I would like to thank Prof Yasunori Nomura, director of the Berkeley Centre for Theoretical Physics who read over a draft of this manuscript and provided valuable feedback. Any mistakes are still my own though.
Due to my cosmology YouTube series Before the Big Bang, I have been fortunate to be on the Unbelievable? podcast three times. I say fortunate because Justin Brierley is a charming host; it was a great pleasure to be discussing important issues in such a fair and balanced way. In his recent book though, Unbelievable, any attempt at impartiality is thrown aside and Justin makes his case for the truth of Christianity. The subtitle of the book is why after ten years of talking to atheists I’m still a Christian implies that Justin has listened to what atheists have to say and has good reasons to reject their arguments. But does Justin really have powerful argument for the Christian God? In this chapter I will examine Justin’s argument that God provides a convincing explanation for our existence.
Let’s start with the claim that the increasing complexity of life on Earth seems to be in conflict with the second law of thermodynamics. The law says roughly that disorder tends to increase over time in a closed system. But life’s complexity seems to defy that hence God is needed to intervene.
But there is no conflict with life and the second law. Consider an example given by cosmologist Sean Carroll in his book The Big Picture  . Carroll asks us to picture a glass of coffee with some cream poured in. (If you are English like me, you might think of milk and tea.) Neither the starting state with the cream at the top nor the end state with the cream and coffee blended are especially complicated. The complexity is in fact highest in the middle, when the coffee and the cream are making interesting structures. We could measure the complexity by taking pictures of the cup and comparing the size of the compressed file. Now all the way through this mixing, the second law is not violated but complexity starts off low, increases and then falls back down. This is not untypical of what entropic systems do. Increasing entropy is not equivalent to declining complexity, at least not in the short term.
The early universe similarly starts off as a simple soup of matter and radiation, complexity then rises as galaxies and solar systems form and then complexity falls back down. None of this violates the second law. There is plenty of room for some subsystems to decrease their local entropy as long as global entropy is increasing. As Carroll states “The appearance of complexity isn’t just compatible with increasing entropy, it relies on it” .
One should also point out that the Earth itself is not a closed system. It receives low entropy photons from the sun and this is enough to allow complex life to form. We expel those photons back into space, these expelled photons have higher entropy and life uses that transformation, so again no conflict with the second law applies.
Justin goes onto to The Kalam cosmological argument, arguing everything that begins to exist has a cause, the universe began to exist and so the universe must have a cause; which must be God.
When we think of causes though, we always do so in the context of time. We could say all events that have causes have prior moments in time. If the universe had a beginning then there was no prior moment of time and hence we have no right to demand there must be some prior cause. Causality may also be a consequence of the laws of physics and the arrow of time. If we had some state with no space or time, no laws of physics and no arrow of time, are we really in a position to demand there must still be a cause?
Another problem is that causality has been questioned by a number of philosophers and physicists. Quantum mechanics certainly raises the possibility of a breakdown of cause and effect. Alex Vilenkin is a cosmologist often quoted by theists who have been on Justin’s show. Vilenkin claimed to have proved the universe must have had a beginning (more of that later) but he also claimed “If there was nothing before the universe popped out, then what could have caused the tunneling? Remarkably, the answer is that no cause is required. In classical physics, causality dictates what happens from one moment to the next, but in quantum mechanics the behavior of physical objects is inherently unpredictable and some quantum processes have no cause at all.” 
A common response by theologians is to argue that some interpretations of quantum physics do recover causality and frequently cite the Bohmian Pilot Wave theory  . But this theory has very little support from the scientific community as there is no evidence for pilot waves  . The fact that there is no consensus on the right way to interpret quantum theory implies that at least it is not clear that causality is a fundamental property of the world. But let us suppose that it is. What then caused God? Theists must agree that there is something that doesn’t need a cause. And whilst acausal interpretations of quantum mechanics are still on the table it seems they have the advantage over God because at least we know that quantum mechanics actually exist. The theistic response is that only things that begin to exist need causes. As God didn’t begin to exist then he doesn’t need a cause. An obvious question to ask is how do theists know this? It seems to me like a pure assertion. But what if the universe didn’t begin to exist? Then it wouldn’t need a cause and we will not require God.
Here Justin and many other theists think they are on safer ground. The arrow of evidence, they claim, is clearly moving towards God as big bang cosmology points to a universe with a beginning. But in fact this is a mistake; my second appearance on the show was to discuss why. Amazingly my Christian “opponent” seemed to agree with most of my arguments that the big bang should not necessarily be associated with an absolute beginning of time. 
Despite this, Justin still repeats the Kalam argument, giving us a short history of cosmology which I think is rather misleading. There’s an often used theistic debating tactic which tells us it was atheists who all believed in a static universe. The history of modern cosmology is painted as a morality play where the stubborn atheist kicks and screams before being forced to accept the big bang. But the truth is many scientists, whether they were atheist or theist, believed in a static universe because that is what the evidence suggested. Furthermore at the time the big bang was first suggested it seemed to imply the universe was only 1.8 billion years old.  You didn’t need to be motivated by atheism to reject that and in fact many theists backed the steady state.  Of course eventually the age of the universe got revised and the big bang became more robust.
Justin goes on to tell us that “physicists such as Stephen Hawking went on to develop theories which predicted the universe began its expansion from an ‘initial singularity’” . But that is not quite the real story. The universe is expanding and this can be expressed a number called the scale factor increasing over time. Think of the scale factor as like a map scale, indicating the distance between distant galaxies. If we wind the clock backwards the universe is contracting and the scale factor gets smaller.
One might imagine it could get smaller and smaller forever into the past. But singularity theorems imply that in a finite amount of time the scale factor becomes zero. There is effectively no distance between any two points. The density, pressure, curvature and temperature of the universe all become infinite and one can’t carry on the backward evolution of the universe beyond that. Hence the big bang is associated with a beginning of time at the singularity.
This was known as far back as the 1920’s. But the early version of the singularity theorems assumed that the universe was perfectly symmetrical, so there was little reason to take it seriously. What Penrose and Hawking did in the 1960’s was to show that you can relax that assumption and the singularity is still present. This was a major breakthrough but did it really show that Justin’s conclusion is correct?
Justin’s description of the universe at the singularity is” at the very earliest moment, it appears to have been something akin to “nothing at all”, giving the impression of match between science and Christian claims of creation ex-nihlo. But in Genesis God seems to move over the face of the water before he even does any creating. This led many Rabbis and some Christians to believe God created from pre existing materials rather than nothing.  And Genesis description of creation may not even be about the universe as we think of it, as the phrase Heaven and Earth is perhaps better translated as land and sky. 
When the steady state theory was popular, theologians appealed to passages that describe God’s continual sustaining of creation to make the bible compatible with that too.  So it seems that it is not so hard to find passages in the bible whose meaning can be molded to support whatever narrative suits.
One can imagine why Justin and other theologians describe the singularity as the universe shrinking down to no size at all as the scale factor is zero at the big bang. But the scale factor does not represent the size of the universe. The universe might have had infinite size even at the big bang. What the scale factor measures is the distance between points and therefore to associate the singularity with creation ex-nihlo is questionable.
Perhaps the model that most conforms to this concept of “creation ex-nihlo” is an ingenious, although speculative one developed by Alex Vilenkin.  In quantum physics particles can spontaneously fluctuate out of the vacuum. Vilenkin suggests that if we treat space-time quantum mechanically, then it too can fluctuate from “literally nothing”.
The notion was recently popularized by Lawrence Krauss. However many were quick to criticize him saying it’s a universe from a quantum vacuum, which isn’t nothing. Although the wrath they give to Krauss is rarely directed towards Vilenkin who is the one that originated the model and called it a universe from “literally nothing”. But Vilenkin's model is not a fluctuation from the vacuum but of the vacuum. It’s from a state with no space or time.
So if this model is right it seems the origin of the universe lies in the law of physics themselves. Perhaps they exist platonically and do have real causal powers. Maybe they are the uncased cause. The clear advantage of this line of reasoning over God is that we know the laws of physics exist and we know objects in the universe obey the laws of physics. We can’t say the same for immaterial minds. One might argue there are still laws of physics and these aren't nothing. But that leaves someone like Justin in a quandary. If science can describe the origin of the universe form nothing, why do we need God? If it can’t, what is the justification for equating creation ex-nihlo with modern science?
The theist can’t have it both ways.
One can question whether the singularity should be described as nothing. But why should we even believe singularities exist? Penrose and Hawking showed that the big bang must be associated with a singularity if a number of conditions are met. Firstly, gravity is always attractive. But both inflationary cosmology and dark energy imply a repulsive gravitational force so the first condition is not looking good. 
The second condition is that space-time has a description known as a Lorentzian manifold , in plain English, this means it has massive particles in it, with three space dimensions and one time dimension. Penrose now argues this is a mistake. The extreme temperatures in the early universe would prevent mass from forming. This changes the geometry, implying the singularity can be removed and Penrose appeared on Justin’s show to argue this leads to a cyclic cosmology.  Hawking now claims that quantum effects will change the geometry from a Lorentzian manifold to a Euclidean one. This means that the early universe is described by 4 space dimension and no time dimensions, again removing the boundary of the singularity.
Hawking is not shy in claiming this removes the need for God “But if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end: it would simply be. What place, then, for a creator?" 
Another condition is that there are no closed times like curves. In General Relativity space-time can curve, this is what explains gravity. But solutions to Einstein’s equation have been found that allow the time dimension to curve back on itself allowing time travel into the past. Some cosmologists have even said this can solve the mystery of our existence. In the early universe things were so highly curved that a lime loop forms and the universe could be its own mother.  This may sound farfetched but it’s based on genuine solutions to Einstein’s equations. Whether they are really realized in the universe or not, we don’t know.
The most important assumption of the Penrose Hawking theorems is that gravity is described by Einstein’s theory of general relativity. But Einstein’s theory breaks down when the observable universe was incredibly small as it does not include quantum effects. So we need a quantum theory of gravity to describe the earliest moments of the universe, the so called “Planck epoch”.
Our best attempts at quantum gravity such as string theory or loop quantum gravity seem to point to the same conclusion, the singularity is removed, and the big bang was not the beginning of time. One possibility is that that big bang becomes a big bounce from a prior contracting universe. In loop quantum cosmology there is a clear consensus that this is what happened.  Some models inspired from string theory such as string gas cosmology and the pre big bang  also have this feature as does another model inspired from Horava lifschitz gravity.  There are prospects for potentially testing these proposals. 
But there seems to be little prospect for observationally confirming the existence of a cosmological singularity and most theorists think it’s unlikely to exist in reality. Therefore today’s cosmologists no longer associate the big bang with the absolute beginning of time that is needed for the Kalam argument. When cosmologists say the universe is 13.8 billion years old they really mean this is how much time has elapsed since the expansion we see today began. They don’t necessarily mean nothing existed before the big bang.
Justin claims that infinites (especially an infinite past) are nonsensical, how could the universe every get to “now”? Hence the universe must have had a finite past. This assumes there was a beginning infinitely far away and the universe is somehow on a journey from this point. But past eternal models are not usually associated with such a point and so there is no such journey. It also assumes there is a unique sense of “now” that the universe has to get to. But relativity has no such moment.
To make the argument coherent one has to use a very non standard interpretation of relativity that has virtually no support from the scientific community. This non standard approach to relativity (known as the Neo Lorentzian interpretation) leads to what philosophers call an A theory of time, which has a definite “now”. The standard approach to relativity gives us something philosophers call the B theory of time. 
In a recent survey of philosophers the A theory was the least popular.  Of course this doesn’t prove the A theory is false. Perhaps physicists and philosophers have got it wrong but the important point to note is that the line of reasoning Justin uses with regards to past infinites requires that the A theory is true. Since we don’t know the A theory to be true we shouldn’t be persuaded by this line of reasoning.
It’s the fact that space-time becomes infinitely dense that allows one to connect the singularity with a beginning. But if infinites are impossible why believe in the singularity? And if you don’t believe singularities are real then on what basis should we connect modern cosmology with an absolute beginning? Ironically in many quantum approaches infinite density is impossible but that opens the door to a past eternal universe.
Justin then goes on to discuss the Borde Guth Vilenkin (BGV) theorem, which some have claimed proves a beginning independent of any of the assumptions we discussed above.
In our interview with Alan Guth (one of the theorems authors), he states it only shows that inflation (a period of ultra rapid expansion believed to have occurred in our past) had a beginning, not that the universe had a beginning.  If you believe inflation is preceded by a quantum fluctuation from nothing (as Vilenkin does) then this implies a beginning. But one can equally claim that prior to inflation was contraction and then there is no beginning. Guth favors the latter and Vilenkin the former. But the truth is no one knows what happened before inflation and so no beginning is proven.
Vilenkin did claim the BGV proves a beginning and Justin quote’s him to this effect. But he seems to have backed off this position, saying “Jaume Garriga and I are now exploring a picture of the multiverse where the BGV theorem may not apply”  . According to Guth and Vilenkin, inflationary cosmology inevitably leads to a multiverse.  So the beginning Vilenkin often talks about is not the beginning to our local big bang but a beginning to the multiverse. Here is how Vilenkin describes the big bang “It is no longer a one-time event in our past: multiple bangs went off before it in remote parts of the universe, and countless others will erupt elsewhere in the future.” 
Anthony Aguirre told us that these sorts of theorems can’t really show the universe has an absolute beginning. Instead what they can show is that the space-time that obeys the condition of the theorem has a past boundary. But that doesn’t prevent the existence of another space-time on the other side of the boundary that doesn’t obey the condition of the theorem. Aguirre claims that the BGV doesn’t even prove inflation cannot be past eternal.  Justin claimed that the theorem is “widely accepted”.
But other cosmologists have agreed with Aguirre including Leonard Susskind  and Yasunori Nomura,  both of whom argue for a past eternal multiverse although for different reasons. Even if they are wrong and the multiverse does have a beginning, it's not a beginning we are likely to ever confirm with observations. As Guth said: “I expect that any detailed consequences of such a theory would be completely washed out by the eternal evolution of the universe. Thus, there would be no way of relating the properties of the ultimate origin to anything that we might observe in today's universe.”  This represents a serious problem for theists claiming support for a beginning from science. They quote observations backing a big bang and they quote Vilenkin’s use of the BGV theorem. But it’s important to note the beginning Vilenkin is describing is not our local big bang. So those observations have questionable relevance.
The multiverse also clearly undermines Justin’s next step. He argues that the constants of nature are delicately fine tuned for life and this requires a God to do the tuning. He compares it with rolling a dice and continually getting a 6. Surely it’s more likely the dice was rigged than it happened by chance? We can conclude this because we can compare the two probabilities. We know that people can cheat at games of chance. But we don’t know that a conscious being can change a constant of nature. So the justification that one has for a dice game being rigged cannot be extended to the universe. To rule against chance, we need to know the frequency of attempts. The chances of throwing a fair coin and getting heads ten times in a row are 1,024 to 1. So we might ask, what are the odds of someone being able to rig the outcome? Are they more or less likely than 1,024 to 1? But what if we have actually made 1,024 attempts? We no longer need to appeal to someone rigging the coin. High frequency can overcome low probability. In a multiverse this frequency is potentially infinite. A multiverse is not the only way to get a high frequency. Some have suggested there is evidence the constants of nature vary within our universe and this could achieve the same effect.  Others have suggested a cyclic universe might have varying constants between the cycles.  Lee Smolin has suggested there might be a selection effect.  Perhaps black holes give rise to new universes and so the universe that makes the most black holes will have a selection pressure in favor of it. There would a sort of cosmic natural selection, but the cosmos would not be selecting for life but for black holes.. Fortunately for life, the two are associated with each other as life and black holes are fueled by dying stars. Life would just be a happy by product of black hole selection. But even if we knew nothing of any of these models (which we could bracket under the term ‘world ensemble”) we would have to say the frequency of events for the universe is simply unknown. And if the frequency of events is unknown then it is not reasonable to rule out chance.
Moreover a key difference between rolling a dice and getting a life permitting universe is a selection effect. Beings like us must find themselves in a universe that has constants that are compatible with their existence. Note that with the existence of many universes, this is nothing more than a statement of consistent logic---to explain what *we* observe, we need to calculate probabilities under the condition that we exist. In this sense, the example of having only 6's in throwing a dice is completely irrelevant---there is no reason that we exist only if the outcomes are all 6.
Imagine you have won the lottery but you know nothing of lotteries. The only thing you are told is the odds of winning are astronomical. What should you conclude? That a God picked out the winning lottery ticket for you? Interestingly many people that have won the lottery have claimed divine intervention which shows how prone we are to misinterpreting rare events  . Maybe you could speculate there are lots of lottery tickets sold. Even if this remained pure speculation it seems to be a very reasonable one. So even if we had no independent reason for thinking there was any kind of world ensemble we could be just as justified in believing in it on the basis of fine tuning as the theist believes in God.
I was very flattered to find the scientific case for a multiverse is one issue where Justin has changed his mind. On my third appearance on Justin’s show, I argued that there were independent reasons for believing in a multiverse coming from inflationary cosmology. Yet again I was surprised (as was Justin) to find my Christian “opponent” pretty much agreed with everything I said. In fact it seemed he was more convinced of the multiverse than I was!  Justin had to concede in his book that this was an “important lesson in humility…I had overstated the case against the multiverse... Nevertheless Phil’s intervention hadn’t persuaded me that fine tuning is a dead end” .
I’ll try and do that now.
Justin states that the multiverse can never be “physically confirmed”. But a number of empirical probes of the multiverse were discussed in our film on eternal inflation, something Justin saw in preparation for our show.
Cosmologists can probe the universe’s oldest light (the CMB) to see which models of inflation are favored. When we interviewed George Efstahtiou who gave the cosmology results for ESA’s Planck probe, he claimed Planck favored models of inflation that lead to a multiverse, which is not surprising, as according to Guth, virtually all models of inflation do this. 
There’s also the possibility of detecting a signature of bubble collisions within the CMB, if we were lucky enough to bump into another universe in our past.  So far nothing definitive has been found. But with future polarization data, it is still possible that such a signal could be found.  Justin himself mentioned the cold spot, an anomalous feature of the CMB that could be such a bubble collision. Recently a more mundane explanation for the cold spot has been ruled out, upping the probability that it’s from a bubble collision. 
Another possibility has been proposed by Vilenkin and Guth. Super massive black holes might be formed through universe bubble nucleation inside our pocket universe. By measuring the masses of black holes in the early universe it might be possible to test this scenario. 
Steven Weinberg used the multiverse to predict the existence of dark energy ten years before it was discovered.  So we do have some physical evidence for a multiverse. Is that enough? I don’t think so. We should be skeptical of such claims until we have more evidence. But if one takes the view that one should reject the multiverse due to a lack of direct empirical verification why not also reject fine tuning itself? After all, we can’t empirically check that changing this or that constant would prevent life. Roger Penrose has gone as far as to say “the main thing that I am not happy about is that I don't see how we have the remotest idea what would happen in a world where the constants of nature were different” 
Perhaps Sir Roger was using a bit of hyperbole. I think we can have ideas about what would happen, but the important point is no one knows any way to test this with observations. In science I think we shouldn’t ignore the work of theorists and simulations but unless they can be confirmed by experiment we should not treat them as fact. Maybe this would be tempting if no one could find any flaw in the theory. But that is not the case with fine tuning. As we shall see there are many papers claiming the constants of nature can be different without preventing life.
Bill Craig in his debate with Sean Carroll, broadcast on Justin’s show, gave a list of prominent physicists who think the fine tunings are real. Some of these physicists I have personally met and they told me they are not convinced by most case of fine tuning.  Alan Guth is one; Roger Penrose as described above, is another.  Both Penrose and Guth have written extensively on the two very examples of fine tuning that Justin uses in his book.
Justin states the low entropy of the universe is fine tuned, something inspired by the work of Penrose who said “this now tells how precise the Creator's aim must have been, namely to an accuracy of one part in 10 to the 10 to the 123rd power. This is an extraordinary figure.” 
When Penrose talks of a creator he’s using the phrase metaphorically, implying that the low entropy state could not have been selected at random. Secondly as pointed out by Sean Carroll in the same debate, the low entropy of the universe is not fine tuned for life. The entropy could have been enormously higher and life would still be fine. I asked Penrose if he agreed with Carroll on this and he enthusiastically replied yes, adding it’s not really a case of fine tuning at all! What Penrose suggests is that there must have been a pre big bang state that effectively forced the big bang into a low entropy state. This is something many of the cosmologists I have interviewed agreed with, although they have different mechanisms to achieve it. So rather than pointing to the conclusion Justin wants: God. The low entropy state, according to the very scientists that are often quoted by theists, may imply a conclusion they don’t want, a pre big bang universe.
The next example Justin gives is the force of gravity “gravity acts a universal superglue...Were the force of gravity ever so weaker than it is, the glue would become too weak, and no objects of any sort would be able to form…Science tells us that if differed from its value by one part in 10^60 then the universe as we know it would not be able to exist. “
There is an obvious problem with this statement. We don’t know what the strength of gravity actually is to that level of precision. Scientists have made dozens of attempts to measure it and most of them come up with quite different values.  But if G can’t vary by 60 decimal places, then all but one of these values should be ruled out. So my challenge to Justin is to tell us which one of the many estimates is the right one.
It is perhaps more meaningful to talk about fine tuning in terms of what are known as dimensionless constants. In other words the ratio of one constant to another. So, discussing about the strength of gravity is equivalent to discussion of variations of other (mass) scales in the theory.
What I think Justin really means is that a ratio called Omega is fine tuned to 60 decimal places. Omega measures how flat the geometry of the universe is. It was known to be close to 1 for our current universe, but this seemed like an unstable solution. Bob Dicke pointed out that Omega had to be 1 to an accuracy of 15 decimal places one second after the big bag, to allow for life. The discrepancy between 15 and 60 decimal places depends on how far you extrapolate back,  go all the way to the Planck epoch and the number is 59, one second after the big bang it’s 15.
As we don’t understand the physics of the Planck epoch it may not be appropriate to extrapolate as far as Justin does. But Dicke’s calculation depended on gravity always being attractive. Guth argues that the early universe underwent a period of rapid expansion called inflation. Inflation was described by a phase transition known as super cooling which leads to gravitational repulsion and so Dicke’s calculations are turned upside down. Omega can start anywhere at all and will be driven to one during inflation. Guth famously wrote in his notebook: ”spectacular realisation , this kind of super cooling can explain why the universe today is so incredibly flat and hence the resolve the fine tuning paradox pointed out by Dicke” . 
This is considered such an important breakthrough that this page of Guth’s notebook is now on display at the Adler planetarium.
Since Guth’s work other cosmologists have claimed alternative ways to solve the flatness problem, so even if inflation is wrong that doesn’t justify Justin’s answer of God.  These alternative solutions yet again imply a pre big bang universe. Most cosmologists probably accept inflation however as, unlike God, it seems to predict the right statistical properties of the CMB. The low entropy state and omega are not the only examples of potential scientific resolutions to fine tuning. Some papers have argued the cosmological constant does not need to be fine tuned,  others that weak force needs no fine tuning,  and others still that the strong force can vary without any problem for life  . Scientific American ran the following editorial comment as a result of some of these papers: “These finding suggest the universe may not be as finely tuned for life as previously thought”  .
Of course there are many cosmologists on Craig’s list who are genuinely persuaded of fine tuning and there may well be more papers claiming the reality of fine tuning than its opposite. But most of those names are also persuaded of some type of world ensemble too.  And I suspect there are more papers arguing for the reality of such a structure than not. So appeals to popularity amongst prestigious scientist are a double edged sword for the theist.
It’s worth looking at one last example of fine tuning that Justin raised in a blog post but didn’t discuss in his book. “For instance the cosmological constant (the dark energy density of the universe) is fine-tuned within 1 part in 10^120. If it had been wide of that tiny mark then the universe would either have expanded too rapidly for galaxies and stars to form or it would have collapsed in on itself before anything formed.”
Like the entropy of the early universe, Justin is conflating two different notions of fine tuning. One way to define fine tuning is to ask if a value for a constant is “natural”. In other words, dimensionless numbers in physics shouldn’t be too large or too small. Another is the one used by theists, implying a parameter can’t differ by much without being fatal for life. In the case of the cosmological constant (CC) one is able to use quantum theory to calculate its value and the number we get is spectacularly wrong. It comes out as 120 orders of magnitude too high. However these calculations are very difficult to do and scientists thought there must be some symmetry principle that cancels out the huge term they were getting and sets the CC to zero. But after 1998 and the discovery of dark energy, it would have to cancel out to almost zero, but not quite, and this is the sense in which the CC is fine tuned to 120 decimals places.  It seems like an “unnatural solution”. The dominant explanation of the CC problem is the multiverse. Some have argued that fine tuning is actually evidence for a multiverse. Another approach is to argue we are doing the calculations wrong. Some have suggested we need to modify our basic equations and then the CC problem goes away  . George Ellis is a Christian cosmologist who favors this approach. His criticism of the multiverse is often quoted by theists, but they usually fail to mention this. 
Not all physicists agree these are problems for example Sabine Hossenfleder questions how we can determine the probability of a constant
It’s true if the CC was much larger life would be in trouble. But not by 120 decimal places. In fact some estimates have said it could be as much as two orders of magnitude higher than its current value without threatening the existence of life.  It could also be much smaller without threatening life. Ten times smaller is no problem; a trillion times smaller is no problem. Don’t believe me? Just look up what cosmologists thought the cosmological constant was before 1998. They thought it was zero; nobody thought the world did not exist as a result. A zero cosmological constant represents no problem for life. Don Page, an evangelical Christian and well respected cosmologist, (who was on Bill Craig’s list as supporting fine tuning) claimed the cosmological constant might even be evidence against fine tuning  . This is because a small negative value would be more conducive to life and hence if God was choosing the CC for life we would expect him to choose a small negative value, but what we observe is a small positive value.
Justin also rejects the multiverse because of Boltzmann brain’s (BB’s). This is the ideas that in a multiverse there will be random fluctuations that give rise to conscious brains in empty space. Given the large number of sterile universes, BB’s will outnumber Normal Observers (NO’s) and so the fact that we are not BB’S disfavors a multiverse.
But according to Guth the multiverse can fix the problems of a BB that exists even in a single universe. In a single universe that expands forever, NO’s will only exist near the beginning. BB’s will exist forever into the future and so outnumber NO’s. In a multiverse both are infinite. In infinite sets it’s still possible to do probability but one needs a counting procedure, what mathematicians call “a measure”. So whether or not BB’s outnumber NO’s depends on the measure. As scientists have found measures where NO outnumber BB’s it seems this is not a very convincing argument. 
I also find it ironic that many theists are convinced of the problem of BB’s even though no one has ever observed one. Some papers have claimed that BB’s cannot even form and so this is a non-problem  . Others argue that it might be possible to observe a BB, but it would not be possible to be a BB  . Yet some of those same theists that are convinced of BB’s seem unconvinced of evolution, something supported by overwhelming evidence.
Justin claims that inflation itself needs fine tuning. There are certainly papers in cosmology that argue this, but others that argue against it.  Justin gives no reason to believe the former rather than the latter. Because inflation is eternal it creates an infinite factor for the space-time volume and so as long the probability of inflation starting is not zero it will eventually dominate the space of probabilities. Hence Guth says that any low probability for inflation “is simply irrelevant”. Again this material was all discussed in our film that Justin saw. So it’s disappointing that he doesn’t engage with this argument but merely repeats the theist line, that inflation needs fine tuning and Boltzmann brains disproves a multiverse.
Justin is convinced that fine tuning is a huge problem and gives us three possible explanations: necessity, chance or design.
He rules out chance because of the high probabilities involved. But in a multiverse or some other type of world ensemble, this is clearly misguided. If there are many universes having different properties, then there are some universes in which the conditions to support life are met (although they are a small fraction). Life would emerge *only* in these rare universes, as observers like us.
He rules out necessity because there is no obvious reason why the constants of nature take on the values they do. But several cosmologists we have interviewed have suggested the constants may well be necessary. It’s true that in string theory the constants seem to be able to take an enormous number of possible values. So if string theory is right and we have understood it correctly then necessity seems to be ruled out. This is an argument Bill Craig used in his debate with Sean Carroll  . But the problem is we don’t know if string theory is true. We don’t even know if we have understood it properly. And therefore we cannot rule out necessity so quickly.
What about design? Well the problem here is that Justin isn’t just asking us to believe in a designer, but an immaterial one. Whenever we see design by agents we see they are physical, they need external energy to do their design work. We also see that complex creatures capable of design arise after long periods of evolution. We also see that the more complicated a designed object is, the more the number of designers are needed.
Think of the Large Hadron Collider, one of the most complex objects on Earth. It wasn’t designed by one person. So if cosmic design is like Earthly design, shouldn’t we presume there are many designers? Design by a single immaterial being that didn’t undergo evolution and doesn’t need any external energy source, doesn’t seem to fit what we know about design at all. Theists merely appeal to the similarities that suit and ignore the ones that don’t. As an atheist then it seems this type of design is the least plausible of Justin three explanations.
If however you already believe in God then perhaps you might be tempted, to think of God as the best explanation. But recently some prominent theist philosophers have argued this is a temptation that should be resisted. That the fine tuning argument is not a good reason to believe in God and may not even be compatible with the Christian theism they profess.
One such philosopher is Hans Halvorson, a Professor of Philosophy of Physics at Princeton University. Halvorson argues that if God loves life and sets the odds for life then we should expect the odds for life to be high  . But what is the fine tuning really telling us? It implies the odds for life are low, so fine tuning should be just as much of a mystery to the theist as to the atheist.
Let’s return to Justin’s dice example. If God wants the dice to land 6 every time, he could make every side a 6. Therefore the fact that every side is not a 6 is not consistent with the belief that God wants 6 every time. The actual analogy Halvorson uses is to think of a giant urn filled up with a large number of purple balls and one yellow ball. A ball is picked out and it’s yellow. What could explain this unlikely event? The problem with appealing to a yellow ball loving God is that it is hard to explain why the urn is filled up with mostly purple balls in the first place.
In Christian theism God is the author of all reality and so he must have filled up the urn. This is why I personally think fine tuning might be an argument that could be used for deism, but not for theism. Perhaps theists think that deism is just sort of halfway to theism. Arguments for deism aim to show there is some sort of God, and then one can use the resurrection to prove it’s the Christian God.
But in some ways the deist God is inconsistent with the theist God. In deism the belief is that there is an intelligent creator of the universe but this creator does not intervene in the universe after it’s created and is not necessarily perfect and may not even have any of the Omni properties of the theist God (all powerful, all knowing etc.). This is important because fine tuning seems to imply there is some constraint on the designer’s choices. He has to rig the game because the game is not set up for the outcome he wants. If the game was set up for the preferred outcome, no rigging would be needed. That is why fine tuning might support deism but it doesn’t support Christian theism.
But if fine tuning is an argument against Christian theism why is Halvorson still a Christian? The answer may that he challenges the notion that probability for life is small. One can imagine that constants of nature can take on literally any value so there is no way to really calculate the probability of the observed values. “If you claim that something is probable or not probable, you should only say it if you have a measure, that’s if you have a rigorous mathematical way of counting the possibilities... in no rigorous physics that I know of are there probability measures given over parameter spaces”  .
Tim and Lydia Mcgrew, two prominent Christian’s philosophers who have both appeared on Justin’s show, make a similar argument  . Notably they have never been asked to make that argument on Justin's show.
Even Michael Demsbki, the darling of the intelligent design movement has expressed serious reservation about fine tuning.
Hud Hudson is a theologian keen to use a defense against the problem of evil known as skeptical theism. This argues that in the face of apparent gratuitous evils we cannot know the potential value of outweighing goods. Consider that God could have created beings that don’t occupy physical bodies and so there’s really no need for him to fine tune the universe at all. The fine tuning proponent must assume that it’s a good thing for God to create embodied conscious agents with regular laws, but then that assumes knowledge of what God would find good. Why then shouldn’t we also assume that God would have stopped the holocaust? Since God didn’t stop the holocaust then the theist must appeal to what Hudson calls “epistemic humility” i.e. we don’t know what God would find good, an assumption needed to advance fine tuning. As Hudson wants to keep skeptical theism he argues we must reject fine tuning  .
These are powerful arguments yet Justin does not engage with them. One argument Justin does engage with is that the constants of nature must be suitable for life otherwise we wouldn’t be here to observe them. So the present value of the constants of nature should not be surprising. The response given by Justin is John Leslie’s analogy of a firing squad. Suppose you are about to be executed by a firing squad and all of the marksmen miss, after your miraculous survival you say there’s nothing to explain, if they hadn’t missed I wouldn’t be here to ask why. Isn’t it more reasonable to think there is some explanation as to why they all missed? It seems likely intelligent intervention is the best response. Perhaps the marksmen were bribed by someone that wanted you to live. But in the firing squad case, you have a reasonable expectation based upon experience of what you should expect under normal circumstances. Every time the firing squad has shot in the past they’ve hit their mark.
But we can’t do this for the universe. How many times have we seen universes come into being? Only once and therefore we can’t have the same confidence for what the universe should look like under normal circumstances as we do for the firing squad. We also have experience of people taking bribes; we know this happens with non trivial frequency.
But again we don’t know that immaterial minds exist and we don’t know that a mind can change the constants of nature at will. In the firing squad case we do not need to appeal to intelligent intervention. Perhaps there was an unusual gust of wind. Maybe the entire platoon was using the same type of gun that had a flaw only present in some unusual temperature that was present that day. These may be chance events but they may be more likely to happen than simply assuming the marksmen all happened to miss by coincidence. The firing squad analogy is just not a good one for the universe.
Another objection Justin covers is the waste argument. The majority of the universe is mostly empty space; it’s actually hostile to life. The vast majority of the history of the universe also seems to be hostile to life. But according to Justin this vast waste of space and time is actually needed. We need time for stars to burn their fuels to make the materials for us and the universe is expanding, so that explains why it’s so big. It’s not really a waste at all. But again the problem is that whilst under naturalism we may need time for stars to burn their fuel, this isn’t true under theism. God could just make the elements ex-nihlo. So again the theist is trying to have their cake and eat it.
For many theists, God creates life via super natural act. But why is this necessary if the universe is delicately fine tuned for life? Just as it doesn’t make sense to assume Harry Potter would spend time fine tuning the aerodynamics of his broom stick for flight, it shouldn’t make sense to think God would need to fine tune the constants of nature.
We cansummarise the fine tuning argument as asserting that the probability of life under theism is high and low under atheism. But this line of argument is extremely dubious. We don’t really know the probability of either. Why should we expect the probability of life to be high under theism? If God wants fellowship with other conscious beings he can create disembodied conscious agents ( isn’t that what populates heaven?) so there seems to be no a priori reason to think the probabilities of life under theism are actually high. It’s a probability derived from one observation and after the facts are already known and that should make us deeply suspicious. It’s also no part of atheism to say that constants of nature must be randomly chosen. This may or may not be true given atheism. And our confidence in determining probability is further undermined by a point made by Sean Carroll and Alan Guth  . Imagine we were given the value of all the constants and the laws and were asked to predict if our universe has life in it. Could we do it? It seems the answer is no, we would for example, mistakenly presume that the matter and anti matter would annihilate each other and create a sterile universe. We would get a false negative for the one case we can actually observe. So should we really have such high confidence in all the negatives that we can’t observe?
As a mathematician once told me, if you find an extremely unlikely outcome the first time you do an experiment, the best explanation may be that you were wrong that the outcome was extremely unlikely.
Let’s imagine the probability for life was actually high. It’s not hard to imagine a reverse fine tuning argument in this case. God so loves life he made it so that every possible value for the constants supports life. Surely the theist would claim that too would be a miracle that proves his existence. In an atheistic universe the laws must be such that they allow for life as long as life and laws exists. But under theism these are an optional extra. God does not need life permitting constants. So fine tuning is not a prediction of theism.
Justin himself formulates the argument as a best explanation. But good explanations have uncontroversial assumptions, assumptions that don’t conflict with what we know, assumptions that are not grandiose and lead to testable predictions. The assumption of an immaterial mind that can do anything does not meet these criteria and so should be rejected as a best explanation.
Even it was the best explanation that should not mean it’s a convincing one. Imagine you are a detective in a murder, you have two suspects. One has three alibis and the other four. The best explanation is clearly the one with three alibis. But is it good enough? Would you really convict someone of a crime if they had three alibis? Perhaps in this case the best thing to do is to recognize that even your best explanation just isn’t good enough and one should simply admit that the mystery is unsolved.
This also applies to Justin’s last argument in this chapter, for the applicability of mathematics to the universe. He quotes the physicist Eugene Wegner who talks of the unreasonable effectiveness of mathematics. Justin again appeals to God as the best explanation. But why is it unreasonable to assume mathematics should describe the universe if it’s governed not by a mind but by natural laws? If God frequently performs miracles, can we really say there is so much regularity in the world? We are being asked to believe that God sets up immutable mathematical relationships in the world only to suspend them every time he does a miracle.
Of course you can imagine that God is a great mathematician and so used mathematics for his master design. We can use elegant mathematics to describe the evolution of the universe because God is an elegant designer. If we move away from cosmology to geology though we find the elegant mathematics is gone. There is no known way to predict Earthquakes with some simple formula. In fact at the moment we cannot predict Earthquakes at all. Predicting the weather more than a few days out seems to be practically impossible as the system is so chaotic.
If God loves elegant mathematical formulas why do they not apply here? Let’s not forget that Einstein resisted quantum theory because he refused to believe that universe should have such inbuilt randomness. We can use quantum theory to very precisely predict when half of a radioactive substance will decay but we can’t predict which half. Why should this be so under theism? Again have no doubt the theist will say that too was all parts of Gods intention.
Theism makes no predictions for the world we see but there is no limit to the phenomenon that it can claim credit for using post hoc explanations. This is the real problem with the God hypothesis; because God is assumed to be able to do anything, and his intentions are mysterious, he can be made to fit anything we observe. The input assumption and the output explanation are essentially the same thing and that is not a feature of a satisfactory resolution to the mysteries or our existence. So Justin’s claim that God is provides a convincing explanation for our existence should be rejected.
 The Big Picture by Sean Carroll , One World Publications 2016
 Many Worlds in One by Alex Vilenkin, Hill and Wang 2007
 For example REASONABLE FAITH: CHRISTIAN TRUTH AND APOLOGETICS (CROSSWAY: 2008), PP.114- Criag claims “A great many physicists today are quite dissatisfied with this view (the so-called Copenhagen Interpretation) of quantum physics and are exploring deterministic theories like that of David Bohm.”
 A recent survey here got o% support for Bohm’s ideas A Snapshot of Foundational Attitudes Toward Quantum Mechanics by Maximilian Schlosshauer , Johannes Kofler and Anton Zeilinger Stud. Hist. Phil. Mod. Phys. 44, 222-230 (2013)
 You can listen to the show here: https://www.youtube.com/watch?v=rPHoCDAlX9w&t=968s&list=PLJ4zAUPI-qqrWYUk2T9WUTwXEDpz2Y324&index=1
 Hubble, E. (15 March 1929). "A relation between distance and radial velocity among extra-galactic nebulae" . Proceedings of the National Academy of Sciences. 15 (3): 168–173.
 Theism and Physical Cosmology, Halvorson, Hans and Kragh, Helge (2010) http://philsci-archive.pitt.edu/8441/
 The History of Creation Ex-nihilo Within Jewish Thought by Rabbi Rafael Salber http://www.hashkafacircle.com/journal/R2_RS_exni.pdf
 For a good discussion see The Genesis Account: Six Hebrew Words Make All the Difference by Brian Bull and Fritz Guy http://spectrummagazine.org/article/brian-bull/2012/11/11/genesis-account-six-hebrew-words-make-all-difference
 Theism and Physical Cosmology, Halvorson, Hans and Kragh, Helge (2010) http://philsci-archive.pitt.edu/8441/
Volume 117, Issues 1–2 react-text: 70 , /react-text react-text: 71 4 November 1982 /react-text react-text: 72 , Pages 25-28
BEFORE THE BIG BANG:
AN OUTRAGEOUS NEW PERSPECTIVE AND ITS IMPLICATIONS FOR PARTICLE PHYSICS by Roger Penrose Proceedings of EPAC 2006, Edinburgh, Scotland
 A Brief History of Time by Stephen Hawking Random House 1988
 Can the Universe Create Itself? By Richard Gott and Li-Xin Li Phys.Rev. D58 (1998) 023501
 Singularity Resolution in Loop Quantum Cosmology: A Brief Overview by Abhay Ashtekar J.Phys.Conf.Ser.189:012003,2009
 String-inspired cosmology by David Wands Classical and Quantum Gravity Published 12 June 2002
Loop quantum cosmology:
From pre-inflationary dynamics to observations by Abhay Ashtekar and Aurélien Barrau Classical and Quantum Gravity Published 2 November 2015
 Balashov, Y. and Janssen M. (2002), Presentism and Relativity, http:/philsci-archive.pitt.edu, in British Journal for the Philosophy of Science.
 PhilPapers Surveys https://philpapers.org/surveys/results.pl
 Before the Big Bang 4 : Eternal inflation and the Multiverse https://www.youtube.com/watch?v=QqjsZEZMR7I
 This was an email sent to Lawrence Krauss . Bill Criag reproduced the entire email and a lot fo fans of Craig made a big deal about Vilenkin saying Criag had represented him fairly. But what they missed is the fact the Vilenkin no longer considers the BGV a proof of the beginning , read the email here: http://www.reasonablefaith.org/honesty-transparency-full-disclosure-and-bgv-theorem
 Eternal inflation and its implications by Alan Guth J.Phys.A40:6811-6826,2007
 Many Worlds in One by Alex Vilenkin, Hill and Wang 2007
 Eternal Inflation, past and future by Anthony Aguirre https://arxiv.org/abs/0712.0571
 Was There A Beginning? By Leonard Susskind https://arxiv.org/abs/1204.5385
 Static quantum multiverse Yasunori Nomura Phys. Rev. D 86, 083505 – Published 2 October 2012
 From an interview with Guth here: http://www.counterbalance.org/cq-guth/etern1-frame.html
 Quantum Cosmology and Varying Physical Constants by Katarzyna Leszczyńska Universe 2017, 3(2), 46 Conference Report
 An example can be found in this story http://nypost.com/2016/05/13/family-used-divine-intervention-to-win- 430m-powerball-jackpot/
 You can listen to the whole show here: https://www.youtube.com/watch?v=Jb3lfAmVK6M
 Both claims are made in our film Before the Big Bang 4 Eternal Inflation and the Multiverse https://www.youtube.com/watch?v=QqjsZEZMR7I&t=1969s
 Towards observable signatures of other bubble universes by Anthony Aguirre, Matt Johnson and Assaf Shomer 10.1103/PhysRevD.76.063509
 Evidence against a supervoid causing the CMB Cold Spot by Ruari Mackenzie et al https://arxiv.org/abs/1704.03814
 Black holes and the multiverse by Jaume Garriga , Alexander Vilenkin , Jun Zhang Journal of Cosmology and Astroparticle Physics Volume 2016 , Issue Number Tile Start February 2016 also see our video Before the Big Bang 4 Eternal Inflation and the Multiverse
 Weinberg, S (1987). "Anthropic Bound on the Cosmological Constant". Phys. Rev. Lett. 59 (22): 2607–2610.
 See the interview with Perose in the Time of India http://timesofindia.indiatimes.com/interviews/Roger-Penrose-Impossibilities-in-the-real-world-have-to-be-possible/articleshow/7290171.cms
 A transcript of the debate is hhere: http://www.reasonablefaith.org/god-and-cosmology-the-existence-of-god-in-light-of-contemporary-cosmology
 Guth gives his doubts on Fine tuning here http://www.counterbalance.org/cqinterv/cq2-4-body.html?b=cqinterv/ag-body.html . for Penrose see reference 40 and our upcoming film on our channel : skydivephil.
 Roger Penrose, The Emperor's New Mind, 1989; Michael Denton, Nature's Destiny, The New York: The Free Press
 Gravity on the balance Terry Quinn Nature Physics 12, 196 (2016) doi:10.1038/nphys3651 Published online 02 February 2016
 Eternal Inflation and its Implications, Alan Guth , Journal of physics Volume 40 , number 25
 The Inflationary Universe by Alan Guth, Vintage; New Ed edition (2 July 1998)
 For example, VSl models, ekpyrotic , CCC, matter bounce. Many of these are and will be discussed in film on our channel: skydivephil
 Is dark energy really a mystery?
Eugenio Bianchi, Carlo Rovelli & Rocky Kolb
Nature 466, 321–322 (15 July 2010)
 Big Bang Nucleosynthesis: The Strong Nuclear Force meets the Weak Anthropic Principle
 SCIENTIFIC AMERICAN JANUARY 2010
 The list can be seen http://www.reasonablefaith.org/god-and-cosmology-the-existence-of-god-in-light-of-contemporary-cosmology#section_4 . there are twenty five names on it and virtually every single one of them has expressed support for some form of world ensemble; either a multiverse as in the case of Guth, Linde, Rees, Hawking etc or a cyclic universe as in the case of Penrose or Ellis or Cosmic Natural Selection in the case of Smolin.
 Is dark energy really a mystery? Eugenio Bianchi, Carlo Rovelli & Rocky Kolb Nature 466, 321–322 (15 July 2010)
 One of many examples can be found here: “How the huge energy of quantum vacuum gravitates to drive the slow accelerating expansion of the Universe” by Qingdi Wang, Zhen Zhu, and William G. Unruh Phys. Rev. D 95, 103504 (2017)
 Scientific alternatives to the anthropic principle by Lee Smolin in Universe or Multiverse ? by Bernard Carr Cambridge University Press; 1 edition (6 Aug. 2009)
 Preliminary Inconclusive Hint of Evidence Against Optimal Fine Tuning of the Cosmological Constant for Maximizing the Fraction of Baryons Becoming Life by Don Page https://arxiv.org/pdf/1101.2444.pdf
 See discussion in our video Before the Big Bang Eternal Inflation and the Multiverse.
 One of several example is here. What’s interesting in this case is that it assume the Bohmian interpretation of quantum mechanics that theologians like Bill Criag rely upon the to refute the notion that quantum mechanics provides an exception to the causal principle. The Bohmian Approach to the Problems of Cosmological Quantum Fluctuations
 Boltzmann Brains--I'd Rather See Than Be One by J Richard Gott III https://arxiv.org/abs/0802.0233
 See transcript of debate here: http://www.reasonablefaith.org/god-and-cosmology-the-existence-of-god-in-light-of-contemporary-cosmology
 God Doesn’t Need Fine Tuning by Hans Halvorson philsci-archive.pitt.edu/10924/1/fine-tuning-anon.pdf
 Does the Universe Need God by Hand Halovrson, talk given at the Ian Ramsey Centre for Science and Religion https://www.youtube.com/watch?v=SDwpTcSEjak
 Probabilities and the Fine-Tuning Argument: A Sceptical View
Timothy McGrew, Lydia McGrew and Eric Vestrup Mind Vol. 110, No. 440 (Oct., 2001), pp. 1027-1037
 William Dembski Interview on Closer to the Truth https://www.closertotruth.com/series/does-fine-tuned-universe-lead-god#video-2112
 Swinburnes Aestheitc Appeal by Hud Hudson in Reason and Faith Themes from Richard Swinburne edited by Michael Bergmann, Jeffrey E. Brower, Oxford University Press 2016
 Why Almost All Cosmologists are Atheists by Sean Carroll Faith and Philosophy 22, 622. Alan Guth view can be seen here http://www.counterbalance.org/cqinterv/cq2-4-body.html?b=cqinterv/ag-body.html