Everything Everywhere All at Once is a creative movie released in 2022 playing with the possibility that I might not only exist in this universe, but in different versions of myself in many other universes… Could it be that there are other versions of myself that fulfil my true potential of saving the multiverse from destruction by an evil force, while in this universe I live the boring life of a laundromat warden like Evelyn Wang?
Even this short description demonstrates that the idea of a multiverse raises scientific questions (Is there evidence for other universes and what are these?), as well as theological questions (Did God create more than one universe? What is the role of mankind in a possible multiverse, and even more of Jesus Christ who reconciled all of the cosmos to God?).
So let us lean back a moment and consider this step by step. And if you find that too exhausting in this universe, just get into another universe where you can step out of your presuppositions and think with a little distance about the arguments…
A theology of the multiverse
Let us imagine for a moment that science has proven the existence of other universes. Would that mean that Christian faith and the Bible have been refuted?
One of my favourite verses in the Bible is Isaiah 55:9: ‘For as the heavens are higher than the earth, so are my ways higher than your ways and my thoughts than your thoughts’ (ESV). While some people started to doubt the Bible when it was discovered that our solar system is just one of trillions of other solar systems, in light of this verse, this discovery simply increases the greatness of God’s mind compared to ours.
Atheists concluded that this proves man’s insignificance and that we are not the crown of creation. However the value of human beings is not found in their relative size in the universe, but in God’s purpose, being made in God’s image. Does that change in view of there being many stars and solar systems?
Interestingly, Genesis 1 reads in Hebrew: 'In the beginning God created the heavens and the earth', where heavens, "shamayim", is in the plural. So speaking about multiverses theologically, they might just increase God’s power, creativity, and glory compared to our human limitations.
Of course, the story would change if there were other intelligent beings in other universes capable of moral decisions. The Bible is very clear that all the cosmos is reconciled to God through Jesus Christ (see Colossians 1:20).
Logically, there seem to be three alternatives:
1) These creatures might never have experienced a fall and, hence need not be redeemed. Rather, they could have been living in harmony with the Creator, praying for us to be redeemed back into holy fellowship. C.S. Lewis plays on this in his magnificent Perelandra trilogy.
2) These other beings could have also fallen from God and need to be redeemed, too. This could happen in two ways:
2a) Christ has also revealed himself to them in some way and explained how they can be saved through his sacrifice.
2b) As we explore space even more, we have to communicate the good news even to them, as famous George Verwer, founder of Operation Mobilisation, always loved to proclaim - tongue in cheek. However, our capability to communicate with other civilisation seems to be far too slow in view of the giant distances of the universe [1]. So I would not be very optimistic about this option.
However, we have not found any planet with positive evidence for the existence of life yet apart from ours. All this is interesting speculation.
In summary, there are versions of multiverses that are incompatible with the basic teachings of Christian faith, especially when it comes to the central role of Jesus Christ as redeemer, but other versions that are compatible, e.g. uninhabited worlds.
So yes, the existence and the quality of the multiverse does matter theologically, though the multiverse is not in direct competition with the existence of God, just as the gravitational law is not. However, we should not get lost in philosophical and theological speculations. There is another side to the debate: Is there evidence for the multiverse?
The science of the multiverse
It all began at the end of the 19th century with Austrian physicist Ludwig Boltzmann [2]. At that time, most scientists believed that the universe had an eternal past and hence an infinite number of universes (and inhabitants) could exist. Boltzmann realised that according to the second law of thermodynamics this poses the question of why our current universe is in such a low-entropy state, if there was an infinite past to it. But he realised that this law is statistical which means that there can always be entropy fluctuations creating regions of high order and low entropy allowing for life, simpler structures being much more frequent than complex structures. This leads to the famous Boltzmann brain or Boltzmann observer paradox which we can’t discuss here.
The Big Bang theory seemed to do away with the multiverse musings, as the universe only had a finite past. However, in the 70s, the discovery of the amazing fine-tuning of the physical constants of our universe initiated a rethink. Tiny changes in the constants (up to accuracies of 1:1060) of the fundamental parameters of the universe would lead to a universe in which no life would be possible.
Cosmologist Max Tegmark [3] compares this to a hotel in which you check-in and realise with surprise, "Oh, I have exactly the room number 1967 which incidentally is my birth year". But your surprise vanishes if you consider that there are lots of other rooms in which you would not have thought about your birth date. Hence, you can conclude from this very coincidence that there must be many other hotel rooms. For otherwise this room 1967 would not exist.
But wait a minute: the argument now sounds like this: Our universe is in a highly fine-tuned state. As a universe with these qualities is very improbable, there must be many other universes. Conclusive?
No, since, clearly, there could be other conclusions.
As Sir John Polkinghorne writes: 'Let us recognize these speculations for what they are. They are not physics, but in the strictest sense, metaphysics. There is no purely scientific reason to believe in an ensemble of universes. By construction these other worlds are unknowable by us. A possible explanation of equal intellectual respectability — and to my mind greater economy and elegance — would be that this one world is the way it is, because it is the creation of the will of a Creator who purposes that it should be so.' [4]
Hence, scientifically, the evidence for a multiverse is on very thin ice. We can’t observe these objects. If they suddenly disappeared, we would not even realise it. And the indirect argument from fine-tuning can be explained by purposeful design, arguably even better.
The mathematics of multiverses
Still, the multiverse continues to fascinate due to the beauty of the theory. Tegmark distinguishes four kinds of multiverse.
First, the regions within our own universe which we can’t observe, as their light has not yet had enough time to reach us since the beginning of the universe. The existence of these regions depends on the inflationary expansion (a very rapid exponential growth of space-time, shortly after the big bang) of the universe within a tiny fraction of the first second of this universe.
While mathematically this inflationary phase solves the problem of why our observable universe is flat and close to thermal equilibrium, we don’t have a clue about its mechanism, and empirically there is a big entropy problem similar to Boltzmann’s brain paradox. Sir Roger Penrose argued that it would be 10^10^123 times (a number larger than the amount of elementary particles in the universe) more probable that the region of low entropy which we can observe in our universe would be ten times smaller than we actually observe! This is close to a statistical refutation…
Second, Tegmark claims that there are billions of other universes with probably different constants, most of them uninhabitable. This is pure speculation and can be explained otherwise, as Polkinghorne argued above.
Third, there are the so-called Everett universes, which are derived from quantum mechanics. Quantum mechanics tells us that the state of a microcosmic system has the potential of different outcomes with different probabilities. When the system is measured or observed, only one possibility is actualised, while the potentiality of the others is lost. Physicists call this the “breakdown of the wave function”. What a pity! Couldn’t it be that the other possibilities are also actualised in a different universe? Couldn‘t it be, that, at every decision (and “measurement”) we make, ALL possibilities are actualised?
Well, it could be. But think about the growing number of universes every second, if all possibilities of all 1080 elementary particles come true in different universes. What about energy conservation? And what would it mean that “physical persons” would split up into different universes? Who am I in this bouquet of flourishing universes?
An equally valid interpretation of quantum mechanics would be that the universe was created with a certain set of possibilities which can and will be actualised in the course of history, while a lot of possibilities and potentialities can get lost on the way. Isn’t that close to the way the Bible depicts history?
Fourth, Max Tegmark says that the deepest level of multiverse is the mathematical structure of string theory. String theory seems to explain fundamental symmetries of our universe, including its fine-tuned constants, by postulating that all particles are simply states of vibrating 11-dimensional strings (9+1 space dimensions and 1 time dimension). However, string theory can end up in about 10500 different kinds of universes. And the testable predictions are on the scale of about 10^-30 m which is a million billion times smaller than an atomic nucleus (10^-15 m) or a billion times smaller than the radius of the electron (about 10^-18 -10^-22 m). Still string theory has a mathematical appeal, as it unites quantum mechanics and gravity in a beautiful way, as far as mathematicians define “beautiful”.
The interesting thing about string theory is: if it was true, it would provide ultimate evidence that the material universe exhibits an underlying immaterial logical “Platonic” structure. But where would this logical structure come from? And as Stephen Hawking wrote in A Brief History of Time: ‘What is it that breathes fire into the equations and makes a universe for them to describe?’ Numbers do not call a universe into existence. Could it be that this would rather point to a creative mind of brilliant rationality and creative power?
Conclusion: So is there a multiverse and does it matter?
Theologically, we can say that God could have created more than one universe, as long as Christ’s role as redeemer of all of creation is not affected. The multiverse is not a competing hypothesis to the biblical God.
Scientifically, we can say that the existence of a multiverse would be very desirable to provide a naturalistic explanation for the fine-tuning of our universe. While it is possible in principle, there is no hard empirical evidence, the large problem of entropy, a lot of speculation, and other valid explanations.
Mathematically, string theory would imply a giant host of universes and would explain a lot of contingencies in our current scientific theories. But as a beautiful mathematical theory (without empirical evidence yet), it would point to a beautifully brilliant mathematical mind who had the universe in mind with a structure that would allow mankind’s existence and scientific research.
Further reading
On the multiverse and string theory:
Max Tegmark, Our Mathematical Universe (2014)
Brian Greene, The Elegant Universe (1999)
Christian interpretations:
John Lennox, Cosmic Chemistry (2021)
John Polkinghorne, One World (1986)
G.F. Lewis, L. Barnes, A Fortunate Universe (2016) (actually a dialogue between a naturalist and a Christian on fine-tuning with a very helpful chapter on the multiverse, ch. 7)
Hugh Ross, Beyond the Cosmos (2017, 3rd edition)
References
[1] For specialists: read about the so called "Fermi paradox“
[2] G.F. Lewis, L. Barnes, A Fortunate Universe (2016), ch. 7, p. 313ff.
[3] https://www.spektrum.de/magazin/parallel-universen/830044 , cf. Max Tegmark, The Mathematical Universe (2014)
[4] John Polkinghorne, One World (1986), p. 80
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