ah yes, the deepest questions in physics:
- what exactly is stuff
- what exactly is time
- how do you reconcile general relativity and quantum field theory into a theory of everything
- why is there so little anti-stuff
- why is stuff three-dimensional
- why is time one-dimensional
- how do you accurately model fluid flow in turbulent conditions
- how the fuck do ice skates work
I love that "unanswered questions in physics" is a category that contains both questions that are really easy to state to a layperson (including ones that seem very simple and easy and are very much not) and questions that require a background in physics to even know what they're asking
"unanswered questions in mathematics" is like this too
and "unanswered questions in biology" has a few easy-for-laypeople-to-understand questions like "why do most animals need sleep" but is mostly full of questions you need a background in biology to understand
