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

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

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

The outstanding feature, however, is the possibility that the velocity-distance relation may represent the de Sitter effect, and hence that numerical data may be introduced into discussions of the general curvature of space.

Observation always involves theory.

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.

With increasing distance, our knowledge fades, and fades rapidly. Eventually, we reach the dim boundary-the utmost limits of our telescopes. There, we measure shadows, and we search among ghostly errors of measurement for landmarks that are scarcely more substantial. The search will continue. Not until the empirical resources are exhausted, need we pass on to the dreamy realms of speculation.