Everything you learned about magnetizing a needle is wrong.
Improvised needle compass science

Page two has some great info on magnetizing a needle using a AAA battery, insulated wire, and a drinking straw.

-Blast

Excellent info, thanks.

Good Article. At school aged about 12-13 we were taught how to improvise a compass in Physics class, some folks could even get the needle to float on the dish of water without the paper just using surface tension after magnetising the needle with some insulated coiled wire and a PP3 battery. We were also taught how to make a little electric motor from some magnets, insulted wire, cotton bobbin, battery (making the split ring commutator was always tricky though) etc.

Bear Grylls in his video should have validated his little experiment with a proper compass for the viewers as floating a needle using a dry leaf on water can point in the wrong direction due to wind shear on the leaf, the magnitisation force is very weak as so is not entirely reliable.

Rubbing the needle in the hair is probably just to degrease the needle so as to improve the water surface tension rather than the belief that it is actually magnetising the needle.

The rubbing method would work if when rubbing you heated the needle above the Curie point (about 750-800C for most stainless steels)

I liked the experiment.

While it is a bit off subject I rather liked the look of the wine glasses and lexan with the compas in the middle. would be an intresting center piece. sorry for the "Martha Stuart" home decorating interuption

Well, glad that myth was debunked, cuz I have no hair!!! I really didnt know any of that though...guess what I am doing this weekend???

I like his rigorous approach and am eager to duplicate his results. Wonder if there are other myths that need to be tested...

Well, a fun read. Wonder if IT is a true?

The only one that made sense to me when I was about ten was stroking the needle with a magnet several times in the same direction, and if you had trouble getting it to float, coat the needle with ear wax.

Even as a kid I could tell the difference between static and magnetism.

Sue

I'm still having a hard time with the "everything you read on the Internet isn't true" part.

Excellent post Sheriff Blast. Thanks.