‘Possibly we have a sense called magnetoreception which lets us tune into the earth’s magnetic field and know where north is. Birds can do it…
There’s some scientific evidence from 2019 that humans can detect magnetic fields: when placing subjects in an isolation chamber, among many participants, changes in their brain waves correlated with changes in the magnetic field around them.
Humans are sensitive to polarised light… Polarised light is interesting because light across the sky is polarised in a particular pattern depending on the position of the sun. See: the Raleigh sky model…
It has been suggested that Vikings were able to navigate on the open sea in a similar fashion, using the birefringent crystal Iceland spar, which they called “sunstone”, to determine the orientation of the sky’s polarization. This would allow the navigator to locate the sun, even when it was obscured by cloud cover. An actual example of such a “sunstone” was found on a sunken (Tudor) ship dated 1592, in proximity to the ship’s navigational equipment.
So maybe we unconsciously tap into a natural ability to sense polarised light, which is to say a sense of where the sun is, and so end up with a sense of north?
Dogs tend to poop aligned north-south. It’s probably because they’re sensitive to the earth’s magnetic field rather than polarised light. How do the scientists know? Because during magnetic storms, dogs poop any which way….’
— Matt Webb via Interconnected