During 2019, I have enjoyed the privilege of being part of the international advisory board for Physics Toolbox AR. Trying out the app, I have been fascinated by the possibilities to catch invisible magnetic field lines and discovering the direction of north by maximising the horizontal component of the arrows.
Travelling to Australia, via Singapore, opened new possibilities to discern how the magnetic field varies with location, and even catch a midday shadow pointing to the north. (And, of course, visiting amusement parks, as well as discussing jerk and other aspects of motion with David Eager’s group at UTS)
So for this solstice post, when the sun is about 10° from zenit in Sydney, but only reaching about 10° over the horizon in this part of the world, I share a few magnetic field screen shots. And wish I could also share some of the rain expected for Christmas eve with NSW and QLD, where it would be needed much more.
PS: No rabbits in this post, but some marsupials illustrating the motion in Enterprise, to facilitate the analysis of data from Lunapark in Melbourne. http://tivoli.fysik.org/english/attractions/enterprise/rotation/