1911: The Paradox About Time

Abstract

Einstein’s deduction of the time dilation was possibility the most difficult idea for both scientists and the lay public to fathom. It led to what was perceived by some as a paradox – usually called the clock paradox or the twin paradox. Before this paradox was invented, Einstein presented his interpretation of the time dilation in a lecture in Zürich in January 1911 (note the title): “The Theory of Relativity.” He spoke of the time dilation as both “peculiar” (a term he used before), and as “funny,” for if a clock moved near the speed of light and returned to its place of origin, the hands of the clock hardly moved compared to an identical clock at rest at the place of origin. More importantly, he made it clear that his interpretation inferred not only that the clock slowed down proportional to its speed but time itself proceeded more slowly, so that “a living organism” aged at a slower rate than one at rest. Here he explicitly affirmed what was implied in 1905 – that time itself, not just the ticking of clocks, changed. Einstein’s published lecture, however, was not widely read.