Edwin Powell Hubble

The history of astronomy is a history of receding horizons.

Observation always involves theory.

The great spirals... apparently lie outside our stellar system.

Equipped with his five senses, man explores the universe around him and calls the adventure Science.

We find them smaller and fainter, in constantly increasing numbers, and we know that we are reaching into space, farther and farther, until, with the faintest nebulae that can be detected with the greatest telescopes, we arrive at the frontier of the known universe.