The gas used in neon signs is neon itself, which is a noble gas that glows brightly when an electric current passes through it. Neon was discovered in 1898 by William Ramsay and Morris Travers. When contained within glass tubes and energized, neon emits a distinct bright reddish-orange light, commonly associated with advertising signs. Although neon is the primary gas, other noble gases like argon may be used to produce different colors when combined with phosphor coatings. Neon signs are renowned for their vibrant colors and artistic signage, making them iconic in nightlife and entertainment districts worldwide.