Hans Christian Ørsted

Today's little stamp features the work of Hans Christian Ørsted, who discovered and formulated our initial understanding of how an electrical current flowing through a wire creates a magnetic field laying the foundation for modern electromagnetism.

The old centimetre–gram–second system has units of Orsted named after him, but they vanished in the modern SI system: the oersted is defined as a dyne per unit pole (old style), thus the oersted is 1000/4π amperes per meter, in terms of modern SI units.

I think this stamp is from 1977, can't remember much about that year other than the silver busses and being given an ugly mug in primary school.

Another long day spinning plates, but I've made progress on some fronts and managed to keep the plates spinning!