Wintery Knight

…integrating Christian faith and knowledge in the public square

MIT physicist explains the challenge of cosmic fine-tuning for naturalism

Here’s the article from Harper’s magazine.

The MIT physicist says that the fine-tuning is real, and is best explained by positing the existence of an infinite number of universes that are not fine-tuned – the so-called multiverse.

Excerpt:

While challenging the Platonic dream of theoretical physicists, 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. 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. Although we are far from certain about what conditions are necessary for life, most biologists believe that water is necessary. 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. The recognition of this fine-­tuning led British physicist Brandon Carter to articulate what he called the anthropic principle, which states that the universe must have the parameters it does because we are here to observe it. Actually, the word anthropic, from the Greek for “man,” is a misnomer: if these fundamental parameters were much different from what they are, it is not only human beings who would not exist. No life of any kind would exist.

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 is one answer. Indeed, a fair number of theologians, philosophers, and even some scientists have used fine-tuning and the anthropic principle as evidence of the existence of God. For example, at the 2011 Christian Scholars’ Conference at Pepperdine University, Francis Collins, a leading geneticist and director of the National Institutes of Health, said, “To get our universe, with all of its potential for complexities or any kind of potential for any kind of life-form, everything has to be precisely defined on this knife edge of improbability…. [Y]ou have to see the hands of a creator who set the parameters to be just so because the creator was interested in something a little more complicated than random particles.”

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. Some of those universes will be dead, lifeless hulks of matter and energy, and others will permit the emergence of cells, plants and animals, minds. 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.

I thought I was going to have to go outside this article to refute the multiverse, but Lightman is honest enough to refute it himself:

The… conjecture that there are many other worlds… [T]here is no way they can prove this conjecture. That same uncertainty disturbs many physicists who are adjusting to the idea of the multiverse. Not only must we accept that basic properties of our universe are accidental and uncalculable. In addition, we must believe in the existence of many other universes. But we have no conceivable way of observing these other universes and cannot prove their existence. Thus, to explain what we see in the world and in our mental deductions, we must believe in what we cannot prove.

Sound familiar? Theologians are accustomed to taking some beliefs on faith. Scientists are not. All we can do is hope that the same theories that predict the multiverse also produce many other predictions that we can test here in our own universe. But the other universes themselves will almost certainly remain a conjecture.

The multiverse is not pure nonsense, it is theoretically possible. The problem is that the multiverse generator itself would require fine-tuning, so the multiverse doesn’t get rid of the problem. And, as Lightman indicates, we have no independent experimental evidence for the existence of the multiverse in any case. Atheists just have to take it on faith, and hope that their speculations will be proved right. Meanwhile, the fine-tuning is just as easily explained by postulating God, and we have independent evidence for God’s existence, like the the origin of biological information, the sudden appearance of animal body plans, the argument from consciousness, and so on. Even if the naturalists could explain the fine-tuning, they would still have a lot of explaining to do. Theism (intelligent causation) is the simplest explanation for all of the things we learn from the progress of science.

We need to be frank about atheists and their objections to the progress of science. Within the last 100 years, we have discovered that the physical universe came into being out of nothing 15 billion years ago, and we have discovered that this one universe is fine-tuned for intelligent life. I don’t think it’s like that the last 100 years of scientific progress on the origins question are going to be overturned so that science once again affirms what atheists believe about the universe. Things are going the wrong way for atheists – at least with respect to science.

See it in action

To see these arguments examined in a debate with a famous atheist, simply watch the debate between William Lane Craig and Christopher Hitchens, and judge which debater is willing to form his beliefs on scientific progress, and which debater is forming his beliefs against the science we have today, and hoping that the good science we have today based on experiments will be overturned by speculative theories at some point in the future. When you watch that debate, it becomes very clear that Christian theists are interested in conforming their beliefs to science, and atheists are very interested in speculating against what science has shown in order to maintain their current pre-scientific view. That’s not what rational people ought to do when confronted with evidence.

Positive arguments for Christian theism

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Four ways that the progress of experimental science conflicts with atheism

When people ask me whether the progress of science is more compatible with theism or atheism, I offer the following four basic pieces of scientific evidence that are more compatible with theism than atheism.

Here are the four pieces of evidence best explained by a Creator/Designer:

  1. the kalam argument from the origin of the universe
  2. the cosmic fine-tuning (habitability) argument
  3. the biological information in the first replicator (origin of life)
  4. the sudden origin of all of the different body plans in the fossil record (Cambrian explosion)

And I point to specific examples of recent discoveries that confirm those four arguments. Here are just a few of them:

  1. An explanation of 3 of the 6 experimental evidences for the Big Bang cosmology (From an article from Caltech)
  2. Examples of cosmic fine-tuning to allow the existence of conscious, embodied life (From the New Scientist)
  3. Evidence that functional protein sequences are beyond the reach of chance, (from Doug Axe’s JMB article)
  4. Evidence showing that Ediacaran fauna are not precursors to the Cambrian fossils, (from the journal Nature)

Atheists will typically reply to the recent scientific discoveries that overturned their speculations like this:

  1. Maybe the Big Bang cosmology will be overturned by the Big Crunch/Bounce so that the universe is eternal and has no cause
  2. Maybe there is a multiverse: an infinite number of unobservable, untestable universes which makes our finely-tuned one more probable
  3. Maybe the origin of life could be the result of chance and natural processes
  4. Maybe we will find a seamless chain of fossils that explain how the Cambrian explosion occurred slowly, over a long period time

Ever heard any of these responses?

Below I list some resources to help you to respond to the four responses of atheists to the experimental data.

1) The Big Crunch/Bounce has been disproved theoretically and experimentally.

Theoretically:

Nature 302, 505 – 506 (07 April 1983); doi:10.1038/302505a0

The impossibility of a bouncing universe

ALAN H. GUTH* & MARC SHER†

*Center for Theoretical Physics, Laboratory for Nuclear Science and Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA

†Department of Physics, University of California, Irvine, California 92717, USA

Petrosian1 has recently discussed the possibility that the restoration of symmetry at grand unification in a closed contracting Robertson–Walker universe could slow down and halt the contraction, causing the universe to bounce. He then went on to discuss the possibility that our universe has undergone a series of such bounces. We disagree with this analysis. One of us (M.S.) has already shown2 that if a contracting universe is dominated by radiation, then a bounce is impossible. We will show here two further results: (1) entropy considerations imply that the quantity S (defined in ref. 1 and below), which must decrease by ~1075 to allow the present Universe to bounce, can in fact decrease by no more than a factor of ~2; (2) if the true vacuum state has zero energy density, then a universe which is contracting in its low temperature phase can never complete a phase transition soon enough to cause a bounce.

Experimentally:

The universe is not only expanding, but that expansion appears to be speeding up. And as if that discovery alone weren’t strange enough, it implies that most of the energy in the cosmos is contained in empty space — a concept that Albert Einstein considered but discarded as his “biggest blunder.” The new findings have been recognized as 1998’s top scientific breakthrough by Science magazine.

[...]The flood of findings about the universe’s expansion rate is the result of about 10 years of study, said Saul Perlmutter, team leader of the Supernova Cosmology Project at Lawrence Berkeley National Laboratory.

Perlmutter and others found such a yardstick in a particular kind of exploding star known as a Type 1A supernova. Over the course of several years, the astronomers developed a model to predict how bright such a supernova would appear at any given distance. Astronomers recorded dozens of Type 1A supernovae and anxiously matched them up with redshifts to find out how much the universe’s expansion was slowing down.

To their surprise, the redshift readings indicated that the expansion rate for distant supernovae was lower than the expansion rate for closer supernovae, Perlmutter said. On the largest scale imaginable, the universe’s galaxies appear to be flying away from each other faster and faster as time goes on.

“What we have found is that there is a ‘dark force’ that permeates the universe and that has overcome the force of gravity,” said Nicholas Suntzeff of the Cerro Tololo Inter-American Observatory, who is the co-founder of another group called the High-z Supernova Search Team. “This result is so strange and unexpected that it perhaps is only believable because two independent international groups have found the same effect in their data.”

There has only been one creation of the universe, and the universe will never reverse its expansion, so that it could oscillate eternally. That view is popular, perhaps in part because many people watched videos of Carl Sagan speculating about it in public school classrooms, but all it was was idle naturalistic speculation, (Sagan was a naturalist, and held out hope that science would vindicate naturalism), and has been contradicted by good experimental science. You should be familiar with the 3 evidences for the Big Bang (redshift, light element abundances (helium/hydrogen) and the cosmic microwave background radiation. There are others, (radioactive element abundances, second law of thermodynamics, stellar lifecycle), but those are the big three. Point out how the experimental evidence for the Big Bang has piled up, making the problem even worse for the eternal-universe naturalists.

2) The multiverse has not been tested experimentally, it’s pure speculation.

Speculation:

Multiverse thinking or the belief in the existence of parallel universes is more philosophy or science fiction than science. ”Cosmology must seem odd to scientists in other fields”.

George Ellis, a well-known mathematician and cosmologist, who for instance has written a book with Stephen Hawking, is sceptical of the idea that our universe is just another universe among many others.

A few weeks ago, Ellis, professor emeritus of applied mathematics at the University of Cape Town, reviewed Brian Greene’s book The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos (Knopf/Allen Lane, 2011) in the journal Nature. He is not at all convinced that the multiverse hypothesis is credible: ”Greene is not presenting aspects of a known reality; he is telling of unproven theoretical possibilities.”

According to professor Ellis, there is no evidence of multiverses, they cannot be tested and they are not science.

Ellis is not the only multiverse sceptic in this universe. A few months ago, science writer John Horgan wrote a column in Scientific American, expressing his doubt in multiverses.

When you get into a debate, you must never ever let the other side get away with asserting something they have no evidence for. Call them on it – point out that they have no evidence, and then hammer them with evidence for your point. Pile up cases of fine-tuning on top of each other and continuously point out that they have no experimental evidence for their speculations. Point out that more evidence we get, the more cases of fine-tuning we find, and the tougher the problem gets for naturalists. There is no evidence for a multiverse, but there is evidence for fine-tuning. TONS OF IT.

3) Naturalistic theories for the origin of life have two problems: can’t make the amino acids in an oxydized atmosphere and can’t make protein and DNA sequences by chance in the time available.

Building blocks:

The oxidation state of Hadean magmas and implications for early Earth’s atmosphere

Dustin Trail, E. Bruce Watson & Nicholas D. Tailby

Nature 480, 79–82 (01 December 2011) doi:10.1038/nature10655

[...]These results suggest that outgassing of Earth’s interior later than ~200?Myr into the history of Solar System formation would not have resulted in a reducing atmosphere.

Functional protein sequences:

J Mol Biol. 2004 Aug 27;341(5):1295-315.

Estimating the prevalence of protein sequences adopting functional enzyme folds.

Axe DD.

The Babraham Institute, Structural Biology Unit, Babraham Research Campus, Cambridge CB2 4AT, UK. doug.axe@bbsrc.ac.uk

Proteins employ a wide variety of folds to perform their biological functions. How are these folds first acquired? An important step toward answering this is to obtain an estimate of the overall prevalence of sequences adopting functional folds.

[...]Starting with a weakly functional sequence carrying this signature, clusters of ten side-chains within the fold are replaced randomly, within the boundaries of the signature, and tested for function. The prevalence of low-level function in four such experiments indicates that roughly one in 10(64) signature-consistent sequences forms a working domain. Combined with the estimated prevalence of plausible hydropathic patterns (for any fold) and of relevant folds for particular functions, this implies the overall prevalence of sequences performing a specific function by any domain-sized fold may be as low as 1 in 10(77), adding to the body of evidence that functional folds require highly extraordinary sequences.

So atheists are in double jeopardy here. They don’t have a way to build the Scrabble letters needed for life, and they don’t have a way to form the Scrabble letters into meaningful words and sentences. Point out that the more research we do, the tougher the problem gets to solve for naturalists, and the more it looks like an effect of intelligence. Write out the calculations for them.

4) The best candidate to explain the sudden origin of the Cambrian era fossils was the Ediacaran fauna, but those are now recognized as not being precursors to the Cambrian fossils.

Science Daily reports on a paper from the peer-reviewed journal Science:

Evidence of the single-celled ancestors of animals, dating from the interval in Earth’s history just before multicellular animals appeared, has been discovered in 570 million-year-old rocks from South China by researchers from the University of Bristol, the Swedish Museum of Natural History, the Paul Scherrer Institut and the Chinese Academy of Geological Sciences.

[...]This X-ray microscopy revealed that the fossils had features that multicellular embryos do not, and this led the researchers to the conclusion that the fossils were neither animals nor embryos but rather the reproductive spore bodies of single-celled ancestors of animals.

Professor Philip Donoghue said: “We were very surprised by our results — we’ve been convinced for so long that these fossils represented the embryos of the earliest animals — much of what has been written about the fossils for the last ten years is flat wrong. Our colleagues are not going to like the result.”

Professor Stefan Bengtson said: “These fossils force us to rethink our ideas of how animals learned to make large bodies out of cells.”

The trend is that there is no evolutionary explanation for the body plans that emerged in the Cambrian era. If you want to make the claim that “evolution did it”, then you have to produce the data today. Not speculations about the future. The data we have today says no to naturalism. The only way to affirm naturalistic explanations for the evidence we have is by faith. But rational people know that we need to minimize our leaps of faith, and go with the simplest and most reasonable explanation – an intelligence is the best explanation responsible for rapid generation of biological information.

Conclusion

I do think it’s important for Christians to focus more on scientific apologetics and to focus their academic careers in scientific fields. So often I look at Christian blogs, and I see way too much G. K. Chesterton, Francis Chan and other untestable, ineffective jibber-jabber. We need to bring the hard science, and stop making excuses about not being able to understand it because it’s too hard. It’s not too hard. Everyone can understand “Who Made God?” by Edgar Andrews – start with that! Then get Lee Strobel’s “The Case for a Creator“. That’s more than enough for the average Christian on science apologetics. We all have to do our best to learn what works. You don’t want to be anti-science and pro-speculation like atheists are. I recommend reading Uncommon Descent and Evolution News every day for a start.

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A must-read series of posts on cosmic fine-tuning by Allen Hainline

There are four posts in the series, so far. I think Allen might be done, so I’m going to link to all four and snip something I like from each one.

The first post is on whether the fine-tuning is real, and whether a multiverse explains the fine-tuning so that there is no need for a cosmic Designer.

I just have to choose this quote from the atheist Stephen Hawking on the fine-tuning:

The remarkable fact is that the values of these numbers [i.e. the constants of physics] seem to have been very finely adjusted to make possible the development of life. For example, if the electric charge of the electron had been only slightly different, stars would have been unable to burn hydrogen and helium, or else they would not have exploded. It seems clear that there are relatively few ranges of values for the numbers [i.e. the constants of nature] that would allow for development of any form of intelligent life.

And from Luke Barnes, who I’ve mentioned before on this blog:

In my years of researching this topic, I’m amazed at how few scientists who have studied the fine-tuning details disagree with this core claim that the subset of life-permitting physics is a tiny fraction among possibilities. Since Luke Barnes is a top researcher on this topic, consider his input on the level of acceptance of the fine-tuning claim: “I’ve published a review of the scientific literature, 200+ papers, and I can only think of a handful that oppose this conclusion, and piles and piles that support it.[3]

And on the multiverse as a way to escape the fine-tuning:

The key issue though is that for the multiverse to be an adequate explanation for the fine-tuning it requires the conjunction of several hypotheses for which we lack any empirical evidence:

  1. A universe-generating mechanism that generates a plethora of universes
  2. That this mechanism doesn’t itself require fine-tuning
  3. The many-worlds interpretation of quantum physics
  4. The ability to widely vary constants in those universes. If you think that it’s a foregone conclusion that String Theory/M-Theory[8] will come to the rescue in this area, you should watch this video clip by Oxford physicist Roger Penrose where he exclaims that “it’s not even a theory … it’s a collection of hopes”.

Occam’s razor therefore does seem to favor design over the multiverse. When one accounts for the extensive problems in affirming premise 2 and how these multiverse theories make predictions incompatible with our universe, the hypothesis that God designed the physics of the universe to bring about life is more plausible.

Here’s the second post, where he explains the fine-tuning argument philosophically, and gives an example of one of the constants that has to be fine-tuned in order to support complex, embodied intelligence of any kind.

The cosmological constant:

The inference to design will be more easily recognized if we shed some light as to the specialness of the required values. Consider the size of the bull’s eye and wall based on just 1 parameter – the cosmological constant. There is a natural range for possible values for this constant because there are known contributions that are 10120times larger than the overall net value. (There is a near perfect but inexact cancellation of contributions accurate to 120 decimal places). Let’s use the most conservative numbers in the physics literature that indicate a fine-tuning to 1 part in 1053. If the cosmological constant, which governs the expansion rate of the universe, had been larger than its current value by this tiny fraction, then the universe would have expanded so fast that no stars or planets would have formed and therefore no life. If the value were smaller by this amount then the universe would have rapidly collapsed before the universe cooled sufficiently to allow for stable information storage which is required by any self-replicating system such as life.

In the third post, he responds to objections to the fine-tuning argument. One objection you hear from atheists who don’t understand the science is that any selection of constants and quantities is as likely as any other, so our life-permitting set is just random. Now, first off, there are only 10 to the 80 atoms in the visible universe, so if the cosmological constant is fine-tuned to 1 in 10 to the 120, it’s not rational to say “it just happened randomly”.

But here is Allen’s response:

However, the assumption that any set of constants is just as likely as any other is the very thing that we want to know. Starting off with that as an assumption begs the question against design. As Luke Barnes articulates in this excellent podcast dealing with responses to the fine-tuning claim, suppose we’re playing poker and every time I deal I get a royal flush. If this continues to happen, you become increasingly convinced that I’m likely to be cheating. If I responded to an accusation of cheating by just saying “well any set of 5 cards is just as likely as any other so you can’t accuse me of cheating” you would be rational to reject this explanation. The question is not “how likely is any set of 5 cards?” but rather “how likely is it I’m cheating if I just dealt myself 10 straight royal flushes?” This question accounts for the possibility that I’m cheating which would almost certainly be true in this scenario. So the right fine-question is “given the fine-tuning evidence, how likely is it that the constants were set at random?” The values for physical constants conform to a very particular pattern – that which supports life. The fact that we have so many finely-tuned constants makes it unlikely that they were all set at random (at least in the single universe scenario and I’ve already shown some of the problems/challenges in multiverse explanations.)

Every 5-card hand that you draw is equally unlikely, but the royal flush is the highest hand in the game and always wins. Every hand you draw is unlikely, but whatever you draw is overwhelmingly likely to not be a royal flush.

Finally, the fourth post deals with the objection that the constants and quantities could not have been other than they are.

He quotes physicist John Barrow giving 5 reasons why the constants can vary, and then this:

Even if the constants and laws of physics couldn’t vary, there is even more reason to think that there were many physically possible sets of initial conditions. Paul Davies states this emphatically:

“Even if the laws of physics were unique, it doesn’t follow that the physical universe itself is unique…the laws of physics must be augmented by cosmic initial conditions…there is nothing in present ideas about ‘laws of initial conditions’ remotely to suggest that their consistency with the laws of physics would imply uniqueness. Far from it…it seems, then, that the physical universe does not have to be the way it is: it could have been otherwise.[4]”

John A. Wheeler agrees: “Never has physics come up with a way to tell with what initial conditions the universe was started off. On nothing is physics clearer than what is not physics.”

The constants and quantities are not determined by physics. They were selected by whoever created nature in the first place.

So that’s the series. I noticed that he kept linking to this Common Sense Atheism podcast featuring famous cosmologist Luke Barnes. I grabbed it to listen this weekend, and you might want to get it, too. It’s over an hour. It seems like it is one stop shopping to understand common objections to the fine-tuning argument, and how strong each one is.

 

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Neil Shenvi lectures on the relationship between science and religion

Another great 42-minute lecture by Dr. Neil Shenvi.

Speaker bio:

As it says on the main page, my name is Neil Shenvi; I am currently a research scientist with Prof. Weitao Yang at Duke University in the Department of Chemistry. I was born in Santa Cruz, California, but grew up in Wilmington, Delaware. I attended Princeton University as an undergraduate where I worked on high-dimensional function approximation with Professor Herschel Rabitz. I became a Christian in Berkeley, CA where I did my PhD in Theoretical Chemistry at UC – Berkeley with Professor Birgitta Whaley. The subject of my PhD dissertation was quantum computation, including topics in quantum random walks, cavity quantum electrodynamics, spin physics, and the N-representability problem. From 2005-2010, I worked as a postdoctoral associate with Prof. John Tully at Yale where I did research into nonadiabatic dynamics, electron transfer, and surface science.

Outline slide: (Download the Powerpoint slides here)

Lecture:

Summary:

  • Science is often considered to be in opposition to religion, because it answers all the questions that religion asks
  • Thesis: 1) Science and religion are compatible, 2) Science provides us with good reasons to believe that God exists
  • Definition: what is science?
  • Definition: what is the scientific method?
  • Definition: what is religion?
  • Where is the conflict between science and religion, according to atheists?
  • Conflict 1: Definitional – faith is belief without evidence
  • But the Bible doesn’t define faith as “belief without evidence”
  • Conflict 2: Metaphysical – science presuppose naturalism (nature is all that exists)
  • First, naturalism is a philosophical assumption, not something that is scientifically tested or proved
  • Second, methodological naturalism in science doesn’t require us to believe in metaphysical naturalism
  • Conflict 3: Epistemological – science is the only way to know truth (scientism)
  • But scientism cannot itself be discovered by science – the statement is self-refuting
  • Conflict 4: Evolutionary – evolution explains the origin of life, so no need for God
  • Theists accept that organisms change over time, and that there is limited common descent
  • But the conflict is really over the mechanism that supposedly drives evolutionary change
  • There are philosophical and evidential reasons to doubt the effectiveness of mutation and selection
  • Evidence for God 1: the applicability of mathematics to the natural world, and our ability to study the natural world
  • Evidence for God 2: the origin of the universe
  • Evidence for God 3: the fine-tuning of the initial constants and quantities
  • Evidence for God 4: the implications of quantum mechanics
  • Evidence for God 5: the grounding of the philosophical foundations of the scientific enterprise
  • Hiddenness of God: why isn’t the evidence of God from science more abundant and more clear?
  • Science is not the only means for getting at truth
  • Science is not the best way to reach all the different kinds of people
  • There is an even deeper problem that causes people to not accept Christianity than lack of evidence
  • The deeper problem is the emotional problem: we want to reject God’s claim on our lives

He concludes with an explanation of the gospel, which is kinda cool, coming from an academic scientist.

I am a big admirer of Dr. Neil Shenvi. I wish we could clone him and have dozens, or even hundreds, like him (with different scientific specializations, of course!). I hope you guys are doing everything you can to lead and support our young people, and encouraging them to set their sights high and aim for the stars.

UPDATE: Dr. Shenvi has posted a text version of the lecture.

Related posts

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William Lane Craig posts full Vilenkin e-mail misrepresented by Krauss in their debate

First, Dr. Craig posted the e-mail from Vilenkin to Krauss, which Krauss used in his debate with Craig, with the parts Krauss omitted in bold:

Hi Lawrence,

Any theorem is only as good as its assumptions. The BGV theorem says that if the universe is on average expanding along a given worldline, this worldline cannot be infinite to the past.

A possible loophole is that there might be an epoch of contraction prior to the expansion. Models of this sort have been discussed by Aguirre & Gratton and by Carroll & Chen. They had to assume though that the minimum of entropy was reached at the bounce and offered no mechanism to enforce this condition. It seems to me that it is essentially equivalent to a beginning.

On the other hand, Jaume Garriga and I are now exploring a picture of the multiverse where the BGV theorem may not apply. In bubbles of negative vacuum energy, expansion is followed by cocntraction, and it is usually assumed that this ends in a big crunch singularity. However, it is conceivable (and many people think likely) that singularities will be resolved in the theory of quantum gravity, so the internal collapse of the bubbles will be followed by an expansion. In this scenario, a typical worldline will go through a succession of expanding and contracting regions, and it is not at all clear that the BGV assumption (expansion on average) will be satisfied.

I suspect that the theorem can be extended to this case, maybe with some additional assumptions. But of course there is no such thing as absolute certainty in science, especially in matters like the creation of the universe. Note for example that the BGV theorem uses a classical picture of spacetime. In the regime where gravity becomes essentially quantum, we may not even know the right questions to ask.

Alex

Now recall that Krauss excuses the selective editing of the e-mail in the debate by saying that it was “too technical” to include. Judge for yourself if the omitted lines are “too technical” or whether they were omitted in order to mislead people about the evidence for the beginning of the universe.

Dr. Craig comments:

Whoa! That puts a very different face on the matter, doesn’t it? Why didn’t Krauss read the sentence, “It seems to me that it is essentially equivalent to a beginning”? Because it was too technical? Is this the transparency, honesty, and forthrightness that Krauss extols? (By the way, Vilenkin’s criticism of these models is the same one that Vilenkin makes in his Cambridge paper: far from showing an eternal past, these models actually feature a universe with a common beginning point for two arrows of time.)

And why did Krauss delete Vilenkin’s caveat that the BGV theorem can, in his estimation, be extended to cover the case of an expanding and contracting model such as Garriga and Vilenkin are exploring? And why delete the remark that such a model is usually assumed to be incorrect? It’s evident that Vilenkin’s email was selectively edited to give it the spin Krauss wanted.

Some people told me that they thought that Dr. Craig needed to be a little less gracious with Krauss in the debate, but that comment takes Krauss on directly. Too bad most of the people who watch the debate will never know unless they see the original e-mail from Vilenkin that Craig posted.

Dr. Craig then wrote to Dr. Vilenkin about this misrepresentation and here is part of the reply:

The Aguirre-Gratton model can avoide singularities by postulating a small “initial” closed universe and then allowing it to evolve in both directions of time. I put “initial” in quotation marks, because Aguirre and Gratton do not think of it that way. But this model requires that a very special condition is enforced at some moment in the history of the universe. At that moment, the universe should be very small and have very low entropy. Aguirre and Gratton do not specify a physical mechanism that could enforce such a condition.

Carroll and Chen claim that the universe did not have to be small at that special moment. But in my recent paper I show that in this case singularities are unavoidable.

[...]I think you represented what I wrote about the BGV theorem in my papers and to you personally very accurately.

Now I don’t want anyone to get the idea that all atheists are like Krauss. I distinctly remember another atheist named Anthony Flew debating Dr. Craig and a questioner from the audience asked him why not prefer speculative cosmologies like the eternally oscillating model. Dr. Flew (unlike Dr. Krauss) was honest – he said that we have to accept the science we have today based on the evidence we have today. Dr. Krauss is not willing to accept the science we have today and the evidence we have today. That’s the difference. This is a failing of Dr. Krauss’ will and intellect. He simply cannot bring himself to accept what science has shown, if it impacts his autonomy in any way. He would rather mislead himself and others with speculations rather than face reality.

Watch the whole debate – see for yourself

I’ll re-state the relevant part of my Craig-Krauss debate summary below. The summary has the full video.

The segment from 52:18 to 57:12 about the Vilenkin e-mail on the BVG theorem is a must-see. Krauss is standing up and gesticulating while Craig is calmly trying to quote a paper by Vilenkin that shows that Krauss is misrepresenting Vilenkin. Krauss constantly interrupts him. After a while, when Craig exposes him as having misrepresented Vilenkin and gets him to admit that all current eternal models of the universe are probably wrong, he quietens down and can’t even look at Craig in the face.

Cosmological argument:

  • Craig: The e-mail says any universe that is expanding, on average, requires a beginning
  • Craig: There are two models – Aguirre & Gratton and Carroll & Chen – where there is a period of contraction before the expansion
  • Craig: The two models are the ones cited in the e-mail that Dr. Krauss showed
  • Craig: In the very paper by Vilenkin that I cited, he says that both of those models don’t work
  • Krauss: (agitated and interrupting) Vilenkin said that they have to make an assumption about entropy that they have no rationale for
  • (as Craig starts to talk Krauss makes an exaggerated, disrespectful gesture and sits down in a huff)
  • Craig: Yes, an unwarranted assumption means that they don’t have EVIDENCE for their theories being correct
  • Krauss: (agitated and interrupting) “All the evidence suggests that the universe had a beginning but WE DON’T KNOW!!!!!!!” (raising his voice)
  • Craig: I’m not saying that we know that the universe had a beginning with certainty
  • Craig: I am saying that the beginning of the universe is more probably true than false based on the evidence we have
  • Craig: And you  agree with me about that – you think the universe had a beginning
  • Krauss: (agitated and interrupting) (Unintelligible)
  • Moderator: One at a time
  • Craig: In your Vilenkin e-mail slide, at the end of the paragraph where the two models are mentioned that Vilenkin specifically shows…
  • (I am guessing that Craig is going to ask why so much of what Vilenkin wrote has been cut out of the e-mail that Krauss showed)
  • Krauss: (agitated and interrupting) Because it was technical…
  • Moderator: Lawrence! Hang on a sec!
  • Craig: He specifically shows that these models are not past eternal, and that they require a beginning just like the others…
  • Krauss: (agitated and interrupting) We can do the math if you want
  • Craig: Now wait. I couldn’t help notice that there on your slide there was a series of ellipsis points indicating missing text…
  • Krauss: (agitated and interrupting) “Yeah, because it was technical!”
  • Craig: “I wonder what you deleted from the original letter”
  • Krauss: (agitated and interrupting) “I just told you!”
  • Craig: “Now wait. Could it have been something like this:  (reads a quote from Vilenkin) ‘You can evade the theorem by postulating that the universe was contracting prior to some time. This sounds as if there is nothing wrong with having contraction prior to expansion. But the problem is that a contracting universe is highly unstable. Small perturbations would cause it to develop all sorts of messy singularities, so it would never make it to the expanding phase.’
  • Craig: “That’s Vilenkin.”
  • Krauss: “In this paper, that’s absolutely right”
  • Krauss: But it’s ok for theories to assume things that we know are wrong – they are still good theories – it’s unknown
  • (Craig turns away and looks through his papers)
  • Craig: “Isn’t it true that the only viable quantum gravity models on order today involve a beginning – have a finite past?”
  • Krauss: “No”
  • Craig: “Well, can you give us one then”
  • Krauss: (talks about a variety of possible eternal models) “In my experience in science, all of them are probably wrong”
  • Krauss: “You know most theories are wrong, which is why, you know, it’s hard”
  • Craig: “Right”

Krauss accused Dr. Craig of misrepresenting science many times in his three Australia debates, but now we know the truth about who misrepresented science.

UPDATE: This whole episode made me think of a lecture by famous physicist Richard Feynman.

Excerpt:

The first principle is that you must not fool yourself–and you are the easiest person to fool. So you have to be very careful about that. After you’ve not fooled yourself, it’s easy not to fool other scientists. You just have to be honest in a conventional way after that.

I would like to add something that’s not essential to the science, but something I kind of believe, which is that you should not fool the layman when you’re talking as a scientist. I am not trying to tell you what to do about cheating on your wife, or fooling your girlfriend, or something like that, when you’re not trying to be a scientist, but just trying to be an ordinary human being. We’ll leave those problems up to you and your rabbi.  I’m talking about a specific, extra type of integrity that is not lying, but bending over backwards to show how you are maybe wrong, that you ought to have when acting as a scientist. And this is our responsibility as scientists, certainly to other scientists, and I think to laymen.

Now given what Krauss did in the debate, it seems to me that he is not in agreement with Feynman.

UPDATE: Dr. Craig reports that Dr. Krauss refused to let the organizers live-stream the three Australia debates, as well as refusing to let the Australian Broadcasting Corporation live-broadcast the three debates.

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