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

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

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

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

Observations always involve theory.

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

The history of astronomy is a history of receding horizons.