‘To measure the distance to Neptune, we work in parsecs, which are a parallax of one arcsecond. Actually, let’s just look at some pictures’
Cosmology is amazing. It allows us to dare to imagine a time when the entire observable universe was compressed into a region of space smaller than an atom. Imagine. The Milky Way, home to 400 billion stars, along with billions of other universes, all compressed into a sub-atomic patch. It feels mind-blowing, doesn’t it? Except it isn’t, really. And what this book is going to do is allow you to answer some of the big cosmic questions while lying down in your back garden after having a few drinks. How old is everything? How big is it? Science can tell you. All you have to do is stare into my amazing eyes and let yourself come on a journey.
Before the Big Bang, the universe was relatively cold and empty – a bit like your brain, I’m guessing – and those particles that did exist were moving apart from each other at a staggering rate. Two particles only one centimetre apart would be separated by 10 billion metres only 4 x 10-36 seconds later. It would probably help if you understood just how small a number 4 x 10-36 really is. Just try to think of the smallest thing you can think of and then imagine it much, much smaller. This period before Big Bang is known as the epoch of inflation. Don’t let’s worry about what happened before the epoch of inflation.