What would a scientist use a prism for ?

Question

What would a scientist use a prism for ?

Answer 1

To split white light/natural light into the visible-light spectrum.

Answer 2

He or she can use it for dispersing white light into its components.

Answer 3

to look through it to see the spectrum of light

Answer 4

You could drop one from the top of a building with known height, and time how long it takes to hit the ground.  That might give you an estimate of the local gravity.

You can also separate the colors of light out, which can be handy for discovering what elements were present in the material that made the light, as well as what elements absorbed light on it's way to you.