NATURE S MYSTERIES MRAGES AND OTHER MARVELS OF LIGHT AND AIR ARBRA PENI Britannica Educational Publishing IN ASSOCIATION WITH ROSEN EDUCATIONAL SERVICES
4 Imagine this story A lost traveler wanders through the desert It is hot and dry The traveler is very thirsty Then he sees a pool of water ahead He can’t believe it The trav eler runs forward and tries to jump into the pool But when he gets there the water dis appears There is just sand below him There was never any water An image of water in the desert that really isn’t there is one kind of mirage WHAT IS A MIRAGE Some deserts have real pools of water like this one but images of water in the desert are often mirages
5 Mirages appear in many forms A mirage is an image that looks real but is not truly there Mirages are caused by layers of air being at different temperatures and densities Cool air is denser than warm air These properties can make light bend as it passes through the different layers This bending called refraction creates images that trick your brain into believing an object is located where it is not Density has to do with how much of a substance is in a certain area Air is made of particles of gas Density of air means how tightly packed the particles of air are VOCABULARY The properties of the air in this desert cause the light to bend and form a mirage of a pool of water
