Explore Light: Sources, Shadows, and Reflection!

Light is something you can see all around you. It comes from sources like the sun, a lamp, or a flashlight. You already know about the sun from studying Day and Night, Sun, Moon, and Stars the sun is our biggest and most important light source!

Light travels in straight lines. It moves very fast and helps you see everything around you.

A light source is anything that makes its own light. Some light sources are found in nature. Others are made by people.

Natural light sources include the sun, stars, and even fireflies! Fireflies make light inside their own bodies using a special chemical reaction. Made-by-people light sources include lamps, flashlights, and candles.

When you are in a dark room, you need a light source like a flashlight or lamp to help you see. Without a light source, everything looks dark!

A shadow forms when an object blocks light. Light travels in straight lines and cannot bend around solid objects. When your hand blocks a flashlight, a dark shape appears on the wall that is your shadow!

You can make shadow puppets by placing your hand between a lamp and a wall. The shadow copies the shape of whatever is blocking the light.

Shadows also change size depending on where the light is. In the morning, when the sun is low in the sky, your shadow is very long. When the sun is high above you at midday, your shadow is short. You can observe this yourself when playing outside!

Reflection happens when light bounces off a surface. When you shine a flashlight at a wall, the light bounces back that is reflection! This is why you can see the bright spot on the wall.

Smooth and shiny surfaces reflect light very well. Moonlight is actually sunlight that reflects off the surface of the moon and travels to your eyes. The moon does not make its own light it reflects the sun's light!

Some materials let light pass through them. These are called transparent materials. Clear plastic wrap and glass windows are transparent you can see right through them!

Other materials block light completely. These are called opaque materials. Cardboard, wood, and your hand are opaque. When light hits an opaque object, it cannot pass through, so a shadow forms on the other side.

Light: Light is something that lets you see the world around you. It comes from sources like the sun, lamps, and flashlights.

Light Source: A light source is anything that makes its own light. The sun, a flashlight, a lamp, a candle, and fireflies are all light sources.

Shadow: A shadow is a dark shape that forms when an object blocks light. Your body makes a shadow when you stand in sunlight because your body blocks the light.

Reflection: Reflection is when light bounces off a surface. When you shine a flashlight at a mirror or wall, the light reflects back toward you.

Transparent: Transparent means light can pass through a material. Clear plastic wrap and glass are transparent materials.

Opaque: Opaque means light cannot pass through a material. Your hand, cardboard, and wood are opaque they block light and make shadows.

Echo: An echo is when sound bounces off a hard surface and comes back to your ears. You might hear an echo in a cave or a large empty room.

You can explore light at home! Shine a flashlight at a wall and put your hand in front of it. Watch the shadow your hand makes. Move your hand closer to the flashlight does the shadow get bigger or smaller?

Try shining a flashlight through clear plastic wrap and then through cardboard. Notice how transparent materials let light through, but opaque materials block it and make shadows. You can also explore Sun Movement and Daily Sun Patterns by watching how your shadow changes length throughout the day!

You have already learned some great things that help you understand light! From Day and Night, Sun, Moon, and Stars and Daily Patterns and Basic Observations of Sun and Moon Movement, you know that the sun gives us light during the day and the moon reflects light at night.

Your Observation Skills Using Senses to Observe and Describe help you notice how light looks and changes. You also used what you know about Material Properties Color, Texture, Hardness, and Flexibility to understand why some materials block light and others let it through.

Light is connected to many other topics you will explore! Sound Properties Volume, Pitch, and Vibration is studied alongside light because both light and sound are forms of energy that travel and can bounce off surfaces.

You will also explore Sun Movement and Daily Sun Patterns to see how the sun's position changes your shadow length throughout the day. Moon Phases and Basic Moon Observations connects to light because the moon reflects sunlight to create moonlight.

Learning about Physical Properties and Observable Characteristics of Materials helps you understand which materials are transparent or opaque. You will also discover how Plant Responses Reactions to Light, Water, and Touch shows that plants need light to grow and survive.

This topic prepares you for exciting future learning! You will go on to study Light Energy Sources and Properties, Sound Energy Vibration and Sound, and Heat Energy Sources and Transfer. All of these topics build on what you learn about light today!