The document discusses the Big Bang theory and the origin and expansion of the universe. It describes how Hubble's law shows that galaxies are moving away from us and the farther away they are the faster they recede. This implies that at one time all galaxies were closer together, providing evidence that the universe began in an event known as the Big Bang about 13 billion years ago. More recent observations of distant supernovae also indicate that the expansion of the universe is accelerating over time due to an unknown form of dark energy.

1. The Big Bang Where do we come from, where are we going?

18. Baby Boomer Universe Farther away we look, further back in time we see! 60s 50s 40s 90s 80s 70s

19. What We See