UKC

Ages ago (March?) someone had a threadabout a compass mysteriosly changing polarity: it indicated due south as due north. There were varioustheories as to what could have caused it, one concerned shop anti-theft devices, but no clear answer was found.
I thought the anti-theft devices theory far-fetched, as I thought the fields they produced would be tiny.
Just read in New Scientist that they expose five year olds (whose heads are at the most vulnerable height) to twice the recommended max level.
So is this what b*ggered the compass?
And, as an aside, has anyone thought about the effect on unborn babies?

In reply to illkate: As a geology student, I have been taught that every few million years the poles reverse, according to scientists who study paleomagnetism. It probably wasn't this though.

In reply to illkate:The original question was mine. An this explains everything, my little-un was about 4-5 at the time. Also like a magnet or the pole she believes everything revolves around her or should be attracted to her or indeed repelled. She climbed the Ben with me on Thursday in the pouring rain and as a precaution I laid a string trail to find the way of the summit. AS you can see this was a complete success and Id recommend this method to all parents of this age. Leave your compass at home strings much better. (guess who is child minding this weekend )

In reply to illkate: God bless you! For years, what I and several ex-friends had been attributing to my appalling map-reading/navigational skills (e.g. as a scoutmaster I've lost several cub scout groups in quicksand, over precipices) was really persistent reversals of polarity. So Dave, Geoff, and Thumper (the red setter)...if you can hear me from beyond the grave (?)...it wasn't my fault ! Ah, the guilt has lifted !

In reply to Sp:

I doubt it, cos had it been, if i remember my geology lessons right, our summers would now be winter and vice versa!!

john

In reply to illkate:

If you give me a week or so I'll tell ya....we got told a similar story by mountaineering 'aquaintence' of ours..happened on glacier somewhere in D.N.P, caused no end of hassles....i'll get the story from him.

I don't now about effect on unborn children, but am looking into it.

In reply to illkate:
Has happened to me on the Cairngorm plateau in quite a bit of cloud, my dad took bearing and started descending into Loch Avon basin (heading for ski car park). After 5ish mins, thought this seemed wrong, so tried again with my compass and we were going 180 degrees the wrong direction. Embarassed father thinks it had something to do with his ice axe - this happened to anyone else?

In reply to Stephen: I'm going to try and find the old thread. It had happened to several people, and no-onecould come up with a convincing explanation for it. Putting a compass near a magnet, even a strong one, doen't do it, but electromagnetic fields might, I gather.

In reply to everyone: the original thread is in the archives. It's called
180 degree error

the anti theft thing could be it, but more likely is the following:

you know the things that the anti theft doors things detect? those pesky magnetic coils? well, the device which deactivates them (so you don't bleep at the door) is a massive magnet. the posh ones send a large blast of electro-magnetism out to destroy the coil. the chances are that some gimp tried to deactivate the compass's tag...and deactivated the compass instead.

In reply to Hindu: No sorry, the compass worked perfectly well one day, the next it had a 180 degree error and still has to this very day. The compass belongs to Stuart Wood. I put it down to the spontaneous development of a very dense gravitational field within the cerebral hemisphere of Barrow Man. Thus standing as contrary evidence to Contemporary evolutionary theory.

In reply to Ladyboy:
from recend studies barrow minds can simply reverse from normal to rather dim very quickly. there's no reason to suspect that compasses in the hands of such individuals won't be affected too.

and furthermore, this reverse has an evolutionary benifit. At the end of the night, when the pubs throw the punters out, violence ensues. those who attempt to think rationally in the few precious seconds before a bottle breaks over their head will get hit, whereas those who just stop all thought and fight are more likely to survive. on a day to day basis, inteligence is a huge benifit, but in some situations can lead to you not reproducing. therefore those who can think normally, and then switch off survive and reproduce. i have too much time on my hands.

In reply to Hindu: many years ago i had a Silva compass which pointed south,,newly bought, i took it back to the shop,who gave me the address of Silva,i remember their letter well after i complained "contrary to popular belief this is not due to us painting the wrong end of the needle red but due to the compass being exposed to a magnetic field and passed through it e.g.CAR DASHBOARD,,," i never could accept their response,,thankfully i wasnt on the Ben in winter when i realised i'd got a duff compass!

In reply to ulcer: Car dashboard!!! The compass in the original thread hadbeen left in the car. Errrrrr.......hang on, why don't we all have knackered compasses then? I tried to knacker mine with a very strong magnet, it didn't work. Maybe some compasses are too weakly magnetised by the makers, and get switched more easily?
Oh, and I agree with the theory that intelligence needs to be switched off in order for reproduction to take place, having got up early as sleeping squashed between two offspring is not my idea of fun

In reply to illkate: right so your saying the reason I got woken up this morning at 6.30 (can I get up dad) was because in the past I switched of my intelligence. My god that expains alot! I ve just removed the Dash board from the car and Im hanging my compass on the rear view mirror, no, no effect.
Hindu I believe recent forensic examination of Barrow man artifacts indicates an approx 22,000 reversal in Barrow mans social development, clearly a link with the wobble earth thing. Is there a correlation with Phizas new routing activity?

In reply to illkate: Forget compasses and babies - my nads are at that height!!

In reply to jimbo: You bosting Jimbo?