Big Bang for beginners-16: Concluding thoughts


(My latest book God vs. Darwin: The War Between Evolution and Creationism in the Classroom has just been released and is now available through the usual outlets. You can order it from Amazon, Barnes and Noble, the publishers Rowman & Littlefield, and also through your local bookstores. For more on the book, see here. You can also listen to the podcast of the interview on WCPN 90.3 about the book.)

For previous posts in this series, see here.

As is often the case when I am writing about something, I get a little carried away and the series seems to go on forever. But we have actually reached the last post in this series where I want to look at the broader implications of what all these scientific advances with the Big Bang theory means, particularly for religion. I hope that those who stuck with me through to the bitter end have obtained a deeper understanding than they had before.

Religious apologists often argue that the only or simplest solution to the question of what existed before the Big Bang and what caused the universe to come into being is god. They are wrong on both counts.

It is not the only solution because there is nothing deeply mysterious about the time at which the Big Bang occurred. It has been assigned the value of zero time but that choice is arbitrary, just as our calendar is arbitrarily numbered according to the legend of Jesus’s birth. We could just as easily have fixed the zero at some other time and said that the Big Bang occurred in the year 4760 or -9384.

There are theories about what could have existed before the Big Bang (see Has Science Found God? by particle astrophysicist Victor Stenger, chapter seven: The Other Side of Time) just as there are theories about how our universe came into being (chapter eight: The Laws of the Void). For example, one version of the multiverse theory says that as universes evolve, one can have small regions ‘pinching off’ (via the same kind of quantum fluctuation that created our universe) to create new universes. These things could have been going on forever and what we call the ‘beginning of time’ is simply the beginning of ‘our’ time, when our particular universe came into being. There is nothing more special to it than that.

It is true that these are more speculative theories than what we usually work with in science and will need more work and data before we can transform them into viable theories. When workable theories come into being, they usually bring along with them suggestions of what to measure and how to measure them to see if the theory has any merit. But the important thing to bear in mind is that our present universe is not some deeply mysterious entity whose existence and properties are baffling. As Stenger points out, there is a lot we do know already and all of it undermines the need for any supernatural agency:

We have seen that zero external energy was required to produce the mass and energy of the universe. We have seen that order can spontaneously arise from disorder. We have seen that complexity can evolve from simplicity. We have seen that time has no fundamental arrow, and so the very concept of cosmic beginnings and causal creation are problematical. No known scientific principles are necessarily violated in a model of our universe that is causally self-contained, in which everything that happens, happens within. (p. 188, my italics)

The origin of the universe is not a deep mystery. It is simply a puzzle that is already being scientifically investigated. What might have existed before the Big Bang is also being investigated, as is the question of why it has its current properties. So the idea that god is the only way to explain these things is simply incorrect. God is simply unnecessary.

The argument that god is to be preferred as an explanation because it is a simpler solution than these fancy-schmancy scientific theories is also fallacious. Religious people think that just because god is a three-letter word and the concept of god is a familiar one, that therefore it constitutes a ‘simple’ explanation. It is far from it. You can see why if, instead of using the short word ‘god’, someone gave his or her ‘solution’ to any scientific problem (such as the origin of the universe and life) by saying:

First we must postulate the existence of an complex, intelligent, omnipotent, omniscient, and everlasting entity that either exists throughout all of our universe or outside of it, created all the matter and laws that govern their behavior and yet can overrule the laws of science that it created on a whim, is made up of a totally undetectable substance, and is able to act in ways that seem indistinguishable from the working of natural laws.

Second, we postulate that this entity then did whatever we cannot explain, but that we don’t know how.

That’s not much of an explanation, is it? It is definitely not ‘simple’. It would be like explaining to a child that the reason the sun ‘moves’ across the sky during the day is because there is a huge man (whom we cannot see because the sun is too bright) whose job it is to push it along its path. It is a ‘simple’ solution in the sense that a child might understand it because ‘man’ is a simple three-letter word and the basic concepts of ‘man’ and ‘push’ are already familiar to the child. But it is not a solution at all in the scientific sense because it does not explain how a man could be up there and act this way. It merely shifts the problem to a different and more difficult level. Saying that god always existed and does not require an explanation for his own origins would be like telling the child that the huge invisible man always existed and needs no further explanation. Only a naïve and trusting child would believe such nonsense.

As Richard Dawkins keeps saying, invoking the existence of a highly complex entity by fiat raises far more problems than it solves. Real solutions to problems require explaining how complex phenomena arise using simpler entities and concepts. This is what the Big Bang theory does for the universe as a whole, just as Darwin’s theory of evolution by natural selection does for life. Starting with a simple mixture of quarks, gluons, electrons, and a few other particles in a highly dense and almost perfectly uniform gas, we can now understand how the complex structure of the universe came about.

All this has been done using natural laws and physical entities. Those who try to explain all this by concocting a god that does not contradict modern science always end up with something that is superfluous. As physicist Steven Weinberg says, “The more we refine our understanding of God to make the concept plausible, the more it seems pointless.” Religious people can postulate a god if they wish but it would be on the same level as postulating the existence of unicorns or fairies or the Flying Spaghetti Monster or the man pushing the sun.

There are still important unexplained questions as well as questions of detail to be worked out about how the universe and life came about. It is exciting when there are big open questions to investigate because they hold the promise of new scientific discoveries. But what we can say now with considerable confidence is that the nature of physical reality shows no sign whatsoever that we need to invoke a transcendental being or supernatural forces in order to explain anything.

According to modern cosmological theories, universes are being created out of vacuum fluctuations all the time and such events are consistent with all the known laws of science. Occasionally, one will be created that will have the necessary conditions to produce sentient beings like us. As Edward Tryon said back in 1973 in his paper Is the Universe a Vacuum Fluctuation? (Nature, vol. 246, p. 396-397, 14 December 1973.):

[M]y answer lies in the principle of biological selection, which states that any Universe in which sentient beings find themselves is necessarily hospitable to sentient beings. I do not claim that universes like ours occur frequently, merely that the expected frequency is non-zero. Vacuum fluctuations on the scale of our Universe are probably quite rare. The logic of the situation dictates, however, that observers always find themselves in universes capable of generating life, and such universes are impressively large.

In response to the assertion that though we might know how the universe came into being, we do not understand why, Tryon responds with a marvelously laconic understatement: “In answer to the question of why it happened, I offer the modest proposal that our Universe is simply one of those things which happen from time to time.”

While we can look at the magnificence of the universe with a sense of awe, there is nothing about the existence of life and the universe that looks like it has an externally imposed meaning.

POST SCRIPT: The Galaxy Song

Although I posted this recently, I think that this clip from Monty Python and the Meaning of Life is a good way to end this series of posts because it captures the sense of wonder at the amazing universe we live in. I particularly like the line, “Remember when you’re feeling very small and insecure, how amazingly unlikely is your birth” because it reminds me how lucky we are to be alive and able to appreciate it. Why would anyone want anything more?

Comments

  1. Bill says

    Thanks for this Mano, a very thought provoking and educational series. Greatly appreciate it.

  2. jaybee says

    I have had this series bookmarked for a long time and have just now gotten around to reading it all over the past few evenings. Thanks for writing it! I think the biggest single insight I’ve learned is that of the fundamental role of expansion of space. Of course I knew of it, but I thought it was just part of the mix. I was still thinking of the big bang in terms of a kinematic explosion, rather than the (remarkably rapid) expansion of space.

    On the other hand, I recently read “From Eternity to Here” by Sean Carroll, where the entire focus of the book is wrestling with the issue of entropy. Mainly, the key problem is to explain how entropy could have just coincidentally been so low at the moment of the big bang. It is hard for me to reconcile why Sean Carroll thought it is a big and unsolved problem, yet your explanation (that an expanding universe allows for increasing entropy, thus waste heat once again becomes useful heat) is compellingly simple.

  3. Mano Singham says

    Carroll has a point. And since he is a far greater expert on these issues than I am, I would defer to him. The question of entropy is very tricky (it depends among other things on whether one is talking about the entropy of a volume that is expanding or the entropy of all space) and it depends on how he is using the term.

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