What Is Light Light is everywhere Every morning sunlight fills the sky and at night we switch on the electric lights in our homes Light shines from our cell phones and TVs and from our streets and our cities Light for Life Humans plants and animals all need light to live Without it we wouldn’t be able to see Even worse we wouldn’t have any food and there would be no life on Earth 쑼 Early morning sunlight streams through the trees in a park in central India The Sun is our main source of natural light 4
DAY AND NIGHT The place where you live cannot be in daylight all of the time because Earth spins When your part of the world is turned away from the Sun it is nighttime See for yourself how night and day happen You will need a ball or globe a sticker a flashlight or small lamp 1 Place the sticker on the ball to mark where you live 2 Darken the room as much as you can Shine the light at the ball to act as the Sun 3 Slowly spin the ball around Your home moves into the light daytime then away from the light nighttime 1 2 3 쑿 Divers use flashlights to explore a flooded cave system in Mexico Light Energy Light is a strange and amazing form of energy like heat electricity and sound What is light exactly and where does it come from How far and how fast does light travel How do our eyes see it and how do animals and plants use it You’ll find the answers to all these questions in this book 5
