Read through this page and this page only before you begin, so that you know what you are reading for.
Respond to the questions (Q) on a sheet of paper as you explore the websites linked below. Corresponding textbook sections are noted.
Wikipedia on Light
Light
27.1 Early Concepts of Light
Is light a wave, or a particle? On this page, find a brief history of early evidence.
Q1:List the properties of light that support the particle idea, and list the properties that support the wave idea.
27.2 The Speed of Light
Here is a link to an animation of the Michelson-Morely experiment: Michelson-Morley 1 . It is a simple animation showing the movement of the mirrors. Play all the animations and look at the calculation.
Q2: What is the object that rotates? What was its role in the experiment? How many sides did it have? Why were the number of sides important?
Another animation is found at Michelson-Morley 2
Read the brief commentary. To work the demo, choose light speed and aether speed on the left of the animation. Then click PLAY on the right. Try several combinations.
Q3: What was the purpose of this experiment? How did the concept of "aether "
Q4: What is the value for the speed of light (c) to the nearest meter?
Q5: Why was the letter c reputedly used to represent the speed of light?
Q6: Why is the speed of light considered to be a definition and not an actual measurement?
An interactive graphic of our nearest stars - read the intrroduction/key, then click map. Be sure to use your mouse to click and drag to rotate the image.
27.3 Electromagnetic Waves
This is a link to a nice overview of electromagnetic radiation. You will find the graphics helpful.
In class, we looked at the concept of light as part of the electromagnetic spectrum that your eyes can detect. Here is an animation of an EM wave.
Q7: Write the equation relating speed of light to wavelength and frequency. Rearrange it to solve for wavelength given frequency and then rearrange to solve for frequency given the wavelength.
Q8: Given that 1Å (Angstrom) = 1 x 1010 m, calculate the wavelength of a light wave having a frequency of 6.2 x 1014 Hz. What color light will result from this wave?
27.4 Light and Transparent Materials
27.5 Opaque Materials
Transparency, Opacity, and Shadows
Q9: Define transparent, opaque, and shadow.
27.6 Shadows
Study the following eclipse links.
lunar eclipse animation- scroll down to animation links
Solar Eclipses - scroll down to animation links
Q10: Write a brief comparison of solar and lunar eclipses.How is the term "shadow: used with respect to eclipses? Is this use correct?
27.7 Polarization
What is polarization? Go through the pages, paying attention to the interactive graphics and playing with them.TWIST the lenses by clicking and dragging.
Q:11 Explain how you would arrange 2 polarized lenses to block all light.
Examine what happens to light as you change the refractive index, the view angle, or the wavelength on this applet:
Q 12: Describe what happens as youincrease and decrease each variable in this animated graphic.
27.8 Polarized Light and 3-D viewing
Q13: How are 3-d images formed, and what is the more optimal way of making them?
Color
28.1 The Color Spectrum
Read, and be sure to look at the spectra of different elements.
28.2 Color by Reflection
28.3 Color by Transmission
Read this tutorial and answer the questions at the end.
Q14 : Use a diagram to describe what happens to different colored wavelengths of light as they are A. reflected and B transitted. You need only do an example of one color for each A and B.
28.4 Sunlight
Q15: Do a web search and describe the make-up of sunlight.
28.5 Mixing Colored Light
28.7 Mixing Colored Pigments
Drag the colored beams of light to mix them.Change to pigment mode and mix pigments.
Q16 : Describe what you saw as you mixed A. colored light beams and B. colored pigments. How were they different?
More colors to blend and mix.
Try to match the colors.
28.6 Complementary Colors
28.8 Why the Sky is Blue
28.9 Why Sunsets are Red
28.10 Why Water is Greenish Blue
Q17: I looked up the other sites. It is now your turn to look up one of these topics to share in class tomorrow. If your assigned seat is in Row 1 (closest to the classroom door) look up Complementary colors. If you are in row 2 (next to row 1...) you are to look up Why the Sky is Blue. If you sit in Row 3 (next to the row by the windows) you are to look up Why sunsets are red. And if you sit in the row nearest the windows, you are to look up why water is greenish-blue. Write an explanation, complete with a diagram, to share in class.
28.11 The Atomic Color Code: Atomic Spectra
The Bohr Atom Spectra. You will need to read the directions before beginning the animation.
An interesting color site
Read these links:
Rainbows
Q18: How many orders of rainbows have been observed?
A rainbow to play with:
Q19: Explain how the phenomena observed in this photo is caused:
Click here for a larger image of this Hood Canal Rainbow
