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

The great spirals, with their enormous radial velocities and insensible proper motions, apparently lie outside our Solar system.

Science is the one human activity that is truly progressive. The body of positive knowledge is transmitted from generation to generation.

I knew that even if I were second or third rate, it was astronomy that mattered.

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

Observations always involve theory.

Wisdom cannot be directly transmitted, and does not readily accumulate through the ages.