How does a neon sign work?

   A neon light is something like a fluorescent light. Neon signs are made of glass tubes shaped into words and decorations. When you push a button, the words light up — red, blue, green. The light seems to swirl around inside the tubes. But where does it come from? There is no wire running through the tube as there is in regular electric light bulbs.
   The light comes from a gas with which the tube is filled. When electricity goes through this gas, it glows very brightly. A gas called neon gives off a reddish glow, and that is where the name neon light came from. Other gases make lights that are blue or yellow. Yellow light in a blue glass tube looks green. The movement that you see in the tube comes from the gas swirling around.
   It takes very little electricity to make the neon tubes light up, and that is why they are used for huge signs.