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
6 Light normally travels in a straight line However light moves at different speeds through hot air and cold air This causes refraction As the path of light from an object gets bent it changes where we see the object The bent light may make us see the image of a real object above or below where the object actually exists Mirages are illusions not hallucinations A hallucination is when the brain senses something that does not really exist A hallucination is com pletely imagined by the brain An illusion is different It is something that Refraction makes this straw appear bent at the surface of this drink
7 looks or seems different from what it is but it is a real image that can be seen and even photographed The brain simply understands the illusion of a mirage image differently from how it really exists The words mirage and mirror look similar because they’re related Why do you think these two words are related THINK ABOUT IT When light rays are bent in unexpected ways the brain can mis understand them and see an object differently from how it truly exists
