Wednesday, March 15, 2017
A Universe From Nothing?
First, I'd like to provide a short synopsis of the major conclusions in the book. Like many other books that ultimately deal with issues concerning cosmic origins (e.g. Stephen Hawking's A Brief History of Time), Krauss's book has a nice discussion and synopsis about some of the discoveries of modern science. He points out that at one time scientists would have considered a vacuum in deep space to be a perfect definition of nothing. However, we now know that the space-time fabric of our universe is made up of a quantum vacuum that is quite different from what was previously conceived. The elementary particles and forces in the universe are described by a relativistic quantum field theory (QFT). Within the framework of QFT, our quantum vacuum can be thought of as a bubbling sea of many different kinds of fields. These fields have the potential of creating particles out of nothing. For instance, an excitation, or perturbation, of an electron field can produce an electron. Within QFT a particle and its antiparticle (e.g. an electron and a positron) can come into existence from "nothing" where the "nothing" is the underlying quantum vacuum. Except for near a strong gravitational field like a black hole, these particles from nothing will quickly annihilate each other and cease to exist, and are thus called "virtual" particles. Everything described to this point is well known and well tested science, and Krauss gives a nice description of this fascinating science.
However, at this point in the book, Krauss deviates from known science and begins to speculate about how the universe may behave based on our lack of understanding of any quantum theory of gravity as discussed in a previous post. He proposes that, just as our previous definition of nothing turned out to have the potential for creating particles from the "nothingness" of the vacuum, maybe there is an analogous underlying reality in which virtual space-time universes like ours can be created from nothing. Just as a space-time quantum vacuum can create particles, maybe another type of unknown "nothing" has the potential to create space-time universes. Thus, Krauss's "nothing" is not the underlying space-time structure of our universe, but a broader definition of nothing that has the potential of spawning universes. Krauss's proposal raises a number of questions that I want to try to answer. First, is Krauss's definition of nothing really nothing? Second, is Krauss's theory scientific and does it really propose anything new? Finally, if Krauss's theory were found to be true, what affect would it have on arguments for theism, particularly regarding the Christian idea of God?
Since the original publication of this book, Krauss has been universally criticized for his use of the word "nothing." Just about every scientist and philosopher has argued that Krauss's definition of nothing is not nothing but something akin to the underlying structure of our universe. Though it is definitely not the same as our known space-time quantum vacuum universe, an environment that can spawn virtual universes in the same way our universe can spawn virtual particles can hardly be called "nothing." Krauss claims that even the laws of physics that we know would be initiated with our universe from nothing, but he doesn't seem to recognize the fact that his ideas still require some set of physical laws to pre-exist in order to bring our universe into existence. The criticism of Krauss's terminology has been so overwhelming that he has tried to address his critics in the preface to later editions of his book. However, his response reads like that of a child who continually insists that he didn't eat any cookies even though there are crumbs all over his face. Everyone else knows the reality of the situation, but the child claims it isn't so. Although Krauss's "nothing" would expand our understanding of what underlies the reality of our universe, just as a quantum vacuum expanded our understanding of what really comprises the vacuum of space, it would not qualify as no-thing as most scientists, philosophers, or other humans would use the term.
Like many ideas about the origin of our universe, Krauss's is not based on any known science but rather only on what is not known. Because there is no theory of quantum gravity, we do not know what laws of physics governed the first 10-35 seconds or so of our universe or what laws, if any, existed beforehand. Krauss is appealing to our ignorance to propose a solution that he believes removes the need for any act of God to begin our universe. As I have pointed out in previous posts, everything that we do know about the origin of our universe seems to indicate it had an actual transcendent cause consistent with the Christian God. Those who want to remove God from the equation must appeal to what is not known, rather than to what is known. I call this an "atheism of the gaps" and it is exactly what Krauss is doing in A Universe From Nothing. Everything we do know about the origin and design of the universe looks a lot like there is a creator God, so to remove God, any proposal must appeal to what is not known. It is ironic that atheists have for years claimed that Christians appeal to a god of the gaps to explain things that are not known, but many of the current arguments from atheists against God can only appeal to gaps in our understanding. Does Krauss's suggestion to fill in the gaps postulate anything new that has not been proposed by others before him? In essence, not really. There have been many proposals that claim our universe started from some kind of quantum fluctuation. Krauss just proposes a particular kind of fluctuation and one that currently has no basis in any known science. As the physicist S. I. Kohli concluded, "many of the claims are not supported in full by modern general relativity theory or quantum field theory in curved spacetime"1. This is not science since science is based on observations and measurements. It is simply speculation based on philosophical naturalism.
Finally, suppose we were to somehow confirm that Krauss's speculation were true? Would that remove God from the discussion about the origin of our universe. Would there be no need for God? The obvious answer to that question can be inferred from the discussion in my previous post in which I reasoned that God's usual method of revealing himself in nature is through natural means. If there were a natural mechanism that brought this universe into existence, we have not removed God as the cause, but instead discovered the means by which he created our universe. In fact, Krauss's proposal basically agrees with the Christian view of the origin of our universe. Since Krauss's "nothing" is clearly not no-thing, Krauss is actually claiming that this universe came into existence through an external mechanism that can spawn universes from nothing. Hmm, isn't that exactly what Christians would say; that this universe was spawned from nothing by a mechanism that came from God's creative character? I don't know what mechanism God used to create this universe, and whether it was through some "natural" or "supernatural" means. However, I do know that he spawned this universe "in the beginning" which would be in complete agreement with Krauss's proposal.
A Universe From Nothing is a nice treatise on modern physics for much of the book. But the final proposal adds little to previous speculation about the origin of the universe, is not based on any confirmed scientific facts, and does nothing to remove the need for an ultimate cause.
1Ikjyot Singh Kohli (2014). "Comments On: A Universe From Nothing". arXiv:1405.6091.