Make: Technology on Your Time Volume 08

Citizen ScientistHOMEBREW MAGNETOMETER

BUILD A TORSION BALANCE TO MEASURE TINY CHANGES IN THE EARTH’S MAGNETIC FIELD.

By Dr. Shawn

MOST OF US ONLY THINK ABOUT THE Earth’s magnetism when we need to find our way in the wilderness. When you look at a compass, the Earth’s magnetic field appears to be a steady guide. But in reality, the magnetic field fluctuates in response to all sorts of aetheric influences, some of which come from beyond our world.

For example, the sun boils off a steady stream of electrons and protons into outer space, and whenever a large solar prominence erupts from the surface that’s facing us, a hot torrent of charged particles rushes outward and eventually slams into our cold and relatively quiescent ionosphere. The collision ...