ABSTRACT
Everybody who has ever heard of relativity knows the phrase ‘space-time’, and knows that the correct thing is to use this phrase when formerly we should have said ‘space and time’. But very few people who are not mathematicians have any clear idea of what is meant by this change of phraseology. Before dealing further with the special theory of relativity, I want to try to convey to the reader what is involved in the new phrase ‘spacetime’, because that is, from a philosophical and imaginative point of view, perhaps the most important of all the novelties that Einstein introduced.
