# Wavelength speed differences

1. Dec 16, 2012

### Fonzi03

Would light at 10nm be traveling at a slower speed due to having to go a shorter distance than light at 1mm? The IR light is traveling a straighter line to its destination than the UV so for both of them to arrive at the same time the UV must be going faster in order to make up time and be at the same destination at the same time as the IR right?

2. Dec 16, 2012

### bcrowell

Staff Emeritus
Let's back up and think about water waves. If you throw a stick in the ocean, the waves don't wash it up on the shore. (That only happens if there's a wind.) The wave pattern moves smoothly in one direction, toward the beach. The water oscillates. The two motions are completely different.

A transverse wave isn't traveling along a sinudoidal path, so it's not right to imagine that there is extra distance involved.

3. Dec 17, 2012

### nitsuj

Maybe better to consider the peaks & troughs of a wavelength as "phases", but not a traveled distance.