Discussion in 'Physics & Math' started by Q-reeus, Apr 2, 2013.
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Hi, finnaly got threw all 16 pages of this post, wich was one of the more intresting reads in a while. Thought i'd comment it, by giving a big salute to RJ for his experiment and trails.
Kudos, great post.
Educational as well.
I salute you for going through all 16 pages. Please Register or Log in to view the hidden image!
That takes dedication and perseverance, especially for something as trivial as this. Please Register or Log in to view the hidden image!
Given that you contributed absolutely nothing , I don't see what entitles you to characterize as "trivial".
What I meant was, most newcomers would not consider this topic important enough to warrant reading through all 16 pages.
That's why I jokingly saluted Engell79
Although he enjoyed reading our chit chat, he's still a hell lot more patient than me. Please Register or Log in to view the hidden image!
UPDATE: OK, I suspect some of you are going to have a "forehead slap moment" like I did after about 20 seconds into this video. It is possible that Nordberg is not a charlatan, nor has he discovered new Physics; a third possibility exists which I hadn't considered. (Youtube says the video will be uploaded in 30 minutes so this link might not work for a bit...)
The magnets in the compasses affect each other. This is why my first attempt with a single hand-held magnet showed no "mysterious phenomena", but Nordberg's experiment did: he used TWO compasses. This fact was indirectly alluded to when observers rightly pointed out that his compasses were not in perfect alignment (in fact they were almost in opposite alignment). You can see in my video that when the compasses are in this arrangement they do in fact deflect in opposite directions...but it has nothing to do with copper spheres!
Regarding our bet, Q-reeus, I'm conceding on it. I'm not sure that the deflection is identical with and without the sphere based solely on this experiment (it doesn't help that I apparently ran the current in the opposite direction on my setup with the straight-through wire) but I'm willing to accept standard theory. Again, if you want to send me your account info to firstname.lastname@example.org I'll send you $50. This was fun!
Hmmm, very interesting. I still don't understand why Nordberg's two compasses initially pointed in opposite directions. Your test with two compasses had them pointing in the same direction, and so did your test with three compasses. What am I missing here? Are the magnets in Nordberg's compasses just a lot stronger?
Did you watch the video? It has to do with the strength of the magnets in the compasses and their proximity. In my video the first, third and fifth compasses are far enough apart not to interfere with each other, while introducing the second and fourth ones causes the "phenomenon"
One view only? That's got to be mine lol.
You're the only viewer that matters, Tashja! Please Register or Log in to view the hidden image!
Yes, I watched it. When you had 5 compasses, there was interference between them. When you had only 2 or 3 compasses, (farther apart than the 5), you did not get interference. However, Mr. Nordberg only has two compasses, and yet he is getting the same kind of interference that you got with 5. So, either his compasses much stronger magnetically, or they are in closer proximity than yours. It's hard to tell from his video if the scale of everything is the same as yours, so I can't tell if it is the proximity, or the strength of the compasses. Either way, you did an excellent job of sleuthing out the real "phenomenon".
Eureka! Please Register or Log in to view the hidden image!
I didn't know those compasses could affect each other so strongly. Still, Nordberg should've realized his needles were pointing in opposite directions.
Okay Q-reeus, I'm gonna test the equivalence of sphere and wire more rigorously.
And RJ, you could get this for your son. Get him interested in particle physics. Please Register or Log in to view the hidden image!
Yep. Either Nordberg's compasses are pretty strong, or they are not as far apart as they seem to be in his video. What a silly mistake for him to make. (Assuming he did not know this was happening.)
An interesting demo there RJB. It's hard ahead of time to accurately anticipate the effects of mutual interaction of such stacked compasses. Qualitatively it makes sense that in the absence of any external aligning field, such stacked compasses would align anti-parallel one after the other, as that will minimize potential energy. That is clearly evident at around the 0:58 minute mark for the 5 closely stacked compasses when no current was flowing. Earth's field is evidently weaker than the inter-compass fields and cannot break the anti-parallel tendency at that spacing. The opposite deflections with current on is harder to account for. Azimuthal B field from current in sphere might be expected to just induce a uniform shift in anti-parallel alignment. Key to it is probably the impulsive nature at switch-on - there is an overswing past equilibrium point and a delicately balanced metastable range of anti-parallel stability is breached. Hand-wavy, but I'm not going to attempt some full analysis.
With three compasses this situation has reversed and earth's field now dominates over anti-parallel tendency - as evident at around 2 minute mark. Deflections are consistent with standard theory. Similarly and even more so for two compasses later on.
And I still believe Nordberg is a charlatan given his sphere was much larger than yours, with only two compasses used and much further apart. The initial misalignment of his two looked to be about 60 degrees, and given your experience, very unlikely indeed this was just mutual interaction. Have to suspect some other influence not evident in his vid. Just possibly he made no allowance for direction of earth's field, compasses were much stronger than yours (hence that much stronger mutual interaction), and that explained the ~ 60 degree misalignment, but again, with such large spacing of just two compasses, it is imo a highly charitable explanation. [I see Neddy Bate has made the same observation in #311]
[Edit: Way back I suggested those black stubs sticking out of his column of steel spheres may have been ferrous and that was causing funny deflections. But further, if his steel spheres are ferromagnetic, not non-magnetic stainless steel, each will act as a magnetic dipole source under influence of both earth's and wire/sphere's B field. This may just account for funny results. Hard to see how Nordberg could be so dull as to place copper sphere so close to that adjacent column of steel spheres when running tests. Maybe not so much dull as cunningly exploiting an accidental effect. We may never know the real story, for what that matters.]
Either way, his 'fusion dream' is just that - a dream.
I'll be in touch, and glad you could see it as having been fun! And more than that, a learning experience. Please Register or Log in to view the hidden image!
You're welcome to do so, but I guess you won't want to be placing any bets - right?
Why not? How about 30 bucks?
I'm not feeling too rich. Please Register or Log in to view the hidden image!
Ha ha. You will be feeling that much less rich if taking up the bet. Maxwell's equations just work. Anyway, I'll see it as you 'paying the bet virtually' just in your time and labor doing the check. Go to it!Please Register or Log in to view the hidden image!
thanks! Though I still don't have time now, it'll be a while.
A very good analysis. RJB and eram (if he ever does anything) can clean up the experiment by:
1. using one compass only and moving it between the "shelves" aligned vertically
2. stopping the nonsense with "pulsing" the current and allowing it to settle (this will take care of the transitory effects and allow a proper readout of the compass heading)
Hey, I brought all this up in the first place.
Thanks for the advice, nice guy. Please Register or Log in to view the hidden image! I'll take the necessary precautions.
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