Tag Archives: physics

The Sound of Light

I was recently a guest in a classroom (not at APU) and listened to a fantastic composer and beloved professor tell a room full of eager students that the reason florescent lights buzz when they start to go bad is because some of the light is slowing down, and the frequency of the light is getting so slow that it becomes a sound wave instead of a light wave, which is why the buzz is at 60 Hz.

Nobody in the room contradicted him. Nobody. After about 30-second of dumb disbelief, I protested, and the whole class turned on me as if I were an idiot, daring to argue with this obviously brilliant man.

This brought to mind 3 things:

1. An expert in one area is not an expert in all areas. If you are a teacher, be sure you communicate to your students when you are speaking from your area of expertise, and when you are speaking out of your nether regions. If you are a student, become critically aware  of the difference. 
2. Intellectual authority comes from being right, not from being in a position of authority. Don’t be afraid to challenge professors when they are wrong.
3. In a room full of 20 people, I can’t believe nobody knew enough about light, or sound, or electricity to contradict an obviously absurd assertion. I’m worried that we’ve come to just accept general ignorance about how the world works.

So here’s today’s extra credit question. Help me restore my faith in the world. Without heading to wikipedia or google, with just your general knowledge of physics, what would you have said to the man to demonstrate his error?