human
What are the most popular questions that people have about astrophysics?
assistant
1. How did the universe begin?
2. Why is there a Big Bang singularity?
3. Is there life beyond Earth?
4. Are black holes really as small as they seem?
5. How do galaxies form and evolve?
6. How does gravity work?
7. How did stars and planets form?
8. How do stars and galaxies move?
9. How did the universe expand?
10. How do we know what we know about astronomy?