TV watching in the 20th century involved looking down the barrel of an (electron) gun shooting the image onto a bulky screen, but 21st century plasma TVs bathe the viewer with millions of fluorescent lights. It seems like a solid image on a plasma screen, but it is actually millions of sealed voids called pixels. It takes more than 2 million for the coveted 1080i HDTV, but it’s pixel size, not the quantity, that changes with the screen size. Consider a multilayered sandwich. Each pixel is composed of red, green, blue and sometimes yellow phosphor-coated subpixels filled with neon, xenon and argon gas, backed by vertical strips of electrodes. These are covered over by a protective layer of magnesium oxide, horizontal strips of transparent display electrodes, insulation and finally the glass screen. The gases stay inert until the tv is turned on, then electricity excites the gas, turning it into plasma and causing it to emit ultraviolet light. This light reacts with the phosphors, releasing visible light. The onboard computer tweaks this reaction with an incredibly complicated split-second orchestra of electrical signals via electrodes, which alters the illumination of the pixels from a choice of over 16 million hues, creating a moving picture.