I'd recommend the book 'A Brief History of Time' by Stephen Hawking, or for the math side, 'The Joy of x.' Your library has them. They're written for curious regular people. You don't need a degree to understand the big ideas.

Scientists love this kind of question because it's how real discoveries start. 'That's funny...' is supposedly how a lot of breakthroughs begin. Keep that curiosity — it's worth more than memorizing facts for a test.

There's a great explanation of this on the HowStuffWorks website, and the NASA site has good material too if it's space-related. Both are written for normal people, not scientists, so you won't get lost in jargon.

This is actually a much deeper question than it appears on the surface. The simple answer most textbooks give is technically correct but misses a lot of nuance. Let me try to explain it in a way that captures the full picture.