Worlds Without End: The Many Lives of the Multiverse,

Columbia U. Press
, 2014. $28.95 (343 pp.). ISBN 978-0-231-15662-2

God and the Multiverse: Humanity’s Expanding View of the Cosmos,

Victor J.
Prometheus Books
, 2014. $26.00 (447 pp.). ISBN 978-1-61614-970-3

The multiverse has recently become a popular topic in science and literature. A recent Google search for “multiverse” returned more than 7.7 million results. A similar search on yielded 3264 items, among them 1213 books, including the two under review: Worlds Without End: The Many Lives of the Multiverse by Mary-Jane Rubenstein and God and the Multiverse: Humanity’s Expanding View of the Cosmos by Victor Stenger (who died in August 2014). They provide nice complementary accounts of multiverse ideas, though neither gives an adequate treatment of the current science in the field.

Worlds Without End is by far the more scholarly account: Its 961 endnotes contain thousands of references spanning two millennia. Rubenstein, an associate professor of religion at Wesleyan University in Connecticut, does a fine job covering the roots of the multiverse idea and includes such tidbits as Plutarch’s report that “[H]aving heard Anaxarchus on the infinity of the kosmoi, Alexander [the Great] wept and, when his companions asked what was the matter, he said, ‘Is it not worthy of tears that, when there are infinitely many kosmoi, we are not masters of one?’”

Rubenstein’s balanced account reviews the many arguments for and against the multiverse and the philosophical and theological implications of those arguments. For example, near the end of the book, she discusses what Friedrich Nietzsche calls “the self-overcoming of Christianity.” As Rubenstein interprets this, “Christianity produces modern science, in a staggering gesture of self-sabotage, as its consummation and its destruction.” But Nietzsche went on to claim that “all great things bring about their own destruction through an act of self-overcoming,” which prompts Rubenstein to wonder, “If science can be regarded as the self-overcoming of a particular form of religion, might multiverse cosmologies be something like the self-overcoming of science? Might they mark the end of the fantasy that ‘science’ has wrested itself free from ‘religion,’ ‘objectivity’ free from subjectivity, and matter free from meaning?”

I do agree with Rubenstein’s final “hunch” that “the shape, number, and character of the cosmos might well depend on the question we ask it.” Even what might be called a multiverse—different physical realms with different effective physical constants, different particles and fields, and perhaps even different spacetime dimensions (or no spacetime at all)—could be regarded as one single quantum state and, hence, as one single universe.

One weakness of Rubenstein’s account is that she does not fully grasp the scientific details in some recent multiverse proposals, and sometimes the scientists she relies on are not the most qualified in the field. She also makes some mathematical mistakes, such as in thinking that Immanuel Kant’s infinite universe, with worlds fanning out from the center but becoming farther and farther apart, would not have an infinite number of worlds. Also, on page 271, she conflates Newton’s gravitational constant G with g, the acceleration of gravity on Earth. But if one seeks a scholarly account of the main ideas rather than of the detailed science, then Worlds Without End is excellent.

By contrast, in God and the Multiverse, only the last two chapters out of 16 offer a significant discussion of the multiverse, and only the final one deals much with questions of God’s existence. The vast majority of the book is a highly readable, popular-level account of cosmology’s development.

The author, Stenger, was an emeritus professor of physics and astronomy at the University of Hawaii. His mainly experimental-physics background put him in a somewhat better position than Rubenstein to discuss the most recent ideas, but he, too, was not an expert on multiverse theories and seems to have had some mistaken ideas about them and about several related concepts of theoretical physics.

For example, Stenger was rightly impressed with the symmetry principles of modern physics, but he expressed the erroneous view that such principles are necessary—and then he overlooked the apparent paradox that those supposed necessities are spontaneously broken “by accident.” In fact, logically, the laws of physics and of the quantum state need not have any symmetries at all. And neither their existence nor their absence would support Stenger’s claim that “no lawgiver was involved, natural or supernatural.”

Stenger also claims that “the multiverse provides a very simple, purely natural, solution to the fine-tuning problem”—the “problem” being that life seems possible only in a small fraction of the possible parameter space, and yet the actual parameters do exist in the small region that allows life. But most of the time he argues that the parameters aren’t really fine-tuned at all. I agree with some of his specific arguments and disagree with others, but I endorse one of his conclusions: Arguments for fine tuning do not prove the existence of God, since the fine tuning could be explained by a suitable multiverse even if God did not exist.

On the other hand, I don’t buy his argument that “all major religious traditions are likely to have great difficulty reconciling their concept of a creator god with a multiverse that is eternal and uncreated.” It is an unproved assumption that our multiverse, if our universe is indeed part of a multiverse, is either eternal or uncreated—and of course God could have created an eternal multiverse.

The treatment of the titular subjects in God and the Multiverse is highly superficial. But the title of the book and the arguments that I find objectionable don’t reflect the main content of the book. The principal story, as opposed to the advertised one, is a popular-level discussion of scientific cosmology and its development. Stenger tells that story very well.

Don Page studies black holes and quantum cosmology at the University of Alberta in Canada. He has written several scientific papers on the multiverse measure problem and on the topic of God and the multiverse.