[paul cotter (OP)]

Increasingly these days when I make a point on any subject I get a reply which consists of computer generated claptrap rather than a reasoned argument from a thinking conscious entity. I find this infuriating, maybe i'm just too old.

[alancalverd]

I am not programmed to respond to this question.

You may find reasoned arguments in the works of Plato, Einstein, and Marx, all of whom were considered at some time to be thinking conscious entities.

My extensive research suggests that Hamdani Yusuf has tried many times to define a conscious entity without success.

[paul cotter (OP)]

Thanks Alan, I was beginning to think I was on my own with this line of thinking. However Plato, Einstein, Aristotle, etc are all dead, who can I debate with?  I should have specified that it is not just with this forum, it is occurring everywhere I go. On a different forum I had to put a poster on ignore after he repeatedly posted reams of rubbish from bOng co-pilot, despite my request for person to person discourse only.

[paul cotter (OP)]

To me it's bong. The discussion was about possible exemptions to the conservation of momentum because of the finite speed of em propogation.

[Halc]

On a different forum I had to put a poster on ignore after he repeatedly posted reams of rubbish from bOng co-pilot, despite my request for person to person discourse only.

A supposedly bannable offense on several sites, but it's not going to happen here since, well, the entire mod staff being made entities, and not famous ones either.

The discussion was about possible exemptions to the conservation of momentum because of the finite speed of em propogation

That can be an interesting discussion. Don't know the scenario specifics, but my gut feel is that no exception can be identified, leaving one to explain different times of accelerations of separated objects from one frame to the next.

I here got into a pretty heated investigation into angular momentum conservation due to acceleration of spinning things, which have frame dependent centers of gravity. Ouch. I think bOng would have a low probability of producing a good answer to that one.


In the end, AI (real AI) is going to outdo us, and your best conversations (such as the one you want with Einstein or somebody) will be with the artificial thing. I don't think the chatbots can do that since they don't surpass anything, just sort of average it all out, which only works well if the consensus matches what the bulk of the training material says. How does a chat bot weed out the true crap when it finds so much of it in its training material?

[alancalverd]

Judging from the response to reply #1 above, I seem to have cracked the Turing Test and provided a human output indistinguishable for the useless crap that comes out of a computer!

Does anyone know how to turn off Bing's copilot?  It is utterly infuriating to have to scroll through AI-curated garbage to get to a useful search result.

[Eternal Student]

Hi.

         A spinning magnet - that can be interesting.   Indeed we had some discussion here (TNS forum) about a year ago.   You ( @paul cotter ) contributed to that old discussion but it was a long time ago.   I'm going to recap some of it.

       In general, a thing that is rotating should just keep rotating at the same rate, that's basic angular momentum conservation.   However, in outer space that doesn't seem to be what happens....    well... at least not if the spinning thing is actually a magnet.    In that situation it does seem that the object emits e-m radiation and MUST eventually stop spinning.

      Let's put conservation of momentum and angular momentum to one side for a moment.    If a spinning magnet emits e-m radiation then it is losing energy.   Energy conservation MUST apply.    If energy is being emitted or lost from the spinning object then it came from somewhere.   Either the spinning object is losing some mass over time, or else it is losing kinetic energy by slowing down its rate of spin.    It doesn't seem that a lot of mass is being lost, so the object must be slowing down its rate of rotation even though there is no obvious source of external torque being applied to the object.

     A long time ago, I started writing a new forum post based on this - but it became too long and had to be split into many parts.    In the end, I decided it was a monologue rather than a discussion so I never actually posted it.

   (Part II) had much of the mathematics in it.   Not a lot of that displays well now that LaTEX markup isn't available.     In words, it showed that the far field produced by a spinning magnetic dipole has the right characteristics to be considered as e-m radiation.        "Does a spinning magnet in space emit e-m radiation" --->  yes, it does.

    (Part III)  was based on an objection that @alancalverd raised in the (very old) original forum thread concerning the notion that the spinning object would ever slow down.   Where is the torque coming from to slow the magnet down if it's in outer space?     How is angular momentum conserved?   etc.
    The answer mainly seems to be that the e-m radiation that is emitted will be circularly polarised.   This allows the e-m radiation itself to have or "carry away" some angular momentum.   Well.... that explains "where" the angular momentum has gone but it still doesn't explain the source or cause of any actual torque acting on the spinning object.
      The torque acting on the spinning magnet seems to arise by consideration of the near field (near to the dipole object) as opposed to the far field approximation.   The mathematics here is just too complicated (for me anyway) and the other references I chased up seem to use only numerical (computational) approximations instead of finding exact analytical solutions.   In spirit, it seems that the near field changes at a rate slightly slower than the dipole is rotating,  so that the B field in the local space differs from the magnetisation, M vector, within the object itself.   As such the B field pulls on the magnetised object slightly and effectively puts a drag or retarding torque on it.   So, let's re-phrase this because it's quite weird when you think about it.......   What exerts a torque on the spinning magnet in free space?  Well... it seems that space does or whatever it is that we recognise as the B field in space.  Space isn't exactly "nothing", it has B fields in it.    The spinning object will spin at the speed it wants to spin, of course, and the Magnetisation vector M of that object should change at that rate - however space a few centimetres away cannot instantly change its B field when the magnetised object has moved.   The maximum propagation speed of a new B field is c,  so the B field just a small distance away is still the old B field.    This is a very simplified and wordy rather than mathematical version of what appears to happen but I hope it makes some sense and provides the gist of what seems to be going on.    It raises a number of other questions... space doesn't seem to be just empty space, it's almost as if the B fields in it are something tangible - but that's probably a whole other thread and not something we need to consider here.

You mentioned the following (which is why this example is relevant):
 

The discussion was about possible exemptions to the conservation of momentum because of the finite speed of em propogation.

     The spinning magnet in free space seems to be an example where instead of being a problem that may break the principle of conservation of (angular) momentum,  the finite speed of waves propagating through the E and B fields is actually NECESSARY, indeed it is ABSOLUTELY ESSENTIAL to maintain the principle of conservation of angular momentum.   It is the (tiny) delay between the magnetisation vector of the magnet changing its orientation and the changing of the B fields in nearby space that puts the retarding torque on the spinning magnet.   So, a magnet spinning in free space will slow down and eventually stop spinning and no laws or principles of conservation are violated.

Best Wishes.

[paul cotter (OP)]

Now we are digressing into physics- that's perfectly fine with me, I enjoy it. I will try to put in words what an acquaintance of mine(not the blocked individual) argues on this subject, he believes there can be violations of conservation in certain conditions.

[paul cotter (OP)]

I will try to convey the argument in question and hope I can do it justice. When we strike a ball with a bat we assume contact but at the atomic level this is not what happens. The repulsion of electrostatic fields actually transmits the force between the two objects in any apparent contact. Em fields have finite speed and this means there is a time lag between action and reaction although in almost all cases this will not be detectable. The next bit of his argument I don't get: he says that if the field is changing during such an interaction the action and reaction will not be equal and hence the conservation of momentum will be violated. My counter argument is that em fields carry momentum and thus Emmy Noether need not be bothered. At this point in the discussion bong co-pilot reared it's ugly head and I dropped out. If this thread needs to be split now, i'm fine with that.

[Halc]

I usually stay away from electrical topics since I'd probably get the magnetism parts wrong. I am not, for instance, qualified to critique the post done by E-S above.  But this situation is pretty basic.

Em fields have finite speed and this means there is a time lag between action and reaction although in almost all cases this will not be detectable.

Fields are by definition everywhere and don't 'go' anywhere. Changes to the field do travel, and yes, at c.  All this is true to everything from gravity to the strong force.

So there is no action/reacton going on here. There is say two similarly charged objects moving towards each other. There is always a force between them, so at no point does an 'action' by one of them commence. But the force grows as they approach, and maybe, due to the speed of the field change, the force between them may be less when they're X-distance apart than the force that would be between them at the same distance, but they're relatively stationary. This is due to the change of the field not getting to either of them yet. So still balanced forces, but not the same force if they were not approaching.

There is no cause/effect distinction. The situation is symmetrical so the ball acts on the bat as much as the bat on the ball.


Now let's change frames and see what relativity of simultaneity says.
In one frame, the two objects (synced clocks actually) are identical and moving toward each other at the same speed. The symmetry means they must always be moving at the same speed. The net momentum is always zero in this frame. The acceleration of each is continuously going up until the point of closest approach.  So lets consider this approach from a different frame.

From some different frame, the left object is say momentarily stationary, and accelerating to the left.  The right object, in that frame, is simultaneously accelerating less since from its perspective, the separation of the objects is greater. The time on the right clock is less than the time on the left one.  Is this a problem?  If it's accelerating less, it first appears that momentum of the system is not conserved, but momentum under relativity is γmv, and since the right mass is moving, momentum is exactly conserved in this case as well.

he says that if the field is changing during such an interaction the action and reaction will not be equal and hence the conservation of momentum will be violated.

That statement is wrong just for calling out a nonexistent action-reaction relationship.  The field change is entirely symmetrical in the frame where the interacting identical charges (almost 'touching' electrons say) have a net momentum of zero.

My counter argument is that em fields carry momentum

Here's where I get shaky since it gets into quantum mechanics and force carrier particles and charges that don't have measured locations. I'm not sufficiently knowledgeable to comment about such things. The post by ES does very much imply that say spinning magnets (even orbiting masses) radiate away energy and angular momentum, but I'm not sure if any of that is applicable to a standard bat/ball collision. My reasoning above is classical, not quantum.

If this thread needs to be split now, i'm fine with that.

I can do that, or re-title the thing (and perhaps move it) to reflect its changed purpose. Let me know what you'd like.

[paul cotter (OP)]

Leave it for the moment, I am trying to get the proponent of these ideas to make a post in "new theories". Since I do not fully understand the concept only confusion will result from me being a go-between. The original is in a near moribund forum called REVOLUTION GREEN which was concerned with energy and new ways to produce it. I don't recommend going there as it uses the "disqus" format which puts replies in random positions and one really has to read through mountains of rubbish to find a relevant post. Update: my acquaintance does not have the time to post on another forum and since I am not sufficiently well versed in his proposition the matter will end here. I should state that I think he is in error and that there are no violations of the conservation of momentum.