Equipped with our five senses - along with telescopes and microscopes and mass spectrometers and seismographs and magnetometers and particle accelerators and detectors sensitive to the entire electromagnetic spectrum - we explore the universe around us and call the adventure science.

Not until the empirical resources are exhausted, need we pass on to the dreamy realms of speculation.

There we measure shadows, and we search among ghostly errors of measurement for landmarks that are scarcely more substantial.

A scientist naturally and inevitably ... mulls over the data and guesses at a solution. He proceeds to testing of the guess by new data-predicting the consequences of the guess and then dispassionately inquiring whether or not the predictions are verified.

The history of astronomy is a history of receding horizons.

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

All nature is a vast symbolism: Every material fact has sheathed within it a spiritual truth.