Distance is a scalar quantity that refers to "how much ground an object has covered" during its motion. Displacement is a vector quantity that refers to "how far out of place an object is"; it is the object's overall change in position.
You could probably expect normal plant growth, as a white light is similar to the sun in the respect that it contains all colors of the spectrum.
Here is the answer that completes the statement above. We can study how galaxies evolve because THE FARTHER AWAY WE LOOK, THE FURTHER BACK IN TIME WE SEE. This means that the more we discover more about what's happening in the universe, the more we become curious to know how and when it began. Hope this helps.