Transcript What is Light? - WordPress.com

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 from nature
What can you think of?
 The


Light:
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 $

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



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