Magnetic field using horseshoe magnet, keeper and iron filings

[TheLewAdsProductions]

awesome video

[RimstarOrg]

@TheLewAdsProductions Thanks!

[kfor714]

Where did you buy that magnet? And what is the brand name of it?

[RimstarOrg]

@kfor714 I just confirmed with them. The manufacturer went out of business and they don't like the u-shaped magnets coming out of Asia so they no longer supply them. Sorry, I can't help. Try googling I guess.

[90degreeman]

Iron filings I think are not magnets...they don't attract to a piece of solid iron (that is not a magnet , those magnetic zones are not aligned and they cancel each other). Please correct me.

[RimstarOrg]

@90degreeman They become magnets when in a magnetic field. Look up Ferromagnetism on wikipedia. Take an iron coat hanger wire and put it in a magnetic field for a while so that it's length is lined up with one end facing the magnet's north pole and the other facing the south pole. Then put it near a compass or a needle hanging from a thread and you'll see it's a magnet. I made a horseshoe magnet this way. Make some filings from the iron and the filings behave the same.

[90degreeman]

@RimstarOrg Fantastic. Thank you for answering. The best thing about science is that it should be based on facts and scrutiny from all points of view. I appreciate you taking the time to enlighten. I looked up Ferromagnetism and your explanation makes sense. I learned something new today.

[RimstarOrg]

@90degreeman It's the least I can do to pay back for stuff I learned today, :)

[bizkit459]

but...if the south pole on a bar-magnet will repell a metal object..how come the south pole on the horseshoe-magnet attracts the metal "keeper" in the video??? i kno i sound stupid, i just cant get my head around it! lol

[RimstarOrg]

@bizkit459 I think your confusion lies in what you said here "if the south pole on a bar-magnet will repell a metal object". BOTH poles ATTRACT a metal object. Did I say it wrongly somewhere? If it was my last reply to you, the repulsion I was talking about was an example of what DOESN'T happen. You don't sound stupid; in fact you made a very smart observation about the keeper being like the iron filings. By the way, only metal objects that are ferromagnetic will behave this way.

[bizkit459]

can you explain to me...why BOTH poles on the magnet attract the filings??? when i try to understand it, i imagine one bar of the "horseshoe" attracting and the other end repelling the filings???

[RimstarOrg]

@bizkit459 Both legs are attracting opposite poles on each filing. The North leg attracts the South end of the filing and the South leg attracts the North end of the filing. See the video at around 1:19. For repulsion to happen the South end of the filing would have to be facing the South leg of the magnet or the North end would have to be facing the North leg. But as you can see around 1:19, neither of those are happening. Both are facing their opposites and opposite attract.

[ThePOKOkitty]

how do they work?

[RimstarOrg]

@ThePOKOkitty Putting it simply... Electrons are themselves tiny magnets. They have a north pole and a south pole. In a permanent magnet a large number of the electrons are all oriented the same way so that their individual magnetic fields all add up to a bigger one that we can play with like in this video. In a normal material the electrons are oriented in more-or-less random directions, so their individual magnetic fields don't add up and we don't get any bigger field to play with.

[field16]

Your video shows that you don't need fancy computer software to map magnetic field lines - you just need iron filings and plexiglass! You even got a limited 3D view when the filings stood up. I wonder what would happen if we stacked multiple layers of plexiglass spaced apart with their own iron filings on each layer? May be hard to see anything but just on the side view. Cool demonstration of the usually invisible magnetic force.

[RimstarOrg]

@field16 Yeah, I almost missed noticing the 3d effect. I also was thinking about how to span the gap 3d-wise but the legs are too far apart. (pause) So just did a quick try with two magnets with one of each's legs close together in attraction and a piece of cylindrical acrylic cut lengthwise to span the 2cm gap between legs. I sprinkled filings on the cylinder. It does work somewhat. I'll play further when I get a chance.

[trance183]

Awesome video!

[RimstarOrg]

@trance183 Thanks! Glad you liked it.