“Down in the Hortobágy of mirages,” the popular song goes. But what is a mirage? It is an optical phenomenon that we can witness on hot summer days, usually between around 9 am and 4 pm. It can occur in any flat area where the lower air layer becomes very warm. Temperature increases from the top layers of the atmosphere toward the bottom. At the meeting point of two layers of air, having different temperatures and optically density, light rays from distant objects are reflected completely.
To quote the words of Mór Jókai, 19th-century Hungarian novelist: “…the mirage sometimes picks up the images of places below the horizon, which are not visible even with telescopes, and then it seems as if the Hortobágy were filled with towns, and on other occasions, we can see two herds grazing on top of each other….”