Optical phenomena in nature

Optical phenomena are abundant in nature. Light sources all around: the sun, stars, lightning, the Aurora, sprites etc. These light sources are all based on plasmas: ionized gases. When electrons are accelerated in an electrical field, they can get enough energy to excite atoms and molecules, which then emit photons. The trajectories of electrons and cosmic radiation are altered if magnetic fields are present. This is visible as the moving light patterns near the earth\\\'s magnetic poles. Thermal effect cause discharges in the atmosphere to contract into lighting strikes. In this lecture we will demonstrate, by performing gas discharge physics experiments in the lecture room, the processes that lead to excitation, contraction, resonance, de-mixing and moving under the influence of magnetic fields.