where do we come from? how did the universe begin?why is the universe the way it is? how will it end?

　　all my life, i have been fascinated by the big questions that face us, and have tried to find scientific answers to them.if, like me, you have looked at the stars, and tried to make sense of what you see, you too have started to wonder what makes the universe exist. the questions are clear, and deceptively simple. but the answers have always seemed well beyond our reach. until now.

　　the ideas which had grown over two thousand years of observation have had to be radically revised. in less than a hundred years, we have found a new way to think of ourselves. from sitting at the center of the universe, we now find ourselves orbiting an average-sized sun, which is just one of millions of stars in our own milky way galaxy. and our galaxy itself is just one of billions of galaxies, in a universe that is infinite and expanding. but this is far from the end of a long history of inquiry.

　　huge questions remain to be answered, before we can hope to have a complete picture of the universe we live in.

　　i want you to share my excitement at the discoveries,past and present, which have revolutionized the way we think. from the big bang to black holes, from dark matter to a possible big crunch, our image of the universe today is full of strange sounding ideas, and remarkable truths. the story of how we arrived at this picture is the story of learning to understand what we see.