[bulent osman]

bulent osman  asked the Naked Scientists:
   
Hello and let me begin by saying what a wonderful team, what a wonderful production!

I don't listen to the radio show but catch it all via podcast, to which I have done twice. Yes I have circumnavigated the Naked Scientist twice. Do I hold the record I wonder?
 
I have a question. There was a film with Anthony Hopkins,to which the name escapes me, and he is lost in the wilds, killing 10 foot grizzly bears with a pen knife as you do.
 
So in a bid to find direction home he pulls out a pocket watch and proceeds to removing the hands of the clock face, places one on a leaf then finds a perfectly still patch of water to place the leaf upon. well the leaf very slowly turns presumably by the attraction of the poles on the metal hand. Would it work?

So I was about to ruin my grand dads gold pocket watch then remembered he didn't have one so I was thinking perhaps Dave had a pocket watch and could perform the experiment instead?
 
Thanks again guys for a truly wonderful show.
 
Best Regards
 
Bulent Osman
 
From Chislehurst Kent  (just in case I get a mention

What do you think?

[Bored chemist]

There's an easier way provided that the sun is shining and that you know which hemisphere you are in.

[RD]

Could magnetise a pin or needle to use as a compass needle using a magnet in earphones.
Or if you're living in the 1970's, a bit of video or audio tape will float on water and point North: no leaf required.

Perhaps we should start a MacGyver thread, here's one I MacGyvered earlier ...

It is just possible to record a heartbeat with this MP3 + Funnel combination ...

 [ You are not allowed to view attachments ]

Amplifying and filtering the recorded sound with software like Audacity (free) improves the audibility a lot...

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If you doctor is far away it would be possible to record the whistling chest sound using the above
type of apparatus and email the sound recording to him/her, (telemedicine style).

http://www.thenakedscientists.com/forum/index.php?topic=24326.msg264531#msg264531

BTW the Anthony Hopkins film with the bear was called "The Edge", (the bear was called Bart).

[lyner]

Or if you're living in the 1970's, a bit of video or audio tape will float on water and point North: no leaf required.

Presumably the end with "N" written on it would 'point North'?
I think what you mean is that it will always orientate itself in the same direction. You'd need to ascertain where North actually was, in order to use it later.

[RD]

Re original question:

I just remembered that metal can be magnetised by hammering, so the watch hand could be magnetic, (if iron).

http://www.wikihow.com/Magnetize-With-a-Hammer

[Bored chemist]

Another way to magnetise steel is to heat it above the Curie temperature then let it cool in a magnetic field.
Since the earth has a magnetic field it turns out that most mist of steel end up magnetised to some degree.

However, as I said, there's a way that doesn't involve invalidating the warranty on the watch.

[Nizzle]

If you have some basic orientation and astronomy skills, a watch is a compass.
Just look at what time it is, and look at the position of the sun during the day, or some constellation during the night.

[Bored chemist]

Nice point about the stars.
I noticed when I was in the Southern hemisphere that the Man in the Moon was "the wrong way up".
So, as long as I have enough time to observe the moon and the sun, I can find north with a watch