Fascinating Facts About Light  Sir Isaac Newton discovered that white light forms when all the colors of the spectrum are mixed together.  A spectrum is produced when white light is broken into a band of different colors; red, orange, yellow, green, blue, indigo (bluish purple), and violet.

More Fascinating Facts About Light  Water droplets, bubbles, and other curved or angled surfaces bend, or refract, white light, separating the white light into bands of colors.

How Does White Light Travel?  Unlike sound, light waves travel in straight paths called rays.  Light waves do not need a medium through which to move.  Light moves in outer space.

How does white light travel?  Light travels in waves.  Compared to sound, light travels extremely fast.  It takes light from the sun less than 8½ minutes to travel 150 million kilometers to reach the Earth.

Reflection  When a wave hits an obstacle, such as a mirror, it bounces back.  This is called reflection.

Regular Reflection of Light Rays – Flat, Shiny Surface

Diffuse Reflection of Light Rays – Rough, Shiny Surface

Refraction  Light travels in straight paths until it hits an object then it can bend which is refraction.

Refraction  When a wave enters a new medium it changes speed.  Remember, the pencil in the glass of water.

Refraction Of Light Refraction is the bending of light as it passes from one transparent material to another.

White Light is made up of different colors!

White Light is made up of different colors!

By bending a white light wave through a prism, we can see the color spectrum: red, orange, yellow, green, blue, indigo, and violet.

How can we detect the visible spectrum?  A prism can be used to refract visible light.  When the different wavelengths of light in visible light pass through a prism, they are bent at different angles.  The colors of light we see are red, orange, yellow, green, blue, indigo, and violet.

What is white light?  Visible light appear colorless.  It is also known as white light.  In fact, it is made up of seven different colors: red, orange, yellow, green, blue, indigo, and violet.  Each color has a different wavelength and frequency.  Together they make up the visible light spectrum.

Colors  Light beams can be split apart.  The parts of white light are called colors.  We call the colors the “spectrum” of light.  What we see as white light is actually a mixture of all the colors of the rainbow – the full spectrum.

Frequency & Wavelength  For visible light, when the frequencies get lower, we see the light as red.  When the frequencies get higher, we see the light as violet.  That puts yellows and greens somewhere in the middle.  So, when you see red light, it’s traveling at the same speed right along with blue light, but red’s waves aren’t going up and down as fast.

Meet Roy G. Biv  Roy G. Biv is not a real person, but a trick for remembering the colors of light broken up by prisms.  Red  Orange  Yellow  Green  Blue  Indigo  Violet

What does the visible spectrum consist of?  The visible spectrum is white light that is a combination of several different wavelengths of light traveling together.  These wavelengths are represented by the colors red, orange, yellow, green, blue, indigo, and violet.  (ROY G. BIV).

Colors of the Rainbow  So the spectrum is all the colors of the rainbow. Okay, then what is a rainbow?  Instead of glass or prisms, rainbows come from raindrops that act like very small prisms.  The light goes in one side of the raindrop, bounces off the back side of the raindrop, and comes back out the front broken up into colors – just like a prism.

Colors of the Rainbow  To see a rainbow, your eyes, the rain, and the Sun have to be lined up just right.  You can also see a rainbow when you are near a waterfall or a lawn sprinkler.  They all work the same way; the water droplets break the light up into the spectrum of colors and reflect them toward your eyes.

Transparent  Transparent indicates the amount of light that passes through an object.  Substances through which light can pass fully, such as clear glass are said to be transparent.

Translucent  Translucent indicates the amount of light that passes through an object.  Substances which only let some light through are translucent.  Frosted glass is translucent.

Opaque  Opaque indicates the amount of light that passes through an object.  When light shines on an opaque object, the waves cannot pass through.

Concave Mirrors  Concave (caving in)

Convex Mirrors  Convex (bulging outward)

Tools That Use Light Microscope Telescope Periscope

Galileo Galilei  In 1609 Galileo heard about a new invention called a telescope. He decided to build a telescope and use it to look at the Universe.  Up until then people had only been able to guess what the Universe was, but Galileo was actually going to look at it and find out the truth.  With his telescope, he looked at the Milky Way and discovered that it was made up of millions of stars, each a different distance from Earth.  He used his telescope to study the stars, planets, and moons.

Anton van Leeuwenhoek  In the 1600’s a Dutch lens maker and cloth merchant, Anton van Leeuwenhoek made tools for studying science.  He made the first simple microscope.

Sir Isaac Newton  In the 1600’s Sir Isaac Newton first observed how a prism separates sunlight from the sun into a spectrum of many colors.  This happens because light travels at different wavelengths and bends at different angles to make different colors.