n1 * sin(theta1) = n2 * sin(theta2)
Another way to show the huge span of the electromagnetic spectrum is to compare it to ... a piano.
Joe (in Rochester) calls his friend Phillipe, who lives in Paris. As they talk, Joe notices something wierd -- there's always a short pause before Phillipe answers his questions.
"Are you playing some stupid video game?" he asks in an irritated tone of voice.
"Non," replies Phillipe after a pause of 0.48 seconds, "these delays are due simply to the speed of light."
Q: What does Phillipe mean? Q: Roughly how far above the surface of the Earth are communications satellites?
Let's watch some reflection in action
Q: What was the average distance between Earth and Moon during the given experiment? Q: By how much did this distance change during the roughly 4 minutes of the experiment? Q: Most of this change was due to the rotation of the Earth. Which way was the telescope pointing during the experiment? East South West
An applet showing individual wavefronts entering a new medium
There is a relatively simple relationship between the angle of the incident ray measured from the normal and the angle of the refracted ray measured from the normal.
Joe can move his laser pointer anywhere along a horizontal line 12 cm above the water's surface. He wants to strike the water at the point A, and have the beam hit the "X" at the bottom of the tank. How far along the green line from point A should Joe put his laser pointer?
Consider a prism of plastic in the form of an equilaterial triangle, with index of refraction n2 = 1.30. An incoming ray of blue light strikes the left face of the prism at angle theta1 = 30 degrees. Q: What is the angle theta2? Q: Angle theta3 = 60 - theta2. Can you figure out angle theta4?
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Let's watch some total internal reflection
Q: What angle should yield total internal reflection for a laser beam passing FROM water INTO air?