Inspiration

What was Maxwell's demon again?

When I was a junior high school student, I actively bought books from a series called "Blue Backs" and read five or six of them. The "uncertainty principle" also just came to mind, but what kind of principle was it?

I feel like this concept of "waves and particles" could be replaced or substituted with "time and space."

Einstein said—or I feel like he said—that intense inspiration is the most important thing in physics.

It means reaching a truth that cannot be arrived at by inspiration alone, and later proving it in the world of mathematics.

In one of the books from that series I read long ago, it mentioned that the only impossible thing is to change causality. Could I please hear your thoughts on this?