Michael J. Disney
Michael J. Disney is emeritus professor in the School of Physics and Astronomy at Cardiff University. He has done research on stars, pulsars and quasars, but his main interest has always lain in galaxies and in designing novel instruments to observe them at many wavelengths. He has worked on the development of Hubble Space Telescope instruments since 1976. Address: School of Physics and Astronomy, Cardiff University, 5 The Parade, Cardiff, Wales, CF24 3AA, U.K. Internet: mjd@astro.cf.ac.uk
It is true that the modern study of cosmology has taken a turn for the better, if only because astronomers can now build relevant instruments rather than waiting for serendipitous evidence to turn up. On the other hand, to explain some surprising observations, theoreticians have had to create heroic and yet insubstantial notions such as "dark matter" and "dark energy," which supposedly overwhelm, by a hundred to one, the stuff of the universe we can directly detect. Outsiders are bound to ask whether they should be more impressed by the new observations or more dismayed by the theoretical jinnis that have been conjured up to account for them.
My limited aim here is to discuss this dilemma by looking at the development of cosmology over the past century and to compare the growing number of independent relevant observations with the number of (also growing) separate hypotheses or "free parameters" that have had to be introduced to explain them. Without having to understand the complex astrophysics, one can still ask, at an epistemological level, whether the number of relevant independent measurements has overtaken and comfortably surpassed the number of free parameters needed to fit them—as one would expect of a maturing science. This approach should be appealing to nonspecialists, who otherwise would have little option but to believe experts who may be far too committed to supply objective advice. What one finds, in my view, is that modern cosmology has at best very flimsy observational support.
[SIZE=-1]A witch! A witch! A witch! WITCH[/SIZE]Where Do We Stand Today?
Big Bang cosmology is not a single theory; rather, it is five separate theories constructed on top of one another. The ground floor is a theory, historically but not fundamentally rooted in general relativity, to explain the redshifts—this is Expansion, which happily also accounts for the cosmic background radiation. The second floor is Inflation—needed to solve the horizon and "flatness" problems of the Big Bang. The third floor is the Dark Matter hypothesis required to explain the existence of contemporary visible structures, such as galaxies and clusters, which otherwise would never condense within the expanding fireball. The fourth floor is some kind of description for the "seeds" from which such structure is to grow. And the fifth and topmost floor is the mysterious Dark Energy, needed to allow for the recent acceleration of cosmic expansion indicated by the supernova observations. Thus Dark Energy could crumble, leaving the rest of the building intact. But if the Expansion floor collapsed, the entire edifice above it would come crashing down. Expansion is a moderately well-supported hypothesis, consistent with the cosmic background radiation, with the helium abundance and with the ages inferred for the oldest stars and star clusters in our neighborhood. However, finding more direct evidence for Expansion must be of paramount importance.
In the 1930s, Richard Tolman proposed such a test, really good data for which are only now becoming available. Tolman calculated that the surface brightness (the apparent brightness per unit area) of receding galaxies should fall off in a particularly dramatic way with redshift—indeed, so dramatically that those of us building the first cameras for the Hubble Space Telescope in the 1980s were told by cosmologists not to worry about distant galaxies, because we simply wouldn't see them. Imagine our surprise therefore when every deep Hubble image turned out to have hundreds of apparently distant galaxies scattered all over it (as seen in the first image in this piece). Contemporary cosmologists mutter about "galaxy evolution," but the omens do not necessarily look good for the Tolman test of Expansion at high redshift.
In its original form, an expanding Einstein model had an attractive, economic elegance. Alas, it has since run into serious difficulties, which have been cured only by sticking on some ugly bandages: inflation to cover horizon and flatness problems; overwhelming amounts of dark matter to provide internal structure; and dark energy, whatever that might be, to explain the seemingly recent acceleration. A skeptic is entitled to feel that a negative significance, after so much time, effort and trimming, is nothing more than one would expect of a folktale constantly re-edited to fit inconvenient new observations.
The historian of science Daniel Boorstin once remarked: "The great obstacle to discovering the shape of the Earth, the continents and the oceans was not ignorance but the illusion of knowledge. Imagination drew in bold strokes, instantly serving hopes and fears, while knowledge advanced by slow increments and contradictory witnesses." Acceptance of the current myth, if myth it is, could likewise hold up progress in cosmology for generations to come.
Burn the witch! Buuuuuuuuuuuurn the witch!
Six days of creation is NOT more crazy that 15 billion years and BB.
The funny thing is, I raised most of Disney's objections, with different words, and as a creationists. It was all completely dismissed here as having no basis in science. That's what they do instead of burning people alive like they used to.