Polarization, Diffraction, Huygens' principle, interference

1. Today: More wave properties of light Polarization, Diffraction, Interference Exam 2 is Thursday, Bring a Pencil!

2. HW Exeperiment 2/13/04 Calendar note: Looking out airplane window. Very bright cloud floor. See bright (white) point-like flashes. 100's of ms in duration. Seem to appear, then travel in short paths (like 1% of field of vision), sometimes squiggly lines, sometimes curly orbits. Probably 1000's in field. Ideas: 1. Recreate indoors? 2. W/ sunglasses or other optics 3. W/ eyes closed and bright? 10/27/06 Colleague visits ABQ: He calls them “wormy things” and sees them on airplane. He speculates they are due to low pressure, something about your eyeball pressure being too high? This convinced me to do some poking around We were screwed by the weather! I don’t think anyone saw what I’m going to talk about Kyle Dallas: But when it cleared up a little bit I was looking at a angle in which the sun was behind the clouds…noticed that the sky was a darker blue above the clouds where the sun light was easier to see cutting into the blue sky. Lisa Gillim: The blue from the sky reflects off the clouds making it look like they have a blue outline. (Silver lining?) Kayla Deresin: …the part of the sky that i did get to see was a violet blue and if i looked really hard I could see a little bit of green and I am not sure why that is!

4. Blue Field Entoptic Phenomenon http://webvision.med.utah.edu/sretina.html

5. Quiz 6

10. EM Waves can be “linearly polarized” Similarly, a transverse wave on a rubber tube has a polarization hyperphysics.phy-astr.gsu.edu

11. The “rope through a fence” analogy is misleading! This is how EM radiation interacts with matter vertical polarization is let through horizontal polarization is absorbed Let’s confirm this again with the microwave demo and the metal combs

16. “ Diagonally” polarized light can be thought of as a combination of horizontal and vertical. If a polarizer is at an angle relative to light polarization, some light will go through… But polarization of light going through will be rotated! First this applet: http://www.colorado.edu/physics/2000/polarization/blocking_light.html Confirm with microwaves again. Laser experiment