ELI5: If the Big Bang was 13.8 billion light years ago, and nothing can travel faster than the speed of light, why does the universe have an estimated radius of 46 billion light years, and not 13.8 billion?
ELI5: If the Big Bang was 13.8 billion light years ago, and nothing can travel faster than the speed of light, why does the universe have an estimated radius of 46 billion light years, and not 13.8 billion?