In the Beginning (Introduction)

by David Turell , Sunday, November 01, 2015, 20:54 (3309 days ago)

An excellent essay by Alexander Vilenkin:-http://inference-review.com/article/the-beginning-of-the-universe-"The question, however, remains whether the big bang was truly the beginning of the universe. A beginning in what? Caused by what? And determined by what, or whom? These questions have prompted physicists to make every attempt to avoid a cosmic beginning. -***-"The obstruction may be found in the Borde-Guth-Vilenkin (BGV) theorem. Loosely speaking, our theorem states that if the universe is, on average, expanding, then its history cannot be indefinitely continued into the past. More precisely, if the average expansion rate is positive along a given world line, or geodesic, then this geodesic must terminate after a finite amount of time. Different geodesics, different times. The important point is that the past history of the universe cannot be complete. -"The BGV theorem allows for some periods of contraction, but on average expansion wins. The volume of the universe increases with time. Inflation cannot be eternal and must have some sort of a beginning.-***-"What causes the universe to pop out of nothing? No cause is needed. If you have a radioactive atom, it will decay, and quantum mechanics gives the decay probability in a given interval of time, say, a minute. There is no reason why the atom decayed at this particular moment and not another. The process is completely random. No cause is needed for the quantum creation of the universe. -"The theory of quantum creation is no more than a speculative hypothesis. It is unclear how, or whether, it can be tested observationally. It is nonetheless the first attempt to formulate the problem of cosmic origin and to address it in a quantitative way. ( comment: again something from something, not true nothing)-***-"The answer to the question, “Did the universe have a beginning?” is, “It probably did.” We have no viable models of an eternal universe. The BGV theorem gives us reason to believe that such models simply cannot be constructed. -"When physicists or theologians ask me about the BGV theorem, I am happy to oblige. But my own view is that the theorem does not tell us anything about the existence of God. A deep mystery remains. The laws of physics that describe the quantum creation of the universe also describe its evolution. This seems to suggest that they have some independent existence. -"What exactly this means, we don't know. -"And why are these laws the ones we have? Why not other laws?-"We have no way to begin to address this mystery."-Comment: His problem is he can't accept God, but the universe had a beginning! Why?