Is the universe ultimately made of time or of timeless numbers? In a review of Unger and Smolin’s The Singular Universe and the Reality of Time, Bryan Appleyard discusses the “superstitions and allegories” of science, especially physics. “If, as Unger and Smolin insist, time is real and not simply an aspect of space or of our perceptions, then the laws of physics begin to look even less solid. If everything is subject to time and, therefore, change, then these laws can evolve. They suggest the idea that these laws are eternally fixed is a supersition caused by mathematics – all the insights of maths are timeless and maths is only a human creation. In fact, two of the greatest physicists of all time – Richard Feynman and Paul Dirac – both accepted the possibility that the laws of physics evolve through time. Yet eternal, immutable physical laws, somehow detached from our physical universe, remain one of the primary superstitions of our age.”
How can philosophers work with physicists to study the origin and development of the universe? Sean Carroll poses questions for the philosophy of cosmology. For example, are time and space fundamental features of the universe, or do they emerge from more basic features? Philosophers have considered time, space, and Carroll’s other questions throughout … well, over considerable time and space.
Tim Crane explains what metaphysics is about. “It’s abstract and not everyone’s cup of tea but, in many ways, inescapable. Cambridge University philosopher Tim Crane introduces the best books on metaphysics.”
Time travelers: please don’t kill Hitler. One of the most popular mind experiments for exmining theories of knowledge and theories of reality is time travel. And for time travelers, one of the most common scenarios (perhaps the most common) is killing Hitler. But … “in almost any science-fiction scenario involving time-travel, the default action is to kill Hitler. As terrible a human being as he was, there are many reasons why this probably isn’t a good idea.”