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Author Topic: Falling Magnet  (Read 13755 times)
Group: Guest
MH,

The 'self-orientation' is strong enough that any unintentional or intentional hand-added spin is overcome in the short fall.
The same magnet pole always faces 'up'. I suppose someone will really give one a rippin' twist before the fall and prove me wrong. I didn't see any point in exerting myself.

Since I am in the Northern Hemisphere, I could imagine the falling magnet's proximity to the Northern magnetic pole could cause the South pole of the magnet to tend pointing up as it fell. It doesn't.

On my first trial I assumed chance was playing a role so I simply dropped different styles, shapes and sizes of magnets while recording results. There was no need to be concerned with chance. There was no 'chance'. I have some large coin-shaped neo's that will orient themselves during a drop from knee level. (poles on the flat surfaces)

And yes, there is also spin, as I eluded to in the earlier posts on this thread.

I would like to obtain results from different locations. I know the results are repeatable in the central US, South Eastern GB, Mexico and Germany. I know because I performed each one. I was hoping to try in the Southern Hemisphere but my travels have ended for an unknown amount of time.

I have had reports that the results are reversed (which pole points up) south of the equator but I am very skeptical about those results.

I suppose that different latitudes may produce different results but that is a shot in the dark.

Basically, the falling magnet acts similar to a point charge moving through a magnetic field - except spin and vertical orientation are imparted instead of angular momentum.
 
This seems weird enough for me to keep asking the question. It also seems the more I ask the more abuse I receive.

I have a theory but the math doesn't prove it, yet.

Research indicates this action has been known since the mid 30's but was simply considered a nuisance by airplane pilots before more advanced equipment was invented. The explanations of causes were never proven with most attempts failing.

I'm only looking for a solid explanation of the effect. I do not claim discovery as that is asinine. The effect was discovered more than ten years before my birth.



   
Group: Guest
WaveWatcher:

I would be tempted to do it myself but I don't have anything handy.  The bottom line as far as I can see when I turn it into a "thought experiment" is that if you follow the magnet as it falls, it would simply want to wobble (a.k.a.; oscillate) back and forth in the Earth's magnetic field.  It's just a simple LC oscillator, with "C" being the moment of inertia of the magnet and "L" being the springiness/torque applied to the magnet by the external magnetic field.  I can't think of any logical reason for your observations.

Certainly what's critical is the frequency of the LC resonance, with mass/moment of inertia of the magnet and the strength of the magnet coming into play.  A large heavy magnet shouldn't really be affected at all.

As far as the Northern vs. Southern Hemisphere goes, I don't see it at all.  In both hemispheres you have almost the same set of conditions; a static horizontal parallel magnetic field in the same rough North/South alignment.  Let's assume that your positions in latitude on the two hemispheres are more or less equivalent.  The only major difference would be that the slight angles of inclination of the magnetic field would be opposite.  i.e.; in the Northern Hemisphere if the angle of inclination was downwards by five degrees when looking North, it would be upwards by five degrees when looking North in the Southern Hemisphere.  People seem to forget that the Earth's magnetic field at the surface of the Earth looks pretty much the same if you are in either Hemisphere.

MileHigh
   
Group: Guest
Yes. The LC type oscillation, magnetic declination and magnetic inclination have been considered.

In your thought experiment....

Does the magnet react differently between the states of 'motion with weightlessness' and 'weightless without motion'?

....

While suspended from a string, the magnet aligns itself with the Earth's magnetic field line - it acts like a compass showing declination and inclination.

While falling, the magnet aligns itself between 45 and 90 degrees of that same field line. I suspect a much longer fall will always result in 90 degrees to the field line.

The questions I am trying to answer are:

1. What is the mechanism for the difference in change intensity between the magnet with no motion (suspended) and motion (falling)?
2. Why does the magnet align with the geomagnetic filed line under no motion and anti-align under motion?

Correct answers for the above may force me to change my understanding of why the magnet spins about it's polar axis during the fall.

If I had a means to make magnetic bullets I would be on the firing range about now. Everyone else should have ran for cover  :)
   
Group: Guest
WaveWatcher:

Quote
Does the magnet react differently between the states of 'motion with weightlessness' and 'weightless without motion'?

Indeed, this is related to a heated debate that crops up on the forums.  It goes like, "If I rotate a magnet on its magnetic axis, can this be "seen" by a pick-up coil?"  The answer to that one is no, with the caveat that no magnetic field is going to be perfectly symmetrical and there will be minor perturbations that will be sensed by the pick-up coil.  The main point being that even if the magnetic field is "rotating" the only thing the coil can see is changing magnetic flux with respect to time.   A symmetrical "rotating" magnetic field on the magnetic field's axis looks the same as a stationary magnetic field.

So the answer to your question is no, the magnet will not react differently.  It's falling through a magnetic field that is unchanging, like horizontal filaments all parallel to each other.

And I realize that you suspect something is going on there because of your observations.  The problem is that you are up against 150+ years of working with and testing magnetic fields, and the chances of any related effects from falling through a uniform horizontal field going unnoticed are realistically zero.

None the less, you have a conundrum!

Quote
1. What is the mechanism for the difference in change intensity between the magnet with no motion (suspended) and motion (falling)?
2. Why does the magnet align with the geomagnetic filed line under no motion and anti-align under motion?

I kind of answered your questions above.  I am also still suspecting mechanical inertia is the dominant game player here.  For example, it would be hard to measure, but if you could measure the wobble oscillation frequency for one of your magnets and the time it takes to fall then you would have an idea about how much of an angle the magnet could deflect during the fall.  Suspending the magnet by a thread to measure the oscillation frequency would not work because the thread itself is a torsion spring.

I am not sure how far you want to go but I hope that you are having fun with the challenge!

MileHigh

P.S.:  This experiment makes me think of something that has always fascinated me - knife throwing.  An expert knife thrower can throw a knife at a target from any distance and 99.99% of the time the knife will hit the target blade-first and stick.  We probably all have had that experience as kids throwing knives and somehow you just "feel" it and you get the knife to land properly 90% or more of the time, from any throwing distance also.  What's going on there???!!!!  lol
   
Group: Guest
The only way I can be sure of said motions is to use a high speed camera - better - two  :)

Since every cute little anomaly before wound up as explainable by current rules, sometimes more than one together, I'm not willing to invest much cash on this problem.

Using strings, I have been able to demonstrate velocity has a multiplying effect upon the reorientation. The strings were Superglued at opposite sides of the 'equator' (not going to use a term like 'BLOTCHED wall' here  :o ). The magnet was suspended in a small picture frame and the whole mess move up and down. Slow vertical movement and the strings (torsion springs) don't allow pole over pole rotation. Fast movement - the magnet rotates against the string torsion.

I dropped the experiment because I could have had off-center strings causing false-positives.

I suppose I need to find a camera with a fast frame rate  :(

   

Group: Tinkerer
Hero Member
*****

Posts: 3948
tExB=qr
Have you done a sanity check to see if any conductive object will rotate like your magnets?
   
Group: Guest
Have you done a sanity check to see if any conductive object will rotate like your magnets?

I tried a ferrite antenna rod close to the size and shape of a magnet exhibiting this action. The weight was considerably less than the magnet. This effect wasn't shown.

I haven't seen a reason to try non magnetized metals. The weaker the magnetic field the less chance of seeing the action.


Electromagnet replacement?

No. I don't see a way to build a battery powered solenoid that will match the space, size and strength of a magnet without the chance of complicating matters.

A good variation of the test is when you include an non-metallic inclined surface. Let the magnet slide instead of fall.

With one pole against the surface the magnet will slide smoothly, just as expected.
With the other pole against the surface, and the right sliding angle/speed, the magnet will appear to tumble or jump off the surface. Then only change the magnet polarity and the magnet will just slide.

I doubt cardboard has metals of any consequence in it's makeup.
   
Sr. Member
****

Posts: 276
Hi,
A spherical neo in a larger diameter glass tube filled with wallpaper paste. Set your own variables with viscosity ......
Im sure the neo will be pole marked, removes sticky string theory lol.
Just a sensible suggestion for viewing any unexpected results relatively slowly.
Steve.
   
Group: Guest
Hi,
A spherical neo in a larger diameter glass tube filled with wallpaper paste. Set your own variables with viscosity ......
Im sure the neo will be pole marked, removes sticky string theory lol.
Just a sensible suggestion for viewing any unexpected results relatively slowly.
Steve.

Good idea!

My experiments are always kind of sticky, anyway  ;D
   
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