Any writer trying to describe the size of the universe faces a dilemma, because the numbers involved are so extreme that some don’t think it’s necessary to try. But is there any book about the universe that you don’t even try? 　　We need to start by understanding the numbers involved in the physics of space. For example, 1 million seconds is equivalent to 11 and a half days, 1 billion seconds is equivalent to 32 years, and 1 trillion seconds is equivalent to 32,000 years. Keep this comparison in mind as we struggle to think about what is to come. 　　We also need to understand a fact: the distance from…