Hello, Magnetic North
A while back, I heard this very interesting Guardian podcast on the magnetic north pole. In case you’re wondering, “magnetic north” refers to wherever the compass points. As opposed to “geographic north”, which is the top point of the axis around which the earth rotates. Edmund Halley convinced the British Navy to fund his idea of plotting points on the globe by comparing the deviation between magnetic north and geographic north. The obvious use of this was in sea navigation. In theory, that was a good idea. In practice, it didn’t work. Why? Because the data was collected over a few years. Trying to combine data collected in Year 1 with that from, say, Year 3 led to all kinds of weird errors! This may “sound like a failure of epic proportions” but it led to a major scientific finding. The errors led to the realization that the magnetic north moves continuously, ergo data from different times wasn’t consistent! Today, we know the extent of the movement over the last few cen...