Magnetic North, or Not-So-NORTH!?
Apparently magnetic North is not static, it changes. Only now, this change is accelerating and it’s wreaking havoc with our navigational systems!
Does this mean our sundials are no longer accurate? I believe, because they are calibrated in accordance with geographic North (where all the longitudinal lines meet), rather than magnetic North, we’re OK! Although we did use compasses to try and find ‘true north’. I think our time pieces are alright, but our maps and compasses are all out of whack! I wouldn’t plan on any long-distance sea voyages without consulting an up-to-date adjustment.
Students use a protractor to determine the 40 degree angle of the gnomon (because New York City is due north approximately 40 degrees longitudinally).
It’s a Tankel, not a Timex!
tankelteach 