Having just looked at Eric's cartoons (see "other chatter") and in particular the cartoon about compasses it occured to me, in my usual clueless way: Why can't a compass be made to compensate for the deviation of true north and magnetic north?
okenest:
I mean if you're in the UK and true north is say 5 degrees (I'm not sure of the exact figure) to the right of where the needle is pointing couldn't a compass needle be offset by those degrees so it's pointing in the right direction to start with?
The more I think about it the more worms are spilling out of the can here. :theyareon
Maybe the answer is: If you're at zero longtitude i.e. the UK this side of the globe and true north would 5 degrees to the right of where the needle's pointing, am I correct in thinking that if you're 180 degrees the otherside of the world (mid Pacific) true north would it then 5 degrees to the left of where the needle's pointing. Yes?
Have I just answered my own question?
It helps if you have an orange slightly tilted in your hands to figure this one out.
Then if that's the case compasses could only be manufactured and used in specific countries.
Ahaaa! Would a compass for Antarctica point downwards?
Feel free to start hurling the stones at me for my blissful, childlike ignorance. I'm wearing my best Kevlar codpiece in anticipation.
okenest:
I mean if you're in the UK and true north is say 5 degrees (I'm not sure of the exact figure) to the right of where the needle is pointing couldn't a compass needle be offset by those degrees so it's pointing in the right direction to start with?
The more I think about it the more worms are spilling out of the can here. :theyareon
Maybe the answer is: If you're at zero longtitude i.e. the UK this side of the globe and true north would 5 degrees to the right of where the needle's pointing, am I correct in thinking that if you're 180 degrees the otherside of the world (mid Pacific) true north would it then 5 degrees to the left of where the needle's pointing. Yes?
Have I just answered my own question?
It helps if you have an orange slightly tilted in your hands to figure this one out.
Then if that's the case compasses could only be manufactured and used in specific countries.
Ahaaa! Would a compass for Antarctica point downwards?
Feel free to start hurling the stones at me for my blissful, childlike ignorance. I'm wearing my best Kevlar codpiece in anticipation.