posted on Jul, 29 2012 @ 03:32 PM
reply to post by Lazarus Short
Lazarus, that is a slightly different matter.
Airport runways are named for their approximate compass orientation. A runway that ran east to west would be called runway 09 or runway 27 depending
upon which end you are approaching (090 degrees and 270 degrees, the last zero is dropped).
These designations are based upon magnetic compass headings, rather than true. The magnetic pole is some distance removed from the geographical pole
and is in constant motion. Currently it is over northern Canada, in several thousand years it could be over russia. The US will see greater change in
magnetic directions due to the proximity to the pole. Think about how the bearing to an object changes more quickly at closer distances.
Over time, that runwaymay need changing to 10/28.
I haven't researched it as such, it is part of my job. I'm a navigation officer on merchant ships. Part of my job is to take a gyro compass bearing
of the sun in order to compare the result against the true bearing of the sun as found through published tables and calculations.
Most gyro compasses are normally within 1 degree of the calculation. On an ocean-going ship, this is checked every four hours and recorded in a
logbook. Any larger difference is investigated as it means the compass is on the blink. A 10 degree change would be very quickly noticed by thousands
of navigation officers across the world and advisories would be issued in a notice to mariners.
I hope you don't take that as a criticism, our memory plays many tricks on us. Despite all the technology in the modern world, professional
navigators still make use of the ever reliable celestial sphere in order to do our jobs. If anything changes, we would be telling the world as it
would throw all our calculations out.