Why?

About the below, about all the time spent understanding QM, some people ask, โ€œWhy bother? What does that gain you?โ€

Well, ignoring even the simple joy of understanding something for its own sake, I know why the sun shines. Not just some vague guess โ€“ I know exactly why. I know why photons are emitted, and under what conditions, and how a star keeps from collapsing under its own mass.

I know why my hand doesnโ€™t pass through the desk when I โ€œtouchโ€ it, even though itโ€™s mostly just empty space.

I understand why an element is an element, and why there are elements in the first place.

Knowing QM enough to reason in its counterintuitive way wonโ€™t help you make more money at work, or to repair your car, but when you look out at the universe or even at your own hand, youโ€™ll understand more about the world than most people who have ever lived.

If that isnโ€™t cool or worth doing, I donโ€™t know what is. I know how the sun shines. How many people in recorded history can say that?