A plasma globe or plasma lamp is a clear glass container filled with a mixture of various noble gases with a high-voltage electrode in the center of the container. When voltage is applied, a plasma is formed within the container. Plasma filaments extend from the inner electrode to the outer glass insulator, giving the appearance of multiple constant beams of colored light (see corona discharge and electric glow discharge). Plasma globes were popular as novelty items in the 1980s.The plasma lamp was invented by Nikola Tesla, during his experimentation with high-frequency currents in an evacuated glass tube for the purpose of studying high voltage phenomena. Tesla called his invention an "inert gas discharge tube". The modern plasma lamp design was developed by James Falk and MIT student Bill Parker.A crackle tube is a related device filled with phosphor-coated beads. Construction Although many variations exist, a plasma globe is usually a clear glass sphere filled with a mixture of various gases (most commonly neon, sometimes with other noble gases such as argon, xenon and krypton) at nearly atmospheric...