If you’re curious about the particular coloring pattern on a puffin, say, you can just go and look at one (or look at a photo someone else took of one). If, however, you’re curious, not about a puffin, but about Anchiornis huxleyi, a small, flying dinosaur that lived between 160 and 155 million years ago (and you don’t happen to be a scientist in the movie, Jurassic Park) things are not so easy. Paleontologists who study dinosaurs that have been extinct for millions of years are at quite an evidential disadvantage. They have to base their theories on traces of dinosaurs, such as fossilized bones, footprints and feathers.
David Lewis argues that past events leave multifarious traces which radiate outward, like the ripples in a pond. David Albert argues that we know such traces are reliable records because the universe Continue reading “Traces of Dinosaurs”
Why do we experience the world as unfolding in time? And why does it unfold toward the future rather than the past? One hint is provided by entropy: eggs break (but never un-break), we grow older (but never younger), ice melts when we add it to a pot of boiling water (but the boiling water never gets hotter while the chunk of ice gets bigger). Yet entropy itself requires an explanation because both entropic and anti-entropic behavior are compatible with the fundamental laws of physics. One solution was first explained in detail by David Albert, a philosopher at Columbia University, in his book, Time and Chance (2001). According to Albert, it is the big bang, which provides a low-entropy boundary condition, that explains the direction of time (and all of its associated puzzles). Now, Sean Carroll, a theoretical physicist at the California Institute of Technology has taken up Albert’s idea in his new book, From Eternity to Here. In a recent interview in Scientific American, Carroll claims “just about everything about the arrow of time—what we would think of as “how time works,” the fact that the past is set in stone while the future can still be altered—is all because of entropy.” Carroll’s book is intended for a popular audience, and would be a worthwhile investment for any philosopher curious about physics-based approaches to the metaphysics of time.
By Barry Dainton , University of Liverpool
(Vol. 3, June 2008)
By Frank Arntzenius , Rutgers University
(Vol. 1, October 2006)