Further to “Can physics tell us if time had a beginning?”, a look at physicist Ethan Siegel’s reflections on the subject, Rob Sheldon responds,
A nice tutorial on how important metaphysics is for doing cosmology.
According to Ethan Siegel, inflation has been “proven” by the WMAP/Planck satellites. If you talk to a “inflation expert”, there isn’t a single model that works. What a contrast! Just like Darwinism. For the masses, it’s a proven fact, for the experts its an unworkable model. You’d be far more accurate just ascertaining the metaphysics of the scientist, and then you’d know precisely which models he will call facts. So if you want to know where Ethan Siegel stands on inflation and multiverses, just ask if he believes in the Creation of the Universe, as has been commonly held for the past 2000 years. The rest of the tutorial is just powerpoint animations of the metaphysics.
Great animations though.
See also: The Science Fictions series at your fingertips (cosmology).