Light & MatterLight & Matter

We see the objects around We see the objects around us because light waves are us because light waves are reflectedreflected off objects to our off objects to our eyes.eyes.

Light & MatterLight & Matter

OpaqueOpaque objects only objects only reflect light, reflect light, they do not they do not allow light to allow light to pass through.pass through.

[http://www.harcourtschool.com/glossary/science/images/gr6/trans_opaque6.jpg]

Light & MatterLight & Matter

TranslucentTranslucent objects allow objects allow light to pass light to pass through, but through, but you cannot you cannot see clearly see clearly through them.through them.

[http://www.harcourtschool.com/glossary/science/images/gr6/trans_opaque6.jpg]

[http://images.google.com/images?q=tbn:WAydjyn5nFEJ:gnr8.typepad.com/gnr8_news/images/concrete1.jpg]

Light & MatterLight & Matter

TransparentTransparent objects allow objects allow you to see you to see light clearly light clearly through them.through them.

Examples on Examples on pgs. 420-421pgs. 420-421

[http://www.harcourtschool.com/glossary/science/images/gr6/trans_opaque6.jpg]

Reflection of LightReflection of Light Regular ReflectionRegular Reflection

occurs when light occurs when light waves bounce off a waves bounce off a smooth surface.smooth surface.

Usually you see a Usually you see a reflection, like with reflection, like with mirrors or windows.mirrors or windows.

Law of ReflectionLaw of Reflection[http://cougar.slvhs.slv.k12.ca.us/~pboomer/physicstextbook/fig13-3.jpg]

Click Here for a Regular Reflection Example

Reflection of LightReflection of Light

Diffuse ReflectionDiffuse Reflection occurs when light occurs when light waves bounce off waves bounce off rough surfaces.rough surfaces.

This occurs with This occurs with most objects we most objects we see.see.

[http://upload.wikimedia.org/wikipedia/en/thumb/7/79/Diffuse_reflection.PNG/180px-Diffuse_reflection.PNG]

Refraction of LightRefraction of Light

When a wave When a wave changes changes mediums it mediums it slows down slows down and bends.and bends.

Refraction of LightRefraction of Light

Index of refractionIndex of refraction - - How much a material How much a material changes the path of changes the path of a light wave.a light wave.

The larger the index, The larger the index, the more it bends.the more it bends.

Click here for a refraction animation

[http://micro.magnet.fsu.edu/optics/lightandcolor/images/refractionfigure1.jpg]

Click Here for the Disappearing Beaker Demo

Refraction of LightRefraction of Light PrismsPrisms bend bend

“white light” “white light” enough to split it enough to split it into the colors of into the colors of the rainbow.the rainbow.

Refraction of LightRefraction of Light

Red has the Red has the largest largest wavelength and wavelength and bends the least.bends the least.

Violet is the Violet is the opposite.opposite.

[http://selfpursuit.com/files/2007/08/wp-contentuploadsspectrum.jpg]

MiragesMirages occur occur when light is when light is refracted through refracted through different densities different densities of air.of air.

Usually air is Usually air is warmer right warmer right above pavement.above pavement.

Refraction of LightRefraction of Light

[http://ophtasurf.free.fr/mirages/mirage2.jpg]