mirage

Mirage is an optical phenomenon produced by atmospheric refraction. Light rays bend as they pass through air layers with different temperatures and refractive indices, causing distant objects to appear displaced, elevated, or inverted. An inferior mirage occurs when hot air sits near the ground and light is refracted upward, creating the illusion of water on roads or pavements. A superior mirage forms when cooler air lies below warmer air, which can lift or distort objects beyond their true position. A more elaborate form, known as a Fata Morgana, produces multiple, stacked, and smeared images.

Mirages are common in deserts and over hot surfaces, but any place with strong temperature gradients can produce them, including coastal horizons. They are physical phenomena resulting from refraction rather than illusions of the mind; the light paths are real, though the image is not in the same location as the object.

Etymology and usage: The term mirage derives from French mirage, from Italian miraggio, from Latin mirari, meaning to wonder. In everyday language, mirage also denotes an unattainable or illusory goal.

Beyond the atmospheric phenomenon, Mirage is used as a proper noun in various contexts. The Mirage is a hotel and casino in Las Vegas. The name appears in film, music, and gaming, reflecting its metaphorical sense of ephemeral or illusory hope.