What is Light?There are many sources of

light!

SOLAR ECLIPSE

Do you know some examples of light?

Light sources (something that makes light)

Energy and Light Energy: the ability to do work

Light is ENERGY we can SEE

LIGHT ENERGY can change into HEAT ENERGY which can be used for work.

Light From Nature Natural Light:

Light from nature What can you think of?

The SUN! Lights our world and warms it We could not exist without the sun

(plants, cold, darkness)

The Sun The Sun is a star!

It’s the closest one to us so we get most of our light and heat from the Sun and not other stars (which are too far away!)

How important is the sun really?

Bill Nye and Solar Power

We see the sun everyday and we know it’s a big star with lots of energy but how much energy does it really have?

Solar Magnifier Video

The Moon Sometimes at night, the moon helps us

see. BUT the moon doesn’t make light The Sun’s light bounces off the

moon and makes it look like the moon is shining.

More Natural Light

Natural Light Natural light is really important to

humans But we can’t control them

We can’t turn the Sun on and off when we want to

Some of the animals that we saw before use bioluminescence to survive (communication, attract food)

Artificial Light A long time ago, humans only had

natural light How would their lives be different?

Artificial Light: Fire Humans learned how to control natural

light sources They found out how to make fire!

They used fire to keep warm, cook with and also do things after the Sun went down

Fire People learned they could burn other

things than wood to make light Examples?

Wax – Candles Oil – Lamps Chemicals - Sparklers

Artificial Light Artificial: Made by humans Artificial Light: Light made by humans

Most are made by electricity This is another type of energy

Artificial light is easy to control because they can be turned on and off with a switch

Bouncing Light? We talked about sunlight bouncing off

the moon Artificial light bounces too! The reason we see road signs is because

light from the car or streetlights bounces off the sign!

$ The Costs $ Natural Light is always free! Artificial Light always costs money!

Buying lamps, electricity, oil, batteries, flashlights

Even candles, sparklers and reflective clothing

We should conserve money and energy by shutting off artificial lights when we can!

OPEN A WINDOW!

Natural Light Artificial Light