The SunThe Sun The sun is a star The sun is a star

(made of plasma).(made of plasma).

Many explosions Many explosions happen on the sun happen on the sun (like atomic bombs) (like atomic bombs) that create energy.that create energy.

This energy (called This energy (called radiationradiation) travels in ) travels in all directions.all directions.

How Does Energy Travel?How Does Energy Travel?

Energy travels in Energy travels in waves (like water).waves (like water).

The close waves are The close waves are STRONG.STRONG.

Waves that are far Waves that are far away are WEAK.away are WEAK.

Which Side is Stronger: Which Side is Stronger: Left or Right?Left or Right?

Electromagnetic RadiationElectromagnetic Radiation

The sun is so powerful that The sun is so powerful that it creates 7 different kinds it creates 7 different kinds of radiation.of radiation.

Some of this radiation is Some of this radiation is strong (waves close strong (waves close together); some of it is together); some of it is

weak (waves far apart).weak (waves far apart).

All the different kinds of All the different kinds of radiation is organized in an radiation is organized in an Electromagnetic Spectrum.Electromagnetic Spectrum.

Electromagnetic SpectrumElectromagnetic Spectrum

There are 7 kinds of radiation in the electromagnetic There are 7 kinds of radiation in the electromagnetic spectrum:spectrum: RadiowavesRadiowaves, , MicrowavesMicrowaves, , Infrared RadiationInfrared Radiation, ,

Visible LightVisible Light, , Ultraviolet RadiationUltraviolet Radiation, , X-RaysX-Rays, and , and Gamma RaysGamma Rays..

The Electromagnetic SpectrumThe Electromagnetic Spectrum RadiowavesRadiowaves – weak waves that give your radio or – weak waves that give your radio or

TV the energy to work. (can you see them?)TV the energy to work. (can you see them?)

MicrowavesMicrowaves - weak waves that can cook your - weak waves that can cook your food or used for cell phones and radar. (can food or used for cell phones and radar. (can you you see them?)see them?)

Infrared RadiationInfrared Radiation – weak waves coming from – weak waves coming from something that is something that is hothot. (can you see them?). (can you see them?)

Visible LightVisible Light – the only radiation you can see. – the only radiation you can see.

Continued…Continued…

Ultraviolet RadiationUltraviolet Radiation – strong radiation that can – strong radiation that can make you tan and get cancer. (Can you make you tan and get cancer. (Can you

see see them?)them?)

X-RaysX-Rays – dangerous radiation that can go – dangerous radiation that can go through to your bones. (can you see them?)through to your bones. (can you see them?)

Gamma raysGamma rays - the most powerful radiation. - the most powerful radiation. Very dangerous. Found in a nuclear Very dangerous. Found in a nuclear explosion. explosion.

Visible LightVisible Light Humans can only see Humans can only see

visible light.visible light.

Visible light is made up of Visible light is made up of all of the colors of the all of the colors of the rainbow:rainbow:

RedRed OrangeOrange YellowYellow GreenGreen BlueBlue IndigoIndigo VioletViolet

How visible light travels…How visible light travels…

Visible Light travels in waves…Visible Light travels in waves… BUT, the waves are so small that from far BUT, the waves are so small that from far

away it looks like a straight line.away it looks like a straight line. SO…from now on we will ONLY say that SO…from now on we will ONLY say that

light travels in a straight line.light travels in a straight line.

Light Does 4 Things When it Hits an Object:Light Does 4 Things When it Hits an Object:

ReflectionReflection

Transmittance Transmittance

AbsorptionAbsorption

RefractionRefraction

The 2 Angles in a ReflectionThe 2 Angles in a Reflection

How are the 2 angles related?How are the 2 angles related?

The angle of incidence and the angle of The angle of incidence and the angle of reflection are ALWAYS the same!!!reflection are ALWAYS the same!!!

Remember:Remember: The colors of the rainbow are:The colors of the rainbow are:

RRed, ed, OOrange, range, YYellow, ellow, GGreen, reen, BBlue, lue, IIndigo, and ndigo, and VViolet.iolet.• All the colors of the rainbow are ROY G. BIV.All the colors of the rainbow are ROY G. BIV.

PrismsPrisms

What did you notice What did you notice when the light hit the when the light hit the prisms???prisms???

The reason a rainbow The reason a rainbow appeared is because appeared is because the light was...the light was...

REFRACTED.REFRACTED.

Visible LightVisible Light

Each color of the Each color of the rainbow has a rainbow has a different size wave. different size wave.

Some colors are Some colors are stronger than othersstronger than others Red is weakestRed is weakest Violet is strongest.Violet is strongest.

Visible LightVisible Light

What does this say about white light (visible What does this say about white light (visible light)?light)? VISIBLE LIGHT (white light) IS MADE UP OF ALL VISIBLE LIGHT (white light) IS MADE UP OF ALL

COLORS OF THE RAINBOW!!!!!COLORS OF THE RAINBOW!!!!!

ColorsColors

White light is hitting the White light is hitting the apple. apple.

Every color of the rainbow Every color of the rainbow is being absorbed by the is being absorbed by the apple EXCEPT the color apple EXCEPT the color red. red.

The red light that is The red light that is reflected bounces to your reflected bounces to your eyes and you see red.eyes and you see red.

LensesLenses A lens is a clear object that refracts light so that A lens is a clear object that refracts light so that

you can see a bigger version of an object.you can see a bigger version of an object.

LIGHT TESTLIGHT TEST The following vocabulary words will appear on The following vocabulary words will appear on

your test:your test: RadiationRadiation Electromagnetic spectrumElectromagnetic spectrum Radio waves, Microwaves, Infrared Radiation, Visible Radio waves, Microwaves, Infrared Radiation, Visible

Light, Ultraviolet Radiation, X-Rays, Gamma RaysLight, Ultraviolet Radiation, X-Rays, Gamma Rays Reflection, Refraction, Absorption, TransmittanceReflection, Refraction, Absorption, Transmittance Angle of Incidence & Angle of ReflectionAngle of Incidence & Angle of Reflection White LightWhite Light ROY G. BIVROY G. BIV PrismPrism LensLens

LIGHT TESTLIGHT TEST In order to pass, you must know the following:In order to pass, you must know the following:

What is the electromagnetic spectrum and how much What is the electromagnetic spectrum and how much is visible to humans?is visible to humans?

How does visible light appear to travel?How does visible light appear to travel? What 4 things can happen when visible light hits an What 4 things can happen when visible light hits an

object?object? How are the angle of incidence and angle of reflection How are the angle of incidence and angle of reflection

related?related? How are humans able to see objects?How are humans able to see objects? Why are objects a certain color?Why are objects a certain color? Which kind of lens would you use to see different Which kind of lens would you use to see different

sized things?sized things?