Cosmic Evolution and Big Bang

Question 1

What are the key problems with the standard Big Bang model?

Answer 1

1. Flatness Problem – Why is the universe so close to critical density?
2. Horizon Problem – Why is the Cosmic Microwave Background (CMB) temperature so uniform?
3. Monopole Problem – Why don’t we see predicted magnetic monopoles?

Question 2

How does cosmic inflation solve these problems?

Answer 2

Inflation exponentially expands the universe in a tiny fraction of a second, making it appear flat, homogeneous, and solving the horizon and monopole problems.

Question 3

What is the cosmic microwave background (CMB)?

Answer 3

The CMB is the leftover radiation from the time when the universe cooled enough for electrons and protons to combine (recombination), about 380,000 years after the Big Bang.