Atheist Luke Muehlhauser interviews well-respect cosmologist Luke Barnes about the fine-tuning argument, and the naturalistic response to it.
Luke M. did a good job explaining what was in the podcast. (I wish more people who put out podcasts would do that).
Details:
In one of my funniest and most useful episodes yet, I interview astronomer Luke Barnes about the plausibility of 11 responses to the fine-tuning of the universe. Frankly, once you listen to this episode you will be better equipped to discuss fine-tuning than 90% of the people who discuss it on the internet. This episode will help clarify the thinking of anyone – including and perhaps especially professional philosophers – about the fine-tuning of the universe.
The 11 responses to fine-tuning we discuss are:
“It’s just a coincidence.”
“We’ve only observed one universe, and it’s got life. So as far as we know, the probability that a universe will support life is one out of one!”
“However the universe was configured, evolution would have eventually found a way.”
“There could be other forms of life.”
“It’s impossible for life to observe a universe not fine-tuned for life.”
“Maybe there are deeper laws; the universe must be this way, even though it looks like it could be other ways.”
“Maybe there are bajillions of universes, and we happen to be in one of the few that supports life.”
“Maybe a physics student in another universe created our universe in an attempt to design a universe that would evolve intelligent life.”
“This universe with intelligent life is just as unlikely as any other universe, so what’s the big deal?”
“The universe doesn’t look like it was designed for life, but rather for empty space or maybe black holes.”
“Fine-tuning shows there must be an intelligent designer beyond physical reality that tuned the universe so it would produce intelligent life.”
Download CPBD episode 040 with Luke Barnes. Total time is 1:16:31.
I’m going to put the list of resources for the podcast that Luke M. mentioned in his post, but without the actual hyperlinks. It saves me having to type up a summary. If you want to click the links that I removed, go over to Common Sense Atheism and the links are there.
Links for things we discussed:
Fine-tuned universe
Cosmological constant
Miss Marple
Other forms of life and Daleks
Elliot Sober
Cosmic inflation
The graceful exit problem
Carr and Rees, “The Anthropic Cosmological Principle and the Structure of the Physical World” (1979)
David Lewis’ modal realism
Boltzmann’s multiverse
Roger Penrose argues that some modern multiverse theories face the same problem that Boltzmann’s multiverse faces in The Road to Reality.
Everett’s multiverse
Wheeler – At Home in the Universe
Thorne-Hawking-Preskill bet
Edward Robert Harrison
Luke responds to PZ Myers
You can find some good talks by Polkinghorne and Ellis on fine-tuning at the Faraday Institute’s multimedia page.
William Lane Craig, “Design and the Anthropic Fine-Tuning of the Universe“
Robin Collins, “The Teleological Argument“
Good stuff: Davies – The Goldilocks Enigma; Rees – Just Six Numbers; Barrow – The Constants of Nature; Barrow & Tipler – The Anthropic Cosmological Principle; Leslie – Universes; George Ellis articles.
Fred Adams and Luke’s critique
Luke’s critique of Hector Avalos
Luke’s critique of Victor Stenger: part 1 and part 2
Luke’s critique of Hugh Ross
Luke’s critique of William Lane Craig: part 1 and part 2
I thought the funniest part was the Natalie Portman part. Boy, do I wish more atheists would listen to this podcast and understand what the fine-tuning argument is actually about. Luke M. gave Luke B. a ton of time to talk. There is a very good explanation of some of the cases of fine-tuning that I talk about most on this blog – the force of gravity, the strong force, etc. as well as many other examples. Dr. Barnes is an expert, but he is also very very easy to listen to even when talking about difficult issues. Luke M. is very likeable as the interviewer.
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.
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.
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.
Dr. Graham Oppy, the moderator, is a well-known atheist philosopher. He let Dr. Krauss speak for 21 minutes and 40 seconds, which is why my summary of Krauss is so long.
The video:
Summary
After careful consideration, I decided not to be snarky at all in this summary. What you read below is what happened. There may be some small mistakes, but I will fix those if people tell me about them. I also included some quotes and timestamps for the more striking things that Dr. Krauss said.
The debate itself starts at 4:50 with Dr. Craig’s opening speech. He does use slides to show the structure of his arguments.
Dr. Craig’s opening speech. (4:50)
The kalam cosmological argument:
God is the best explanation of the origin of the universe
The Borde Guth Vilenkin theorem supports the absolute beginning of the universe
Even if our universe is part of a multiverse, the multiverse itself would have to have an absolute beginning
Speculative cosmologies try to challenge the Big Bang theory, but none of them – even if true – can establish that the past is eternal
Only two types of things could explain the origin of spece, time, matter and energy – either abstract objects or minds
Abstract objects do not cause effects, but minds do cause effects (we do it ourselves)
A mind is the best explanation for the origin of the universe
The unreasonable effectiveness of mathematics:
The underlying structure of nature is mathematical – mathematics is applicable to nature
Mathematical objects can either be abstract objects or useful fiction
Either way, there is no reason to expect that nature should be linked to abstract objects or fictions
But a divine mind that wants humans to understand nature is a better explanation for what we see
The cosmic fine-tuning for the existence of intelligent life
There are two kinds of finely-tuned initial conditions: 1) cosmological constants and 2) quantities
These constants and quantities have to be set within a narrow range in order to permit intelligent life
There are three explanations for this observation: law, chance or design
Law is rejected because they are put in at the beginning or matter – they don’t emerge from matter
Chance must be rejected, because they odds are just too long unless you appeal to a world-ensemble
We do not observe what the world ensemble hypothesis predicts that we should observe
Design is the best explanation for finely-tuned constants and quantities
The existence of objective moral values and duties
Our experience of morality (values and duties) is that it is objectively real and incumbent on us
When someone goes into a classroom and shoots at innocent children, that is objectively wrong
On naturalism, moral values and moral duties do not exist – they are conventional and variable by time and place
The best explanation for the existence of objective moral values and duties is that God exists
The historicity of the resurrection of Jesus
There are three widely-accepted facts that are best explained by the resurrection hypothesis
1) the empty tomb, 2) the post-mortem appearances, 3) the early church’s belief in the resurrection
Naturalistic attempts to explain these 3 boilerplate facts fail
The best explanation of the 3 minimal facts is that God raised Jesus from the dead
The immediate experience of God
Belief in God is a “properly basic” belief – rational even without arguments because of experience of God
Seems to be saying that logical arguments can prove false things “it’s nonsense”
Dr. Craig distorted a podcast that some group made on pain receptors
Dr. Craig’s faith is so strong that it causes him to distort what this group said
Discussion: (44:35)
I will not be summarizing everything that was said, just a few main points.
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”
I noticed that a huge number of atheist web sites are taking the Vilenkin quote that Krauss used out of context, like this one and this one. There are probably a lot more of them like that, which I think is interesting. That’s why we have these debates, I guess. To set the record straight about who accuses people of being dishonest, and who is actually dishonest.
Fine-tuning:
Krauss tried to argue that he had explained the fine-tuning with the Higgs particle, but Dr. Craig said that only applied to the cosmological constant, not all the other examples of fine-tuning. Krauss said that it wasn’t impressive that this universe permitted life and that “It would have been much more surprising if we evolved in a universe in which we couldn’t live”. Krauss argued the fine-tuning was only for “Life like us”. But Dr. Craig explained that the fine-tuning is what allows us to have the basics of any kind of life, like slow-burning stars, chemical diversity, etc. – things that are required for basic minimal life functions in any living system. Craig said that he was working with the current physical laws of this universe (F = ma, etc.) and that he was looking at what changed if we changed those even slightly. Krauss tried to say that if he changed things like the mass of particles then the strength of forces would change. (But the forces aren’t laws!) Krauss argued that the cosmological constant would be even better for life if it was zero, and Craig said that the life permitting range did include zero, but that the range of life-permitting values was narrow.
Jesus’ existence:
Craig reponded to the mystery religions charge, the charge that the evidence for the minimal facts is too late/too weak, the charge that grief visions explained the evidence better, and Hume’s argument against miracles. Craig brought up the early creed from 1 Cor 15:3-7 and explained to Krauss that it was 5 years after the events, and that Jewish standards of oral transmission were strong enough to ensure that the creed was reliable, and most of the eyewitnesses would still have been alive.
Audience Q and A: (1:21:09)
The first topic is the grounding of morality. Krauss agrees that there is no objective morality and no objective moral oughts. He also said that that standards of behavior are arbitrary, and that they change over time and they are adopted for promoting social order. Dr. Craig pressed the point that science itself would collapse without ethical values. It assumes them, but cannot ground them.
The next topic was free will. Krauss is a determinist. Craig asked him how he could reconcile moral responsibility with determinism.
The next topic was the effectiveness of mathematics. Krauss didn’t have an explanation for it and didn’t think it needed one. Then they got into whether the Genesis has been verified by science and whether it is meant to be taken literally.
The next topic was whether philosophy makes any progress. Craig gave the example of verificationism being rejected as too narrow, and self-refuting. Krauss: “I’m going to come to the defense of philosophy for the first time”. Craig: “That’s amazing!” Krauss said that science provides new knowledge. Craig said there were some things that could be known apart from science.
WINTERY KNIGHT 