Paul Davies, PhD, English physicist & professor, 1946-
“In spite of the power of the many-universes theory to account for what would otherwise be considered remarkably special facts about nature, the theory faces a number of serious objections. The first of these I have already discussed in chapter 7, which is that it flies in the face of Occam’s razor, by introducing vast (indeed infinite) complexity to explain the regularities of just one universe. I find this ‘blunderbuss’ approach to explaining the specialness of our universe scientifically questionable. There is also the obvious problem that the theory can explain only those aspects of nature that are relevant to the existence of conscious life; otherwise there is no selection mechanism. Many of the examples I have given for design, such as the ingenuity and the unity of particle physics, have little obvious connection with biology. Remember that it is not sufficient for the feature concerned simply to be relevant to biology, it has to be crucial to its actual prevalence.
“Another point which is often glossed over is that, in all of the many-universe theories that derive from real physics (as opposed to simply fantasizing about the existence of other worlds), the laws of physics are the same in all the worlds. The selection of universes on offer is restricted to those that are physically possible, as opposed to those that can be imagined. There will be many more universes that are logically possible but contradict the laws of physics. In the example of the electron which can have either spin-up or -down, both worlds contain an electron with the same electric charge, obeying the same laws of electromagnetism, etc. So, although such many-universe theories might provide a selection of alternative states of the world, they cannot provide a selection of laws. It is true that the distinction between features of nature that owe their existence to a true underlying law, and those that can be attributed to the choice of state, is not always clear...
“It is therefore not possible, as some physicists have suggested, to account for nature’s lawfulness this way. Might it not be possible, however, to extend the many-universes idea to encompass different laws too? There is no logical objection to this, although there is no scientific justification for it either. But suppose one does entertain the existence of an even vaster stack of alternative realities for which any notion of law, order, or regularity is absent. Here chaos rules totally. The behavior of these worlds is entirely random. Well, just as a monkey tinkering with a typewriter will eventually type Shakespeare, so somewhere among that vast stack of realities will be worlds that are partially ordered, just by chance. Anthropic reasoning then leads us to conclude that any given observer will perceive an ordered world, mindbogglingly rare though such a world may be relative to its chaotic competitors. Would this account for our world?
“I think the answer is clearly no...”
— Paul Davies, The Mind of God, Touchstone, 1992 p218-220
“Not everybody is happy with the many-universes theory. To postulate an infinity of unseen and unseeable universes just to explain the one we do see seems like a case of excess baggage carried to the extreme. It is simpler to postulate one unseen God. This is the conclusion also reached by [Richard] Swinburne:
“’The postulation of God is the postulation of one entity of a simple kind... The postulation of the actual existence of an infinite number of worlds, between them exhausting all the logical possibilities...is to postulate complexity and non-prearranged coincidence of infinite dimensions beyond rational belief.’
“Scientifically the many-universes theory is unsatisfactory because it could never be falsified: what discoveries would lead a many-worlder to change her/his mind? What can you say to convince somebody who denies the existence of these other worlds? Worse still, you can use many worlds to explain anything at all. Science becomes redundant. The regularities of nature would need no further investigation, because they could simply be explained as a selection effect, needed to keep us alive and observing. Furthermore, there is something philosophically unsatisfactory about all those universes that go unobserved. To paraphrase [Roger] Penrose, what does it mean to say that something exists that can never in principle be observed?...”
— Paul Davies, The Mind of God, Touchstone, 1992 p190-191
“...It must be said, however, that the [quantum multiverse theory] is not without its critics, some of whom (e.g., Roger Penrose) challenge the claim that we would not notice the splitting.”
— Paul Davies, The Mind of God, Touchstone, 1992 p217
“It is hard to resist the impression that the present structure of the universe, apparently so sensitive to minor alterations in numbers, has been rather carefully thought out. Such a conclusion can, of course, be only subjective. In the end it boils down to a question of belief. Is it easier to believe in a cosmic designer then the multiplicity of universes necessary for the weak anthropic principle to work?... if we cannot visit the other universes or experience them directly, their possible existence must remain just as much a matter of faith as belief God... the seemingly miraculous concurrence of numerical values that nature has assigned to her fundamental constants must remain the most compelling evidence for an element of cosmic design.”
— Paul Davies, PhD, God and the New Physics, Simon & Schuster, 1983 p189
“My conclusion is that the many-universes theory can at best explain only a limited range of features, and then only if one appends some metaphysical assumptions that seem no less extravagant than design. In the end, Occam’s razor compels me to put my money on design, but, as always in matters of metaphysics, the decision is largely a matter of taste rather than scientific judgment. It is worth noting, however, that it is perfectly consistent to believe in both an ensemble of universes and a designer God. Indeed, as I have discussed, plausible world-ensemble theories still require a measure of explanation, such as the lawlike character of the universes and why there exists a world-ensemble in the first place...”
— Paul Davies, The Mind of God, Touchstone, 1992 p220
Robin Collins, PhD, American philosopher
“My wife and I have a bread-making machine... To make edible bread, we first needed this well-designed machine that had the right circuity, the right heating element, the right timer, and so forth. Then we had to put in the right ingredients in the right proportions and in the right order–water, milk, flour, shortening, salt, sugar, yeast. The flour had to have the right amount of a protein substance called gluten, or else it would need to be added. Everything has to be just right to produce a load of bread–otherwise, you get what looks like a burnt hockey puck.
“Now, let's face it: a universe is far more complex than a load of bread. My point is that if a bread machine requires certain specific parameters to be set in order to create bread, then there has to be a highly designed mechanism or process to produce functional universes. In other words, regardless of which multiple-universe theory you use, in every case you'd need a ‘many-universes generator’–and it would require the right structure, the right mechanism, and the right ingredients to churn out new universes.”
— Robin Collins, PhD, (quoted by Lee Strobel), A Case for a Creator, Zondervan, 2004 p149
“It’s highly unlikely that such a universe-generating system would have all the right components and ingredients in place by random chance, just like random chance can’t account for how a bread-maker produces loaves of edible bread. So if a many-universe-generating system exists, it would be best explained by design.”
― Robin Collins, PhD, (quoted by Lee Strobel), A Case for a Creator, Zondervan, 2004 p152
Robin Le Poidevin, British professor of metaphysics, 1962-
“So the atheist can offer an alternative explanation of fine-tuning. Which is the more credible hypothesis, God or the multiverse? That depends on your point of view. On the one hand, it might seem less extravagant to posit the existence of just one (admittedly extraordinary) object, namely God, than to posit an enormous number of objects, namely universes. On the other hand, that one object is something very different from anything else we are aware of, whereas the multiverse just contains lots of universes like (or perhaps not so very like) the one we know exists. So we have something of a stalemate between the theist and atheist.”
— Robin Le Poidevin, Agnosticism: A Very Short Introduction, Oxford University Press, 2020 p62-63