A Thick Layer: A Fine-Tuned Critique of Arvin Ash

Arvin Ash is an engineer with a YouTube channel. He recently posted a video titled “Is God in Physics? Fine Tuning Scrutinized“. It gets almost everything wrong: history, philosophy, science, and fine-tuning. All quotes from the video, unless noted otherwise.

A. Motion in the heavens

Until 350 years ago, there was a distinct demarcation between what people observed on Earth and what people saw up in the sky. There did not seem to be any connection. Things that happened on Earth could at least be seen and explained at least in terms of cause and effect. The Heavens seemed to be an utter mystery. The motions of the planets, though predictable, did not appear to follow the same patterns as objects here on Earth. To many this was the sign of the hand of a Creator. It must be God that ruled over the universe, controlling the movement of these heavenly bodies, and to gaze at the stars was to bear witness to the majesty of God’s design. [0:15]

We’re off to a terrible start. The Heavens were not an “utter mystery” to the ancients – Aristotle’s physics included the heavens. The planets and stars behaved differently to Earthly elements (earth, water, air, fire) because they were made out of different stuff.

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Doing cosmology with a brain

A favourite XKCD:

Made out of Meat

Here’s a few idle, Friday afternoon thoughts. I study distant galaxies. I use mathematical models of the laws of nature (and a supercomputer) to try to predict the properties of light emitted by and scattered through swirling vortices of matter, each containing a thousand trillion trillion trillion tons of stars, gas and dark matter, almost a trillion trillion kilometers away. My discipline – cosmology – has taken as its object of study the universe as a whole. And we’re doing pretty well, thanks for asking. I’d like to think that I am an evidence collecting, theory discovering, model investigating, equation solving (with a little help from my computer) machine.

And then I hear a talk from a biologist. I am reminded that I’m a fighting, fleeing, feeding, and reproducing machine. The lump of stuff in my head was produced by causes that “see” survival and reproduction. My brain is the control centre of a biological organism, and there seems to be precious little overlap between survival, reproduction and astrophysical ability. (Unless my astrophysical brain has made me so attractive to the ladies that it significantly increases my chances of reproduction. I’ll ask my wife.) An accurate mental picture of the world, formed using mostly reliable senses and the ability to reason logically, creatively and flexibly, seems useful to survival. But to use a brain to do cosmology? Really? (If you haven’t read Terry Bisson’s wonderful short essay “They’re made out of meat“, then do it now: “Thinking meat! You’re asking me to believe in thinking meat!”.)

A parable. Suppose I call Toyota customer services.

Me: Hi there. I own a 1993 Toyota Camry. I have a question.

Toyota: Certainly, sir. Is the car running well, getting you from A to B in comfort?

Me: Sure. It’s doing all that nicely. I was thinking about using it to drive to the moon.

Toyota: … Right … Wouldn’t recommend that, Mr Barnes. No … uh … not really in the user manual, I’m afraid. Not what it’s made for.

Suppose I find a customer support label on the back of my brain.

Me: Hi there. I own and operate one of your brains. I have a question.

Support: Certainly, sir. Is it operating your body, correctly? Are you getting enough food? Have you found a mate?

Me: Sure. It’s doing all that nicely. I was thinking about using it to do theoretical physics, discover the fundamental laws of the universe and use them to understand the structure and evolution of the universe and all its contents.

Support: … Right … Wouldn’t recommend that, Mr Barnes. No … uh … not really in the user manual, I’m afraid. Not what it’s made for.

Let’s be clear about the point I’m making here. I don’t doubt that physicists in general and cosmologists in particular have discovered true facts about the universe. It’s just a tad amazing that we can do that sort of things with our brains. (We use computers and telescopes as well, of course, but they too are the products of human brains). To extend the analogy, it’s as if I find myself standing on the moon, wondering how I got there. And as I look around, all I can see is a 1993 Toyota Camry. It’s not that I doubt where I am; I’m wondering how I got here in that! I’m not asking: how do I know that our investigation of the universe is successful? I’m asking: why is our investigation of the universe successful? How does fighting/fleeing/feeding/reproducing machine manage to do theoretical physics?

Perhaps the boring answer is the right one: we do it bit by bit. If we view science as extended and refined common sense, then maybe we can understand how a brain “made for” understanding local terrestrial environments is able to understand the universe. We don’t directly grasp the universe, of course. We rely on mental pictures and analogies. Mathematical models of the universe are perhaps analogies with equations. Having a mental picture of the world is useful. Just add curiosity and get practicing.

It seems like the same problem arises for mathematics – how does a brain manage to investigate such abstract ideas as those of pure mathematics? The same answer suggests itself: abstract thinking is useful. Just add curiosity and get practicing.

The universe is easy

We seem to need another ingredient in this explanation. That a brain can do theoretical physics and cosmology suggests not only that it is a remarkably adaptable, programmable thing, but also that the universe is an easier problem than we might have expected. A great example of this is the so-called cosmological principle. (I discuss this in more detail in my Australian Physics article here.)

That the universe is rationally analysable at all, that there is order and reason waiting for us in the mathematical structure of the universe, is a remarkable fact. The intellectual problem we are presented with in nature is, in a very real and precise sense, solvable.  It is one thing that the universe exemplifies such beautiful mathematics as Lagrangian dynamics; it is another, a fortiori, that the Lagrangians that describe our universe display numerous and deep symmetries. The universe is a complicated place, and the mathematics that describes it must be complicated at some level. The remarkable thing is that the complication is on top; there is simplicity underneath. To be more precise, the laws of nature are simple, their solutions can be complicated. Newton’s law of gravitation is simple, but for even three bodies, its solution cannot be written down analytically.

In physics’s search for the ultimate laws of nature, many physicists wouldn’t accept a proposed fundamental theory unless it were simple, elegant, and beautiful. Paul Dirac went so far as to say that “it is more important to have beauty in one’s equations than to have them fit experiment”. It follows that physics cannot explain why the laws of nature are simple, elegant, and beautiful. Now there’s a thought for the weekend.

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Carroll’s five replies to the fine-tuning argument: Number 1

Last time, I started a review of the Carroll vs. Craig debate with a (mostly historical) overview of the back-and-forth about the beginning of the universe for the last 90 years of modern cosmology. Here, I’ll have a look at fine-tuning. I should start by saying how much I enjoyed the debate. They should do it again some time.

In his speeches, Sean Carroll raised five points (transcript) against the fine-tuning of the universe for intelligent life as an argument for the existence of God. I want to have a look at those five. Carroll (here) and Craig (here, here and here) had a few points to make post-debate, too.

Here is fine-tuning reply number one:

First, I am by no means convinced that there is a fine-tuning problem and, again, Dr. Craig offered no evidence for it. It is certainly true that if you change the parameters of nature our local conditions that we observe around us would change by a lot. I grant that quickly. I do not grant therefore life could not exist. I will start granting that once someone tells me the conditions under which life can exist. What is the definition of life, for example? If it’s just information processing, thinking or something like that, there’s a huge panoply of possibilities. They sound very “science fiction-y” but then again you’re the one who is changing the parameters of the universe. The results are going to sound like they come from a science fiction novel. Sadly, we just don’t know whether life could exist if the conditions of our universe were very different because we only see the universe that we see.

“Interesting” Games

Is the debate over the definition of life a problem for fine-tuning? Sean and I had a brief discussion on this point during my talk at the UCSC Summer School on Philosophy of Cosmology. My response was (roughly) as follows.

Consider chess. In particular, I’m wondering whether minor changes to the laws of chess would result in a similarly interesting game. Wait a minute, you say, you haven’t defined “interesting”. In fact, different people are going to come up with different definitions of interesting. So how can we know whether a game is interesting or not?

It’s a good point, but instead of considering this question in abstract, consider this particular example. Change one word in the rules of chess: instead of “Knights may jump over other pieces”, we propose that “Bishops may jump over other pieces”. If we were to rewrite the 530 page “Silman’s Complete Endgame Course“, we would need just one page, one paragraph, two sentences: “White bishop moves from f1 to b5. Checkmate.”

My claim is that this particular case is so clear that by any definition of interesting, this is not an interesting game. The game is no more interesting than tossing a coin to see who goes first. It is too simple, too easy.

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Did the Universe Have a Beginning? – Carroll vs Craig Review (Part 1)

It’s been a while, but I’ve finally gotten around to jotting down a few thoughts about the Sean Carroll vs. William Lane Craig debate. I previewed the debate here (part one, two, three, four). I thoroughly enjoyed the debate. Future posts will discuss a few of the philosophical questions raised by the debate, but I’ll briefly discuss some of the science in this point. (I didn’t manage to record my talk a few weeks ago, but this post summarises it.)

Firstly, I want to refer you to the much greater expertise of Aron Wall of UC Santa Barbara. I’ll list them all because they’re great.

• Did the Universe Begin? I: Big Bang Cosmology
• Did the Universe Begin? II: Singularity Theorems
• Did the Universe Begin? III: BGV Theorem
• Did the Universe Begin? IV: Quantum Eternity Theorem
• Did the Universe Begin? V: The Ordinary Second Law
• Did the Universe Begin? VI: The Generalized Second Law
• Did the Universe Begin? VII: More about Zero Energy
• Did the Universe Begin? VIII: The No Boundary Proposal
• Did the Universe Begin? IX: More about Imaginary Time
• Fuzzing into existence

(I’m on the “astrophysics” end of cosmology. The beginning of the universe probes the “particle and plasma and quantum gravity and beyond” end of cosmology. I know the field, but not as well as someone like Wall or Carroll.)

No one expects the beginning of the universe!

Regarding the scientific question of the beginning of the universe, here is how I see the state of play. Cosmologists don’t try to put a beginning into their models. For the longest time, even theists who believed that the universe had a beginning acknowledged that the universe shows no sign of such a beginning. We see cycles in nature – the stars go round, the sun goes round, the planets go round, the seasons go around, generations come and go. “There is nothing new under the sun”, says the Teacher in Ecclesiastes. Aristotle argued that the universe is eternal. Aquinas argued that we cannot know that the world had a beginning from the appearance of the universe, but only by revelation.

So when a cosmic beginning first raised its head in cosmology, it was a shock to the system. Interestingly, theists didn’t immediately jump on the beginning as an argument for God. Lemaître, one of the fathers of the Big Bang theory and a priest, said:

“As far as I can see, such a theory [big bang] remains entirely outside any metaphysical or religious question.”

In 1951, Pope Pius XII declared that Lemaître’s theory provided a scientific validation for existence of God and Catholicism. However, Lemaître resented the Pope’s proclamation. He persuaded the Pope to stop making proclamations about cosmology.

The philosophical defence of the argument from the beginning of the universe to God (the Kalam cosmological argument) starts essentially with Craig himself in 1979, half a century after the Big Bang theory is born.

In fact, the more immediate response came from atheist cosmologists, who were keen to remove the beginning. Fred Hoyle devised the steady state theory to try to remove the beginning from cosmology, noting that:

“… big bang theory requires a recent origin of the Universe that openly invites the concept of creation”. His steady-state theory was attacked “because we were touching on issues that threatened the theological culture on which western civilisation was founded.” (quoted in Holder).

Tipping the Scales

But what of the beginning in the Big Bang model? Singularities in general relativity weren’t taken seriously at first. Einstein never believed in the singularities in black holes. Singularities were believed to be the result of an unphysical assumption of perfect spherical symmetry. In Newtonian gravity, a perfectly spherical, pressure-free static sphere will collapse to a singularity of infinite density. However, this is avoided by the slightest perturbation of the sphere, or by the presence of pressure. A realistic Newtonian ball of gas won’t form a singularity, and the same was assumed of Einstein’s theory of gravity (General Relativity).

The next 80 years of cosmology sees the scales tipping back and forth, for and against the beginning.

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Next Friday at the Epping Creative Centre, Sydney: “What Happened at the Big Bang?”

I’ve been a bit quiet around here, lately. Travel is my excuse. I’m currently in Cambridge, collaborating with a few colleagues on a project. I’ll be back in Sydney next week, so if you’re near Epping on Friday 4th July 2014, why not come along to hear me speak at the Astronomical Society of NSW:

“What Happened at the Big Bang?”

Friday 4th July 2014 – 8:00pm
Topic: What happened at the Big Bang?
Speaker: Dr Luke Barnes, University of Sydney
Venue: Epping Creative Centre – 26 Stanley Road, Epping

Abstract:
Was the big bang the beginning of the universe? Does the big bang represent the beginning of time itself? This is an age-old question, and has been remarkably informed by modern cosmology.

I will answer this question once and for all.

I will follow the theorems, evidence and hints that lead us back in time. In particular, I will discuss the expansion of the space, the physics of the very early universe, the recent BICEP2 results and cosmic inflation, the effect of quantum physics, and the reason (or one of them) why Stephen Hawking is famous.

Biography:
Dr Luke A. Barnes is a postdoctoral researcher at the Sydney Institute for Astronomy. After undergraduate studies at the University of Sydney, Dr. Barnes earned a scholarship to complete a PhD at the University of Cambridge. He worked as a researcher at the Swiss Federal Institute of Technology (ETH), before returning to Sydney in 2011. He has published papers on galaxy formation and cosmology, and recently has taken an interest in the fine-tuning of the universe for intelligent life. He blogs at letterstonature.wordpress.com.

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Have cosmologists lost their minds in the multiverse?

The Conversation has published an article of mine, co-authored with Geraint Lewis, titled “Have cosmologists lost their minds in the multiverse?“. It’s a quick introduction to the multiverse in light of the recent BICEP2 results. Comments welcome!

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Cosmology Q and A – Australian Physics article

My article “Cosmology Q & A” has been published! It appeared in the magazine Australian Physics, 51 (2014) 42-6 and is reproduced here with permission. After a brief overview of modern cosmology, it (tries to) answer the following questions:

1. Is space expanding, or are galaxies just moving away from us?
2. Is everything getting bigger?
3. Ordinary matter and radiation cause the expansion of the universe to decelerate. But our universe is accelerating! How? What is the universe made of?
4. Dark Energy? Is that like Dark Matter?
5. How big is the universe?
6. How big is the universe really?
7. If the universe were finite, could I see the back of my own head?
8. Is space expanding faster than the speed of light?
9. Are there galaxies moving away from us at more than the speed of light?
10. Light from distant galaxies is observed to be redshifted. Is this because the expansion of space stretches the wavelength, or because is it a Doppler shift due to the recession of the galaxy?
11. Does the universe have zero total energy?
12. Energy is not conserved!? Shouldn’t that send shivers up the spine of any physicist?
13. The very universe, we are told, began in thermal equilibrium. How did equilibrium establish itself so quickly?
14. How does the initially smooth universe we see in the CMB become today’s universe of stars and galaxies?

As before, further questions in the comments are always welcome.

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Carroll vs. Craig (4): On Nothing

More on the upcoming Carroll vs. Craig dialogue (previously, one, two, three). I have some leftover business from my previous post on the contingency argument for the existence of God. It concerns the question why is there something something rather than nothing?, a question I’ve discussed on a few previous occasions.

The Question

The question “why is there something something rather than nothing?” is not an argument, obviously. It’s a question. It’s relationship to the cosmological argument for the existence for God is as an entree, a taster. It’s supposed to get you thinking about existence.

Imagine two parties. At one is everything that actually exists (or has existed) – the “actual” party. At the other, everything that could exist – the “possible” party. Horses are at both parties, unicorns only the possible party. Why? Because of something at the actual party, in this case the evolutionary ancestors of the horse. When something moves from possible to actual, it’s because of an invitation from the actual party. Those in the possible party can’t crash the actual party. They don’t exist, and so don’t have any causal powers, so can’t make anything actually happen.

So this actual party – did everyone get their invitation off someone else? Is there an infinite regress of inviters? It can’t form a loop – I invite you and you invite me – because that’s just crashing the party. Could there be a party where everyone must be invited by someone who’s already there? Why is anyone at the party? Why does anything exist?

Not the Question

Aside: The question is not: “something came from nothing. How could that happen?”, to which the answer is supposedly: because God can make something out of nothing. That confuses the contingency argument with the Kalam argument. The question is “Why is there something rather than nothing?”. The answer is: God is a necessary being, so it is not possible for there to be nothing. God must exist.

Nothing, Naturally

Carroll discusses the question “why is there something rather than nothing?” in this blog post. Amongst other things, he discusses the claim that “nothingness is uniquely natural”, so that we need some special reason why something exists. He argues that we have no basis for such a conclusion, as our intuitions for naturalness and simplicity are based on our experience in this world, and so don’t automatically apply to the universe itself.

However, most versions of the cosmological argument don’t explicitly appeal to the naturalness of nothing. Carroll, following Grunbaum, discusses Swinburne. In Grunbaum’s paper “Why is There a World AT ALL, Rather Than Just Nothing?”, he quotes Swinburne: “It remains to me, as to so many who have thought about the matter, a source of extreme puzzlement that there should exist anything at all” (pg. 336). I think, however, they’ve missed the point of what Swinburne is saying. (I say this with some trepidation. Grunbaum is a professional philosopher, and something of a legend. Fools rush in …)

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Some cosmological introductions …

I don’t know who Rob Sheldon is, but he doesn’t know much about cosmology. He recently was quoted in this post at uncommondescent.com regarding the geometry of the universe. If I lecture cosmology this year, I’ll set this passage as an assignment: find all the mistakes. It gets more wrong than right. I have an article for “Australian Physics” on common questions about cosmology that I’ll post here once it’s out (a fortnight, maybe). In the meantime, I’ll try to clear up a few things.

The discussion of the mathematics of curvature (flat, positive, negative) is about right. It’s when he discusses the universe that things go wrong.

It takes a lot of effort to find any curvature at all, and certainly it is difficult to get good agreement between different types of measurement.

Nope. That’s why it’s called the “concordance model of cosmology” – because the different measurements converge on the same set of cosmological parameters. For example, this plot.

… a “closed” universe that collapses back down to itself …

A common error. In a matter and radiation-only universe, closed implies collapsing. A cosmological constant and/or dark energy changes this: closed vs. open no longer divides collapse vs. expand forever. Here is the plot you’ll need, from John Peacock’s marvellous Cosmological Physics.

… one would like it to have positive curvature to avoid infinities …

Flat and negatively curved universes can be finite. A flat 3-torus, for example, is finite, unbounded and has a flat geometry. Einstein’s general relativity constrains the geometry of the universe but not its topology.

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Sean Carroll vs William Lane Craig: A Preview

On February 21-22 (2014), Sean Carroll and William Lane Craig will debate at the Greer-Heard Forum, at the New Orleans Baptist Theological Seminary. The topic is “God and Cosmology: The Existence of God in Light of Contemporary Cosmology”. For a number of reasons, I have high hopes for this one. Here’s why.

I (mostly) like the format

We start with a dialogue between the two parties, for 1.5 hours. As a spectator, I prefer the debate format. While a dialogue sounds like a friendly chat rather than a confrontation, in practice it unfairly unfavors the rude and the loud. We are at the mercy of the disciplinary skill of the moderator. However, this one shouldn’t be too bad. Craig will let his opponent talk, and I get the same impression from Carroll.

Given the list of things I’d like them to discuss, as I’ll discuss in future posts, I’m hoping that each party gets an opening statement of at least 20 minutes. They both have a lot to say about this topic, and need the time to present their case thoroughly.

The next day we’re back with 4 speakers, each with an hour that includes responses from Carroll and Craig. That’s a very interesting arrangement and I’m keen to see how it works in practice. The day rounds out with concluding comments from the two debaters.

Good choice of debaters

I’ve listened to a number of William Lane Craig’s debates and the best ones are usually against other philosophers, for this reason. The topic is God, or at least something closely related to the almighty. In any argument for or against the existence of God, at least one of the premises must be metaphysical. So against, say, a scientist, Craig can absorb a lot of the scientific expertise of his opponent and focus on the (often unstated) philosophical assumptions behind their remarks. The debate moves to matters philosophical, which gives Craig the home advantage. Some of Craig’s opponents know less than nothing about philosophy; what they think they know about philosophy is wrong. On the other hand, Craig knows enough of the science that is relevant to his arguments to be able to defend the scientific premises against a philosopher.

Carroll has an undergraduate philosophy minor and as a grad student in astrophysics at Harvard, sat in on courses with John Rawls and Robert Nozick. His blog posts and articles show a familiarity with and respect for philosophical issues. Carroll is close to the ideal opponent for this debate, as he should be able to hold his own on matters philosophical, whilst holding a substantial advantage on matters cosmological.

Good Choice of Respondents

I’m guessing that Craig will defend three of his usual five arguments – the Kalam cosmological argument from the beginning of the universe, the contingency argument, and the design argument from the fine-tuning of the universe for intelligent life. The contingency argument doesn’t rely on any particular scientific theories, so Craig doesn’t need any particular backup on that front. For the Kalam cosmological argument, his scientific case for the premise “the universe has a beginning” has been provided in recent times by James Sinclair. In particular, Craig’s most sophisticated defence of the argument in recent times is in the The Blackwell Companion to Natural Theology, which was co-written with Sinclair. Sinclair is a Warfare Analyst with a masters in cosmology, so his credentials are slightly unorthodox.

Also writing in the The Blackwell Companion to Natural Theology is Robin Collins, a philosopher with a background in physics. He has specialised in the argument from the fine-tuning of the universe for intelligent life. So that gives Craig his backup for his third argument.

Carroll has two philosophers in tow. Alex Rosenberg is a philosopher at Duke University who Craig has debated before, and whose book “The Atheist’s Guide to Reality” was praised by both sides of the debate as seeing rather clearly the consequences of atheism. Tim Maudlin is a philosopher of science at New York University. His book “Philosophy of Physics: Space and Time” is marvellous. He also seems to have taken an interest in the fine-tuning of the universe for intelligent life. (I have a few reservations about his opinions on that topic.)

That’s an interesting line up. I’d gladly hear any of them speak on the topic at hand; all four of them in a row with responses from Carroll and Craig is very promising.

My advice

I think this debate could be uniquely insightful on this important topic. Craig has said an awful lot about cosmology in recent years, and no one has really pressed him on the details. They’ve mostly (though not unreasonably) appealed to cosmological authorities. (For the love of Pete, nobody read out an email from Alex Vilenkin. More on that soon.) Carroll has said a lot about the implications of cosmology for theism, and there are some philosophical niceties to be examined there as well. Stay tuned for parts two, three, and four.

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