Physics of Light

Kristen Halls5/7/09

What is Light?

Does not need medium to travel through

Consists of energy in the form of electric and magnetic fields

Known as electromagnetic radiation

Light Waves

Come in many different sizes(size of wave measured in wave lengths)

Come in many different frequencies(# of waves that pass a point in space during a time interval)

Measured in Hertz (Hz)

Visible Light (aka Color)

Ranges from 430 trillion Hz, seen as red, to 750 trillion Hz, seen as violet

Violet has the most energy while red has the least

White Light?

When you look at the visible light of the sun, it appears white. But white isn’t a color!

Why?

Because white light is made up of many color frequencies.Rainbows show us this!

Making Colors

What happens when you mix different colors of light?

Our Results

Primary Colors of Light:Red, Green and Blue

Why is the sky blue? When sunlight enters atmosphere, it collides with the oxygen and nitrogen atoms.

The colors with the shorter wavelengths are scattered more by this collision

Violet and blue are the shortest wavelengths but our eyes are more sensitive to blue light so we a blue sky

But then why are sunsets red?Sunsets are reddish because the sun is not directly overhead

Rays must cross through much more atmosphere

After having crossed so much air, most of the blue light is scattered out, as well as most of the green. This leaves the red, yellow and orange colors

Take a look over this comic when you are finished with your lab and think about what the correct answers are to Calvin’s (the little boy’s) questions.

Information Credits http://www.physlink.com/Education/AskExperts/ae228.cfmhttp://www.why-is-the-sky-blue.tv/why-is-the-sky-blue.htmhttp://science.howstuffworks.com/sky1.htm http://science.howstuffworks.com/light14.htm

Photo Credits

http://www.faqs.org/photo-dict/photofiles/list/699/1110prism.jpghttp://en.wikipedia.org/wiki/File:Cloud_in_the_sunlight.jpg http://cmb.physics.wisc.edu/tutorial/Hubble_Expansion/doppler.gif http://www.windows.ucar.edu/physical_science/magnetism/images/visible_spectrum_waves_big.jpg http://farm4.static.flickr.com/3171/3114871924_3abf540863.jpg http://www.partyandpaperwarehouse.com/media/cellowrap.jpg http://www.lakewoodconferences.com/direct/dbimage/50276506/27_LED_Flashlight.jpg http://www.sweethaven02.com/Photog01/fig1201.gif http://science.howstuffworks.com/sky.htm http://optics.kulgun.net/Blue-Sky/red-sunset-casey1.jpg http://everwhat.wikispaces.com/file/view/Sun_Set-Calvin_&_Hobbes.gif