I have asked this question in multiple forums. These forums range from the 'bag of idiots and freaks' to a couple you have never heard about and probably never will.
I believe I have the answer but this answer requires raising a root math hypothesis to proof level. I don't like the idea of giving Euclidean math any more foundation than it has. It may also require relating a rather disliked physics effect to magnetism. Nuff said about that happening ;)
The answer may not be as simple as you think.
Set yourself up for a very complicated experiment. This experiment requires a non-ferrous coffee can, partially filled with fine sand and a magnet (try a cylindrical or disk shaped one).
Identify each pole with a different color mark from the center of the pole to the outer diameter, in a straight line.
Hold the magnet about eye level and drop it in the can of sand.
Two things should happen that become apparent after a few 'magnet droppings' ( new term for this ;D )
What are they and why do you think they happen?
If you don't wish to bother with this experiment don't bother asking me about it.
No interest?
Somebody has interest. The question is always deleted on Yahoo or Answers.com. MIT says the falling magnet is no different than any other falling object. Berkely asked me to not post this or a related question again.
Quote from: WaveWatcher on 2010.11.04, 10:34:18
No interest?
Somebody has interest. The question is always deleted on Yahoo or Answers.com. MIT says the falling magnet is no different than any other falling object. Berkely asked me to not post this or a related question again.
I will try this test this weekend with a plastic Folgers coffee can and sand.
The sand is to prevent bounce or damage to the magnet. The container is not important as long as it provides enough area to hit and doesn't attract to the magnet.
so, you have to be able to "see" how the magnet lands in the sand. OK
Quote from: WaveWatcher on 2010.11.04, 16:34:06
The sand is to prevent bounce or damage to the magnet. The container is not important as long as it provides enough area to hit and doesn't attract to the magnet.
WW, can you just confirm one thing. You say the experiment requires a non-ferrous can, does it matter if the can is made from an electrically conducting material such as aluminium... or not? It just seems odd to be referring to a coffee 'can' as we tend to get our coffee in glass jars, but this may just be just down to semantics. Thanks.
How about I just hold a compass and turn around?
Glass jars?
Avoid metal of any type, if possible. You may drop the magnet on a pillow, if you wish. The point of the sand is to prevent damage to the magnet and leave the magnet in the same orientation it had during the fall.
I suggest you mark the poles so you can tell them apart.
Since there is no aluminum or copper tube in this experiment there will be no measurable drag due to eddy current.
Since the Earth's magnetic field is so weak nothing should happen from this.
Dropping a magnet a few feet 'should' provide absolutely nothing new.
Maybe it will do nothing interesting. If so, please send your latitude via PM.
;D
Hmmm....
I had hoped someone would try this simple experiment.
My last attempt for a real answer resulted in a childish explanation of how a compass works. It was not even realted to the question >:(
One would think the same effect making airplane magnetic compasses useless during certain maneuvers would give the question credibility. :(
All I want to know is: What Law of Physics dictates that a magnetic dipole must align itself perpendicular to the ambient magnetic field when it travels radially to that ambient field and why is the alignment always polarized the same way regardless of magnet shape?
The best answer I have received is: "Your question does not warrant our time".
The answer must be common and obvious. So, what is the answer?
Anyone?
(I'll have to sketch this out to see if this makes any sense and possibly delete or edit this later.)
The magnet is moving, and this must change something or add other variables to the system. The fact that it is moving adds forces, for example.
Quote from: WaveWatcher on 2010.11.05, 02:24:47
Since the Earth's magnetic field is so weak nothing should happen from this.
Dropping a magnet a few feet 'should' provide absolutely nothing new.
It depends on the shape of the magnet.
I got some Neodymium cubes that align with the earths field in a strong way.
THis is in horizontal rotation so i suppose if i drop it it will always land facing magnet north - earth north given enough distance to fall.
:)
The shape of the magnet isn't much of a factor.
It is no factor at all over a fall of a few feet.
Air flow over the magnet seems to have no effect.
Until I hear a better explanation I am calling this 'Reverse Lorenz'.
When the magnet is falling, it is moving, the charges in motion produce a new current and associated forces in the magnet which alter the static forces.
I'll see what I can find to support this statement.
Quote from: WaveWatcher on 2010.12.07, 17:23:30
The shape of the magnet isn't much of a factor.
I have done these experiments and that is why i respond to you question.
Now you answer back that my finding must be wrong.....
The shape of the magnet is of GREAT IMPORTANCE as it determines how good the magnet can align with the earths magnetic field.
Ever seen a compass with a bar shaped needle?
Thats all i'm gonna say.
I'm not intrested in arguing over test results because someone thinks he know better.
:)
MC,
All I can tell you are the results of my experiments. If I had specially designed magnets I would probably prove you correct. I don't really care. The point is the magnet's polar axis aligns with the direction of travel, during a fall, 90 degrees away from where a motionless compass would point.
You may use a coin shaped magnet with the poles on the flat surfaces. The magnet will always land with a flat surface pointing down. Therefore, air resistance and concentration of magnetic field lines has very little, if anything to do with this. If you really had done the experiments, you would know this.
This has nothing to do with the simple function of a compass.
Quote from: WaveWatcher on 2010.12.07, 07:39:05
All I want to know is: What Law of Physics dictates that a magnetic dipole must align itself perpendicular to the ambient magnetic field when it travels radially to that ambient field and why is the alignment always polarized the same way regardless of magnet shape?
Is the north face up or down?
Have you tried it in the Southern Hemisphere?
I found a long time ago to let others find there own results on such a simple test, except when it is obvious they haven't performed it. In that case, I can at least tell who has performed the test. Not because I'm greedy or the results are that special but, because my results shouldn't have any effect upon other tests.
I have had some say their results in the Southern Hemisphere were flipped. No confirmation and I doubt that is true.
I haven't posted a video in a couple of years. Maybe it is time.
Quote from: WaveWatcher on 2010.12.07, 19:38:32
MC,
All I can tell you are the results of my experiments. If I had specially designed magnets I would probably prove you correct. I don't really care. The point is the magnet's polar axis aligns with the direction of travel, during a fall, 90 degrees away from where a motionless compass would point.
You may use a coin shaped magnet with the poles on the flat surfaces. The magnet will always land with a flat surface pointing down. Therefore, air resistance and concentration of magnetic field lines has very little, if anything to do with this. If you really had done the experiments, you would know this.
This has nothing to do with the simple function of a compass.
If your results differ from mine we have a problem don't we ?
I was talking about the shape of the magnet and the horizontal rotation of it while the magnet is falling, and the position it will take when landed in the sand.
You say:
The shape of the magnet isn't much of a factor.Which is not true, you can have shapes that react strongly to the earth's field and you can have shapes the react weakly to the earth's field.
You say:
Since the Earth's magnetic field is so weak nothing should happen from this.Which is simply not true it's quite strong actually.
Quote from: WaveWatcher on 2010.12.07, 19:38:32
If you really had done the experiments, you would know this.
This has nothing to do with the simple function of a compass.
These are some bad...bad words.
Your not worth my time.
Quote from: Microcontroller on 2010.12.07, 20:55:57
If your results differ from mine we have a problem don't we ?
I was talking about the shape of the magnet and the horizontal rotation of it while the magnet is falling, and the position it will take when landed in the sand.
You say:
The shape of the magnet isn't much of a factor.
Which is not true, you can have shapes that react strongly to the earth's field and you can have shapes the react weakly to the earth's field.
The latter statement is true but the strength of the effect is to do with the size and density of the magnetic field, not the shape of the magnet.
Quote
You say:
Since the Earth's magnetic field is so weak nothing should happen from this.
Which is simply not true it's quite strong actually.
This was a statement made in advance of those thinking my tests were fake. Of course, the volume of the Earth's magnetic field means strength. That volume, indirectly, has a pronounced effect upon the results.
Never the less, my results indicate it isn't the reaction of the magnet's field to the Earth's magnetic field that matters.
A magnetic field is only a perception or view of something more fundamental. The only reason it is perceived is because the source is in relative motion to the viewer. When that relative motion ceases, so does the magnetic vector.
This is why a magnetic field can never be rotated about it's own axis.
Bad words?
You call me a liar and I posted the bad words?
Yes, our time discussing this has ended.
I'll share some thoughts on this issue, but I haven't done the tests. Shoot me if you must.
The Earth's magnetic field relative to an observer on the ground is very weak, horizontal, and more or less in a North-South alignment. It's also totally static.
WaveWatcher, you didn't make any comments about the orientation of the magnet when you drop it, if you unintentionally impart some spin or tumbling on the magnet when it leaves your fingers, the size and strength and shape of the magnet, etc. You leave a lot of variables open there. I realize you are probably implying that an average-sized magnet when dropped "normally" from eye-height will land every time like you stated, with it's magnetic axis perpendicular to the Earth's magnetic field and in an "up-down" or vertical orientation.
However, to be realistic, you would have to specify more information to make the test a bit more serious.
Nonetheless, let's look at what can we say about the test. To keep things simple, let's neglect air friction. Let's say it takes 1/3 of a second before the magnet hits the sand. So, in other words, you have a magnet in free-fall, and it's "weightless" for 1/3 of a second.
The magnet has a certain mass and various moments of inertia. The mass and the shape determine the moments of inertia. There is a rotational energy upon release that depends on what kind of rotation or tumbling that might have been imparted on it when it leaves the experimenter's hand. We also know that the magnet has a specific moment of inertia relative to the magnetic axis. The strength of the magnet itself will affect how much torque the Earth's magnetic field imparts on it.
So you can distill the problem down to this: You have a certain mass and shape of magnet that may be tumbling in the Earth's magnetic field. How does it land in the sand after 1/3 second?
Since we are neglecting air friction, let's also ignore the possible tumbling for a second. Now we are stripped down to the bare bones. What would happen in this case, assuming that the magnet's magnetic axis is not lined up with the Earth's magnetic field?
The answer is pretty simple. You have seen how a compass needle rocks back and forth. That's what the falling magnet wants to do, oscillate back and forth in the Earth's static magnetic field. A stronger magnet will make the oscillation frequency increase. A larger moment of inertia will make the oscillation frequency decrease. Then, you add the possible tumbling and then it gets complex because the tumbling is changing the torque on the magnet due to the Earth's magnetic field.
So when I factor in all of the things above, I can't explain why WaveWatcher always sees the magnet fall with the same orientation. We know that the magnet wants to oscillate about the the axis of the horizontal magnetic field of the Earth. If left for enough time the oscillation would decay and the magnet would end up lined up with the Earth's magnetic field, not at right angles to the field. I can only guess that WaveWatcher is having some kind of coincidence happening when he does his tests.
MileHigh
Quote from: MileHigh on 2010.12.07, 22:21:23
I can't explain why WaveWatcher always sees the magnet fall with the same orientation.
Thats because he didn't do the experiment and i did.
I know it turns while it's falling.
Quote from: Microcontroller on 2010.12.07, 22:36:47
Thats because he didn't do the experiment and i did.
I know it turns while it's falling.
Why does it turn while it's falling?
While the topic at hand is itself very interesting,
this discussion has developed a certain "strangeness"
which is reminiscent of other forums where
head games, high emotions and silliness abounds.
I was hopefully expecting evidence of greater maturity
from the "experts." I well understand we all have our
"moments" and our "territory" and our "honor" but,
really, isn't some of the commentary a bit juvenile?
Where is Spock when he's needed?
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.
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
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 :)
WaveWatcher:
QuoteDoes 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!
Quote1. 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
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 :(
Have you done a sanity check to see if any conductive object will rotate like your magnets?
Quote from: Grumpy on 2010.12.09, 15:24:50
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.
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.
Quote from: szaxx on 2010.12.09, 20:20:58
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