What's that
Maybe this photo needs some explanation. It's a magnet held up close to the diffraction pattern caused when electrons pass through a carbon film. You know, one of those Teltron tubes you're never allowed to touch. The interesting thing here is how the magnetic field focuses the electron beam into a point. This is the principle of the electron microscope, electrons are used instead of light and magnetic and electric fields are used instead of lenses. Worth mentioning how using electrons with their shorter wavelength leads to higher resolution than light.