math may be very simple or really hard. The physics is well understood and documented in lots of books, typically with examples of linear or curved magnetic fields. A difference compared to what?

Clarification: by effects I specifically mean effects on momentum of the system. In reality, and more generally, losses due to heat or resistance or other from emitting electron at point A are not cancelled by receiving electrons at point C.

Hard to give a generally applicable answer, depends on directions and magnitudes. Calculations may be required. In a simple and static case I would add the vectors of the involved magnetic fields and then calculate the effects from the resulting field.

Angle does not matter. For any mass that is ejected and then returened the effects from ejection and collection will cancel.

Changing an angle between current and the magnetic fields may change the outcome when calculating the force. But the total momentum of cable + the core is conserved, the combined center of mass for cable and core will not move Maybe you could provide a picture?

Depends on what you wish to achieve. Propulsion of the system is not possible if the mass is recycled in the system.

I believe it matters since calculations will be different, the force is not constant. The blue cable will slide upwards, and after a short time slide out of the gap and experience a different magnetic field. You would have to calculate force as a function of time. That may be tricky (haven't tried yet). And it is correct, the core will be pushed down when the cable is pushed up. If there is a current in the blue wire I assume it is powered somehow and connected to something, affecting movements. But in an ideal situation we can choose to neglect that to simplify. Again, what will have a momentum? I guess you mean the blue cable? If so then yes (at least for a short while). The total momentum of cable + the core is conserved, the combined center of mass for cable and core will not move.

As far as I can tell mass is ejected and then returned to the system. Your drawing shows ejection of mass (electrons) at one point (A) and then the electrons are recovered at another point (B). Electrons seem to be circulating in the system.

AFAIK python does not make a copy of objects so TempList and List points to the same object. Operations on TempList affects the objects and List points to the same object. This operation: TempList = List[:] Creates a clone of the list so there are two independent objects in memory. When using primitive types such as integers or booleans python will make a copy. This behaveour of ”values” vs ”references” may differ from language to language. https://docs.python.org/3/faq/programming.html#how-do-i-copy-an-object-in-python

like an anchor prevents a ship from drifting away is probably a better analogy...

Ok! A note regering the assumption: To reduce the risk that there is a misunderstanding, exactly what is assumed ho have change of momentum? Is the blue circular cable free to slide upwards out of the gap or is the blue cable mounted solid and supposed to be staying in the gap?

You asked if your calculation is correct. I wanted to make sure that your calculation correctly expressed what you intended. Back to the calculation. Note that the current in the cable generates it's own magnetic field. But we can probably neglect that in this case unless you intend to have a large current and a weak magnetic field. And if you want to calculate the force on the cable due to the magnetic field then the E field can be neglected. If you know the dimensions it might be easier/more practical to use length and current instead of charge "q" and velocity "v". But that is just details, the formula seems ok for the force on the current carrying cable due to magnetic field. Incorrect. The purpose of the speculations section is "checking peoples work" or "have our idea checked". Unfortunately that means you are sometimes stuck with amateurs like me, the professionals seems not t be very interested. An alternative is to write a scientific paper and have it peer reviewed by professionals working for a journal.

Not sure about "anchor", intuitive answer is "no" but clarification might be needed. By "anchor" you mean can gyros be used to make it harder to move something, like an anchor prevents a shop from drifting away? Gyros are harder to rotate but not harder to move. Yes. One example is the Kepler spacecraft. What makes this interesting is that two of it's four gyros broke down and required a lot of investigations how to adjust observations according to that fact. That means that there is lots of documentation about the performance of the gyros, their issues and various attempts at workarounds. AFIK Kepler had four gyros (wikipedia/Reaction_wheel) and failure of two severely affected, but did not put an end to the mission to hunt for exo-planets. @Dave Wave here are some references that may be interesting from an engineering point of view: https://www.nasa.gov/feature/ames/kepler/nasa-ends-attempts-to-fully-recover-kepler-spacecraft-potential-new-missions-considered https://www.nasa.gov/content/kepler-mission-manager-update-preparing-for-recovery https://www.nasa.gov/content/ames/kepler-mission-manager-update-k2-has-been-approved A space based device to detect gravitational waves needs stability and gyroscopes are one option. But could the gyroscopes them self be used for more than stability? Interesting question that I do not have an opinion* at the moment. I think the question could be phrased like: does rotating gyros, when affected by a passing gravitational wave, add any value when trying to detect the wave? Does general relativity, when applied to rotating mass, make any predictions that would favour detections? I have no answer at this time but I find the question interesting. Other members will probably have answers. *) If I had to make an educated guess I would say "no, gyros does not add value regarding the detection except for stability". But that opinion has about zero scientific value.