Fascination with the riddle of time is as old as human thought. The earliest written records betray confusion and anxiety over the nature of time. Much of Greek philosophy was concerned with making sense of the concepts of eternity versus transience. The subject of time is central to all the world’s religions and has for centuries been the source of much doctrinal conflict.
Although time entered science as a measurable quantity with the work of Galileo and Newton, it is only in the present century that it has developed into a subject in its own right. Albert Einstein, more than anyone else, is responsible for this advance. The story of time in the twentieth century is overwhelmingly the story of Einstein’s time. Although I have sketched biographical details where appropriate, this book is not a biography of Einstein, because several such have appeared since his centenary in 1979.
Although Einstein’s theory of relativity is nearly a century old, its bizarre predictions are still not widely known. Invariably people learn of them with delight, fear, and perplexity. The broad conclusion, however, is that we are far from having a good grasp of the concept of time. Einstein’s work triggered a revolution in our understanding of the subject, but the consequences have yet to be fully worked out. Much of the theory of relativity remains an uncharted territory, and crucial topics, like the possibility of time travel, have only very recently received attention. There are also major problems which hint at deep-seated limitations of the theory; discrepancies concerning the age of the universe and obstacles to unifying Einstein’s time with quantum physics are two of the more persistent difficulties.
Perhaps more worryingly, Einstein’s time is seriously at odds with time as we human beings experience it. All this leads to the belief that we must embrace Einstein’s ideas but move on. The orthodox account of time frequently leaves us stranded, surrounded by a welter of puzzles and paradoxes. Maybe Einstein’s time is inadequate to explain fully the physical universe and our perception of it.
The scientific study of time has proved to be disturbing, disorienting and startling. It is also befuddling.