The idea that time is only an illusion caused because we are constrained to live in four dimensions in what is by nature a higher dimensional universe is not really a new one. But this article in Discover magazine reports on someone who’s come to the same place via a different reasoning:
“‘One finds that time just disappears from the Wheeler-DeWitt equation,’ says Carlo Rovelli, a physicist at the University of the Mediterranean in Marseille, France. ‘It is an issue that many theorists have puzzled about. It may be that the best way to think about quantum reality is to give up the notion of time—that the fundamental description of the universe must be timeless.’
No one has yet succeeded in using the Wheeler-DeWitt equation to integrate quantum theory with general relativity. Nevertheless, a sizable minority of physicists, Rovelli included, believe that any successful merger of the two great masterpieces of 20th-century physics will inevitably describe a universe in which, ultimately, there is no time.
The possibility that time may not exist is known among physicists as the ‘problem of time.’ It may be the biggest, but it is far from the only temporal conundrum. Vying for second place is this strange fact: The laws of physics don’t explain why time always points to the future. All the laws—whether Newton’s, Einstein’s, or the quirky quantum rules—would work equally well if time ran backward. As far as we can tell, though, time is a one-way process; it never reverses, even though no laws restrict it.
‘It’s quite mysterious why we have such an obvious arrow of time,’ says Seth Lloyd, a quantum mechanical engineer at MIT. (When I ask him what time it is, he answers, ‘Beats me. Are we done?’) ‘The usual explanation of this is that in order to specify what happens to a system, you not only have to specify the physical laws, but you have to specify some initial or final condition.’”
Most people I’ve read have said that the arrow of time arises because of the Law of Entropy (from Thermodynamics) which is also the reason you can’t un-stir a cup of coffee. This article goes on to say that the fact that there was a big-bang (or a beginning to the Universe) is what fundamentally gives time its apparent directionality.
Read the rest here: Newsflash: Time May Not Exist | Physics & Math | DISCOVER Magazine