Human Magnetoreception

Human Magnetoreception

- Richard de Grasse

LIKE MANY OFFSHORE SAILORS ON WATCH AT NIGHT, I DWELL on all kinds of things. On clear nights in the Northern Hemisphere, I consistently look up at the North Star, roughly gauge its angle and orientation above the dark horizon and compare it with our GPS latitude. A quick look at the magnetic steering compass reassures me we’re on course. It’s not that I don’t trust our GPS or our compass; the North Star reminds me of an earlier time in life when, with an accurate clock, sextant, tables and all, I navigated our sloop safely on long passages without electronics. As we drift away from traditional offshore navigation skills, I’m reminded that perhaps there was a time in history when human beings were able to determine direction without the aid of a magnetic compass.

Man has long been amazed at animal and bird navigation. How do they migrate and find their way for thousands of miles? Think about the size of hummingbird and butterfly brains. Carrier pigeons are particularly amazing — they can find their way back to their home roost from faraway places they had never previously visited.