Well, there is scientific proof.
The direction of the polarity of iron in the earth crust is aligned with the magnetic field.
If you look at that alignment in a place that has been constant and relatively undisturbed you will see patterns of change in the rock. The patterns look like stripes.
This has been tested and proven on the crust on either side of the Atlantic Ridge.
What causes it was still unknown back in 1982 when I took my last geology course.
There is actually a scientific field dedicated to just these studies in stone.