Some big questions
- Was the universe once of zero size?
- Probably not. But it was infinitely dense. It is wrong to think about ‘outside’
- What happened before this?
- Hard to be sure - maybe inflation (later). Something is needed to start the expansion
- What is the future of the expansion?
- That depends on what the universe contains. Best current idea is that it will expand indefinitely
- Why are there galaxies?
- We need to see some more evidence....