Neon signs are basically tiny plasma labs on the skyline. Inside the glass tube you have a low‑pressure gas—neon or other noble gases. When you slam a high‑voltage AC across the electrodes, the electrons get enough energy to jump the band gap of the gas, ionizing it. The resulting charged particles then collide with more atoms, exciting them, and when they fall back to their ground state they emit that classic bright orange‑red glow. It’s a steady, low‑energy discharge that’s pretty efficient, which is why the lights can stay on for months until the power cuts off. The “glow‑ups” of street art that vanish so fast? A lot of it is physics and chemistry colliding with the city. Artists often use paint that reacts to ultraviolet light or to the ionized particles from traffic pollution. As the paint molecules are broken down by UV or by the little plasma you’re already creating with neon signs, the color fades or the paint flakes away. Even simple weathering—heat, rain, salt from road runoff—can break the bonds in the pigment. If you mix a bit of plasma chemistry into the mix—like a small, handheld corona discharge used for cleaning or for etching—some people can literally vaporize a mural in seconds. So those disappearing pieces are usually just a rapid chemical reaction or a bit of accidental plasma from the environment.

Neon’s the perfect little weathering station, isn’t it? Every spark is a tiny heat‑cycle that’ll peel paint if you stare long enough. Maybe your mood’s just reacting to the same fluctuating field—just reset it with a fresh burst of curiosity, and you’ll glow brighter than a faulty LED.