Where do Light Sources come from?
1.) Electric light bulb
2.) Candle Flame
3.) Sun and other stars
-
What is Light?
Light is a kind of energy that can move in waves and
it is made up of a flow of small particles of energy called
photons. A ray of light travels very fast. The speed of light
equals 300,000 km/second. Nothing else travels faster than
light, not even sound!
The white light from the Sun is made up of the seven colours
of the rainbow: red, orange, yellow, green, blue, indigo and
violet.
After a rain shower you can usually see a rainbow in the sky
if the sun is shining. A rainbow is formed by the refraction
of the sunlight in the droplets of water that are suspended in
the air for the rain shower. Think of the rain drops as prisms.
If our Earth did not have an atmosphere, the sky would be black
like outer space. We would be able to see stars in our daytime
like an astronaut sees stars in space.
We cannot see colors in the dark. What makes if possible
for us to see colored objects is white light made up of all colors.
Atmosphere – our Earth’s atmosphere
is made up of a transparent mixture of several gases surrounding
our planet and held by Earth’s gravity. The mixture of these
gases is known to us as air or oxygen. Our atmosphere protects
our life on planet Earth by absorbing the ultraviolet solar radiation
and reducing the temperature extremes for night and day.
What are the uses of Sun Light:
1.) For Energy
2.) For Warmth
3.) To see things
4.) To help things grow