When I agreed to lecture to-night I stipulated that I might be allowed to interpret the subject announced so as to let my treatment relate less to the subject in general than to some particular aspects which happen to have been interesting me lately. Professor Whitehead, Sir Arthur Eddington, and Sir James Jeans have given to the world brilliant accounts of the present position of physics in relation to mathematics and philosophy. What I have to say bears to their writings, (...) the humble relation of an example to a piece of book-work, or of an application of a theorem to the theorem itself. (shrink)

I think that to Lord Kelvin is attributed the saying that the scientific attitude to a thing, if you can't do anything else with it, is to measure it. This is the attitude I propose to adopt towards Time . The situation is to some extent analogous to the situation with regard to electricity . Science is unable to say what electricity is, and so it almost denies the word any entrance into a treatise on the subject. It replaces it (...) by the word charge , which is something that can be measured. It is important to avoid hypostatizing time into a thing-in-itself. Instead of trying to say what time is we try to find a way of measuring it. (shrink)

Recent results in kinematics, obtained by myself and those working with me, have convinced me that the philosophical status of physics, as it has come down to us from Renaissance days, requires reconsideration. The reason can be stated in a couple of sentences: it has been found possible to establish certain laws of physics—laws of motion, the law of gravitation, the laws known under the name of the Lorentz transformation, and some others—purely deductively, without specific assumptions, and without empirical appeals (...) save only to the empirical awareness of something we call “the passage of time.” Yet physicists have claimed ad nauseam that the ultimate sanction for “laws of nature” is observation and experiment, that this is what distinguishes physics from other branches of exact inquiry. The contrast in these two conceptions of natural law needs no emphasis. It is the purpose of this article to attempt to clarify this confused situation. (shrink)