The Green Ray

This summer, I was traveling with SAS Airlines.  The airlines added a tail camera view to the passengers' menu, so with a click on the screen we could choose to see the airplane flying some 40,000 feet above the ground.  What a cool feature!  

When watching the sunrise, I witnessed a rare occurrence of a green ray of the Sun.  I have heard about that phenomenon, but have never seen it.  It was astonishing to see; as a human, as a human, I just remained overwhelmed by the beauty of nature; as a physicist, I admired the refraction of light from a new perspective.  Here is the picture:

I’m not sure what’s going on...

Student: Professor, I’m not sure what’s going on but the image distance continues to increase while the focal length is the same.

Instructor: I think I know what is going on.  You just learned something about spherical mirrors!

Green Laser Reflection and Refraction

 

Anytime you observe reflection and refraction, you get actually multiple reflections and refractions.  Any reflected or refracted ray becomes an incident ray and is once again reflected or refracted at the boundary.  The useful skill is then to recognize which ray is which one and select only the those needed for the experimet.

Measuring the speed of sound - lab notes

TUNING FORK

Kirchhoff's Loop Rule once again

#1 #2   

We measure the drop of voltage on resistors in one loop.

The sum of the first, second, and third measurement is...

0.784 V + 0.218 V + (-1.002 V) = 0.000 V

#3

(measured by Samantha and Frangel)