Everyone educated past freshman biology can answer chlorophyll.
But science played a dirty trick— a bit of sophistry. Because whether by experimentation or experience it is proven that chlorophyll and greenness are inextricable, it is impossible by the same experience or experimentation to claim to first graders, post-grads, or great-grandpas that chlorophyll is “why grass is green.”
As if chlorophyll makes grass green. Anything making something else implies a will. I am not arguing for a minute that there is not a will behind grass being green, I am merely stating for eternity that it isn't chlorophyll.
It is just as scientific and certainly more historically accurate—in the sense of one thing causing another—to say green grass made chlorophyll. Some might say it is splitting chromosomes to add that DNA makes chlorophyll. But it is neither DNA nor chlorophyll that is the problem or the answer, it is science's claim of who or what makes what that is the problem. The fact that grass is green, not chlorophyll or martians or envy, asks a question-- a deep question about creation and will rather than the shallow one modern science magically solves with a thin paste of complicated terms. Why is grass short rather than tall as a giant beanstalk?
I am simply trying to point out it, at the risk of growing the metaphor too long, it is more correct to say lawnmowers make grass short than grass DNA does. Because the location of will is properly positioned.
I might as well say that eyes make men see. No they don’t. Eyes and seeing are the same thing. Eyes didn’t come before seeing. They arrived at the exact same time. Man wasn’t made to see by his eyes, but he does see. Why?