Magnet Myths and Misconceptions

[MileHigh]

Tinman:

See the attached image.

When I said the field would be at the maximum intensity, I meant the field inside the bar magnet.  That where the text "Max" is in the attached image.  On either side of the maximum strength field inside the magnet, the field is essentially the same with the same direction.  Sorry for not being clear.

Look at the two red loops in the picture.  The blue lines represent the rotational axis for each loop.  When the upper loop rotates about its axis, there will be almost no EMF generated.   When the lower loop rotates, there will be EMF generated, showing that the field is present.

If you can imagine perfectly straight field lines, then when you put a rectangular piece of iron in that field there will be no attraction force pulling the magnet in any direction.  However, the iron will line up with the field just like an iron filing.  That's the iron "falling" into its state of lowest magnetic potential energy.  Forget about where the magnetic field is coming from, it's just a thought experiment.

When you put a piece of iron alongside the center of a long rectangular magnet, the same effect is happening where you don't feel any force on the iron piece.  Referencing the diagram, you have a magnetic field inside the bar magnet going from right to left.  That will not affect the piece of iron.  Outside the bar magnet you have a nearly straight unchanging magnetic field going from left to right.  The iron piece is in that nearly constant unchanging field and therefore there is no net force on the piece of iron. However, the lower red loop in the diagram when spinning proves that the magnetic field is there.

MileHigh

[MileHigh]

Chris and Tinman:

Please see the attached image.

The bulges and the cones are a result of the ferrofluid "falling" to the lowest possible state of magnetic potential energy.  There are gravitational effects and surface tension effects that also come into play.  The individual spikes are a result of a complicated quest for finding the lowest MPE.   I already linked to an excellent clip from the "Sixty Symbols" YouTube channel that explains this in more detail.

I have a feeling that for both of you this notion of "falling" into the state of lowest magnetic potential energy is a concept that is somewhat foreign to you.   When a piece of iron gets attracted to and sticks to the end of a bar magnet that's exactly what's happening.   When you bring a bar magnet close to a pile of free iron filings in dry air (not in an oil solution) you see exactly the same effect taking place.  You see the iron filings forming long spikes and tendrils.  If you don't understand this concept then please do your research online.

The thinner center "waist" in the middle between the bulges is primarily do to the fact that the ferrofluid is being pulled towards each pole.  As has already been described in my previous posting, there is a minimum of magnetic attraction in this zone.   So the ferrofluid is pulled toward each end, but the ferrofluid itself is "sticky" due to surface tension and you get the center "waist" as shown in the attached picture.

MileHigh

[MileHigh]

Chris:

Look at my yacht!   I get paid $450 USD per hour to debate with you!

MileHigh

[MileHigh]

Chris:

I am reposting this image because you seemingly ignored it.  MarkE had to remind you about what the viewing film is actually showing you.

I don't think I have ever seen a YouTube clip where someone uses magnetic viewing film and speaks intelligently about what it is showing them.  What I have seen are dozens of clips where people use the film and whatever pattern they are looking at is taken as "conformation" of what they are investigating.  They don't even know what they are looking at.

Come on people, surely you can do better than that.

MileHigh

[MarkE]

Why not find a pic of an actual Bloch wall kind of setup,, come on MH, you know what I mean,, 2 stacks of magnets barley pulled apart or not exactly lined up.

After you find that one, then look to find one that has a larger viewing window so that you can see the outside lines of force continue on with the normal path from long pole end to long pole end.

This is why I call this a local area effect,,  and all the pictures so far have shown this,, even the spin picture.

Why not?  Because a Bloch wall is a boundary between two unaligned magnetic domains.  The magnetic polarization rotates through the width of the Bloch wall.  In a permanent magnet, the vast majority of domains are aligned.  Therefore boundaries between unaligned domains are far and few between.  EMJUNKIE has been promotiong the completely nonsensical claim that at the center of a dipole magnet there is a Bloch wall.  He even offers the fantasy that these walls are easily seen in ferro fluid and magnetic paper demonstrations with bar magnets.