If you flatten out some magnetic putty, place your credit card magnet tape down on it for a minute, would it leave a magnetic impression you could pick up by placing blank magnetic tape at the same location on the putty?
Could there be an instance where you need to reverse the magnetic pole on a rod or something and sticking a glob of magnetic putty on it would do the trick?
Okay, so the first thing to get out of the way is that "magnetic putty" is not in and of itself a magnet - it's (almost always) silly putty mixed with extremely fine particles of something ferric, usually iron oxide powder. By itself, it won't pick up metal objects through magnetism.
However, like many ferric materials, it can be made temporarily magnetic by the application of a strong magnetic field - e.g. with a strong neodymium magnet as in the above gif. It's not very good at retaining magnetism for very long, but in the same way that you can turn a needle into a compass, you can make magnetic putty roll ball bearings on the other side of a (thin) sheet of glass.
Magnetic strips on cards, OTOH, are not a misnomer - they have ferromagnetic particles embedded in them, meaning that once they've had a magnetic field applied to them, they retain their magnetism (more or less - there are always exceptions and caveats). (Hey, remember audio cassettes? Same deal). However, it's a very weak magnetic field. If you smooshed a credit card onto flattened out, unmagnetised magnetic putty, my gut feeling is that the magnetic strip would not be powerful enough to measurably alter the field of the putty - certainly not with sufficient resolution to be read back by anything but the most sensitive of instruments. (If you did the same with pre-magnetised putty, you'd probably just mess up the strip). Think of it this way - you can't copy a credit card strip by putting magnetic tape against the card itself, so magnetic putty won't make that process work any better.
Your second question is rather more intriguing - presumably a blob of magnetised magnetic putty would have reasonably well defined poles (although - would it? What happens if you smoosh it up? I might have to try to get hold of some to experiment with...) Anyway, assuming poles, I imagine that you could stick it, pole reversed, to one end of a bar magnet, the natural stickiness would hold it there, and you would have - very temporarily - a monopole of sorts. After that, I'm guessing that the ferric particles in the putty would attempt to re-align themselves with the field of the bar magnet, and after a while you'd be back to a standard bar magnet with a blob of putty on one end. However, this is all guesswork - I reckon the best thing to do would be to get hold of some magnetic putty and some magnets - and a timelapse camera - and do some experimenting.
Anyway, if you've read through all that, here's another video of magnetic putty being weird and cool (http://vimeo.com/63773788).
You're right. ^_^ The very weak magnetic signature on the tape would be insufficient to move or charge the iron particles in the putty, or at least not enough to be detectable by a blank tape.
I'm assuming that in the gif in the OP, after completely engulfing the magnet, the exterior surface of the putty have the opposite polarity of that part of the magnet it was touching. Or maybe not quite... we've seen this before in the form of iron filings on a sheet of paper over a bar magnet. Oh crap, I'm an idiot. It's like sticking two bar magnets in a straight line. The exterior surface of the putty will have the same pole at the same place as the magnet it has engulfed. So I still don't see a practical use for it, except making neat gifs. Maybe iron filings in a blob of transparent silicone gel would make a neat variation on the OP.
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(no subject)
Date: 2014-01-21 08:45 pm (UTC)(no subject)
Date: 2014-01-22 03:47 pm (UTC)(no subject)
Date: 2014-01-21 08:59 pm (UTC)Could there be an instance where you need to reverse the magnetic pole on a rod or something and sticking a glob of magnetic putty on it would do the trick?
(no subject)
Date: 2014-01-22 01:36 pm (UTC)However, like many ferric materials, it can be made temporarily magnetic by the application of a strong magnetic field - e.g. with a strong neodymium magnet as in the above gif.
It's not very good at retaining magnetism for very long, but in the same way that you can turn a needle into a compass, you can make magnetic putty roll ball bearings on the other side of a (thin) sheet of glass.
Magnetic strips on cards, OTOH, are not a misnomer - they have ferromagnetic particles embedded in them, meaning that once they've had a magnetic field applied to them, they retain their magnetism (more or less - there are always exceptions and caveats). (Hey, remember audio cassettes? Same deal).
However, it's a very weak magnetic field. If you smooshed a credit card onto flattened out, unmagnetised magnetic putty, my gut feeling is that the magnetic strip would not be powerful enough to measurably alter the field of the putty - certainly not with sufficient resolution to be read back by anything but the most sensitive of instruments.
(If you did the same with pre-magnetised putty, you'd probably just mess up the strip).
Think of it this way - you can't copy a credit card strip by putting magnetic tape against the card itself, so magnetic putty won't make that process work any better.
Your second question is rather more intriguing - presumably a blob of magnetised magnetic putty would have reasonably well defined poles (although - would it? What happens if you smoosh it up? I might have to try to get hold of some to experiment with...) Anyway, assuming poles, I imagine that you could stick it, pole reversed, to one end of a bar magnet, the natural stickiness would hold it there, and you would have - very temporarily - a monopole of sorts.
After that, I'm guessing that the ferric particles in the putty would attempt to re-align themselves with the field of the bar magnet, and after a while you'd be back to a standard bar magnet with a blob of putty on one end.
However, this is all guesswork - I reckon the best thing to do would be to get hold of some magnetic putty and some magnets - and a timelapse camera - and do some experimenting.
Anyway, if you've read through all that, here's another video of magnetic putty being weird and cool (http://vimeo.com/63773788).
(no subject)
Date: 2014-01-22 03:03 pm (UTC)I'm assuming that in the gif in the OP, after completely engulfing the magnet, the exterior surface of the putty have the opposite polarity of that part of the magnet it was touching. Or maybe not quite... we've seen this before in the form of iron filings on a sheet of paper over a bar magnet. Oh crap, I'm an idiot. It's like sticking two bar magnets in a straight line. The exterior surface of the putty will have the same pole at the same place as the magnet it has engulfed. So I still don't see a practical use for it, except making neat gifs. Maybe iron filings in a blob of transparent silicone gel would make a neat variation on the OP.
(no subject)
Date: 2014-01-22 03:46 pm (UTC)(no subject)
Date: 2014-01-21 10:17 pm (UTC)(no subject)
Date: 2014-01-26 03:00 pm (UTC)http://en.wikipedia.org/wiki/Grey_goo