Contemporary Cosmological Theory (from Evolutionary Theory Conference Summary), Esalen Center for Theory & Research

Evolutionary Theory
An Esalen Invitational Conference
November 14-19, 1999

Contemporary Cosmological Theory
Tony Rothman

Tony Rothman’s presentation was a cogent overview of current cosmological theory, including the big bang, the inflationary hypothesis, and the anthropic principle. Starting with the origin of it all, the so-called big bang, Rothman pointed out that this term is actually quite misleading because there never was a gigantic explosion, as the term might lead one to believe. Rather, in the beginning, time and space as we know it came into existence as the universe started to expand. Since all of time and space were present at the origin of the universe, we can say that the big bang was/is everywhere still today. That is, even at the big bang, the universe was everything and (if the universe is of the ever-expanding type) was infinite in size even then. Ever since Edwin Hubble observed the recession of the galaxies in 1929, we have empirical evidence that we live in an expanding universe. Furthermore, no matter what direction we look in through our telescopes, the expansion is equal in all directions. Next Rothman pointed to the discovery in 1965 of the background radiation that is a left-over of the big bang—or, to be more accurate, is a left over of the decoupling of photons when matter first formed. This occurred not at the big bang, but, according to most estimates, 350,000 years afterwards. In 1989 we sent the COBE satellite into space, which confirmed our observations of the background radiation.

One of Rothman’s major points was that there are multiple theories and models to explain the data that scientists have observed and collected. We are far from a consensus in our understanding of the universe. For example, how do we account for the complexity of the universe, the clumping of matter into beautiful galaxies, if the big bang was smooth and uniform at the start? Rothman pointed to one explanation offered by the physicist Alan Guth who proposed the inflationary hypothesis. This theory maintains that the universe expanded at a super-fast rate just for a brief moment right after the big bang. Its strength is its ability to account for the fact that our calculations show that there must be more matter in the universe than we can observe.

Rothman also noted the fact that some recent scientific data indicates that the universe’s expansion may actually be accelerating, which would seem to counteract the power of gravity, which is pulling all of the matter of the universe back together. However, these observations need to be confirmed and there are other ways of interpreting the data. Rothman discussed the commonly used terms: flat, open, and closed. A flat universe is one in which the density of matter is at a critical value, called an omega=1 universe. An open universe is one in which the expansion will continue forever, and a closed universe has a spherical shape. Scientists still debate which is the most accurate model for our observations.

An interesting point in Rothman’s presentation came when members of the audience discussed the numerous “close calls” of the universe. At the very beginning of the universe, matter and anti-matter collided violently and destroyed each other, but, miraculously a small fraction of matter was left over after this dance of mutual annihilation, and this is what constitutes the matter of our universe. Another close call that Fred Hoyle pointed out was the synthesis of carbon in red giant stars. If it had not happened exactly as it did, we would not be here today. This, of course, leads to the controversial anthropic principle, which asserts that were the universe any different, life would not have arisen and we would not be here to observe it. The physicist, John Wheeler, went further and proposed “the participatory anthropic principle” which holds that it is our participation, our observation, of the universe that brings the universe into existence at the quantum level. This version, however, is not accepted by many physicists.

Rothman cautioned against taking popular pronouncements on cosmology too seriously, particularly in light of the new flood of observations. Because the universe is everything and much lies beyond any distance that we will conceivably ever see, we will almost certainly never have definitive answers to questions like “what caused the big bang?” In conclusion, Rothman offered his agreement with J.B.S. Haldane, who said that not only is the universe queerer than we suppose, but it is queerer than we can suppose.