He begins by pointing out that the history of science has been one of trying to show how all phenomena are explicable in terms of fundamental principles and physical causes, but now that's all in jeopardy with the discovery of the incredibly precise values of many of the fundamental cosmic parameters and forces:
Dramatic developments in cosmological findings and thought have led some of the world’s premier physicists to propose that our universe is only one of an enormous number of universes with wildly varying properties, and that some of the most basic features of our particular universe are indeed mere accidents—a random throw of the cosmic dice. In which case, there is no hope of ever explaining our universe’s features in terms of fundamental causes and principles.So why is the multiverse attractive to some scientists? Consider some highly improbable event like being dealt a royal flush in cards. The odds against it are very high, but if you're dealt enough hands eventually one of them will be a royal flush.
It is perhaps impossible to say how far apart the different universes may be, or whether they exist simultaneously in time. Some may have stars and galaxies like ours. Some may not. Some may be finite in size. Some may be infinite. Physicists call the totality of universes the “multiverse.”
Likewise with universes. If a near infinite number of different universes are somehow generated, then all possible worlds, no matter how vanishingly improbable any particular world may be, will eventually be produced. Thus, although it is exceedingly unlikely that a single universe with the precision of ours would have just happened, if there are an infinite number of different worlds then one like ours becomes not only probable but inevitable:
...the multiverse idea does explain one aspect of our universe that has unsettled some scientists for years: according to various calculations, if the values of some of the fundamental parameters of our universe were a little larger or a little smaller, life could not have arisen.There are only two answers currently on the table: Either the universe was deliberately designed by an intelligent agent or there are an infinite number of different universes, a multiverse:
For example, if the nuclear force were a few percentage points stronger than it actually is, then all the hydrogen atoms in the infant universe would have fused with other hydrogen atoms to make helium, and there would be no hydrogen left. No hydrogen means no water....On the other hand, if the nuclear force were substantially weaker than what it actually is, then the complex atoms needed for biology could not hold together.
As another example, if the relationship between the strengths of the gravitational force and the electromagnetic force were not close to what it is, then the cosmos would not harbor any stars that explode and spew out life-supporting chemical elements into space or any other stars that form planets. Both kinds of stars are required for the emergence of life. The strengths of the basic forces and certain other fundamental parameters in our universe appear to be “fine-tuned” to allow the existence of life.
If such conclusions are correct, the great question, of course, is why these fundamental parameters happen to lie within the range needed for life. Does the universe care about life?
Intelligent design, however, is an answer to fine-tuning that does not appeal to most scientists. The multiverse offers another explanation. If there are countless different universes with different properties—for example, some with nuclear forces much stronger than in our universe and some with nuclear forces much weaker—then some of those universes will allow the emergence of life and some will not....In other words, the multiverse is a hypothesis to which scientists resort so they don't have to accept the metaphysical implications of an intelligent design:
From the huge range of possible universes predicted by the theories, the fraction of universes with life is undoubtedly small. But that doesn’t matter. We live in one of the universes that permits life because otherwise we wouldn’t be here to ask the question.
The multiverse offers an explanation to the fine-tuning conundrum that does not require the presence of a Designer. As Steven Weinberg says: “Over many centuries science has weakened the hold of religion, not by disproving the existence of God but by invalidating arguments for God based on what we observe in the natural world. The multiverse idea offers an explanation of why we find ourselves in a universe favorable to life that does not rely on the benevolence of a creator, and so if correct will leave still less support for religion.”It's noteworthy, I think that in this entire essay Lightman never mentions how exquisitely precise the values of these cosmic parameters are. It's as if he realizes that if he did, it would only lend credence in his readers' minds to the designer hypothesis.
The most striking example of fine-tuning, and one that practically demands the multiverse to explain it, is the unexpected detection of what scientists call dark energy.The dark energy is tuned to a value of something like one part in 10^120, an inconceivably fine tolerance (A stack of dimes reaching from the earth to the sun would consist of approximately 10^14 dimes). If the dark energy value were different from what it is by just one part in 10^120, the universe, if it existed at all, would be inhospitable to life.
But does the dark energy example "demand" the multiverse as Lightman claims? Only if one assumes a priori that no other explanation is correct, but such an assumption is hardly warranted, especially since the alternative, intelligent design, is discounted for no reason other than it's philosophically repugnant to atheistic naturalists.
Even so, for the naturalist who embraces the multiverse, there are numerous ironies lying about.
In the first place the multiverse hypothesis is metaphysics, not science. It's the consequence of the philosophical assumption that all phenomena are reducible to physical processes and forces and that there is no supernatural mind. This is emphatically not something that science has demonstrated, contrary to what Weinberg seems to think. Nor can science ever empirically demonstrate, even in principle, that there is a multiverse.
Secondly, the multiverse undercuts naturalists' objections to miracles. If every conceivable universe exists then there are universes in which, no matter how unlikely it may be, a man is born to a virgin. There are also universes in which water is changed to wine, and in which a man returns to life after being dead for three days. Indeed, there are worlds in which all of these highly improbable events are accomplished in the life of one man, and ours might well be one such world.
Thirdly, the multiverse makes the existence of a designer virtually inevitable. If every possible world exists then, since it's certainly possible that there's a world that's designed by an intelligent agent, there must in fact be at least one such world. Our world could be it, but whether it is or isn't the point is that a designer capable of creating universes must exist.
So, if atheists think they've escaped having to accept the existence of a cosmic designer by positing an infinite series of worlds they're deluding themselves. If there is no multiverse then there is an intelligent designer of the universe. If there is a multiverse then there is an intelligent designer of at least one universe.
Either way, there exists an extraordinarily intelligent, unimaginably powerful, transcendent agent. Who might such a being be?