What is the color of a wave that has a frequency of 600.0 terahertz?

1 Answer
Dec 11, 2015

Green

Explanation:

A terahertz is 10^12 hertz, it is a unit of frequency.

600 THz = 600 times 10^12 Hz

Let's convert this to nanometers and the look this up in a table to see what color our eyes would see. A nanometer is 10^-9 m.

Converting to nanometers is not strictly necessary, but as an optical astronomer, I have a better intuition for the color of things given in the wavelength of their light.

v = f lambda
lambda = v /f

Where lambda is the wavelength, and v is the velocity of our wave. Since we are dealing with light, we know the velocity is c = 3 times 10^8 m/s.

lambda = {3 times 10^8 m/s} / {600 times 10^12 Hz}

lambda = 5 times 10^-7 m
lambda = 500 nm

Using the table here
we see that this is green light.