A theory can be proved by experiment; but no path leads from experiment to the birth of a theory.

In theory, there is no difference between theory and practice. But, in practice, there is.

Sometimes a scream is better than a thesis.

A theory has only the alternative of being right or wrong. A model has a third possibility: it may be right, but irrelevant.

A theory can be proved by experiment; but no path leads from experiment to the birth of a theory.

A theory has only the alternative of being right or wrong. A model has a third possibility: it may be right, but irrelevant.