Monday, May 09, 2016

Book review: “The Big Picture” by Sean Carroll

The Big Picture: On the Origins of Life, Meaning, and the Universe Itself
Sean Carroll
Dutton (May 10, 2016)

Among the scientific disciplines, physics is unique: Concerned with the most fundamental entities, its laws must be respected in all other areas of science. While there are many emergent laws which are interesting in their own right – from neurobiology to sociology – there is no doubt they all have to be compatible with energy conservation. And the second law of thermodynamics. And quantum mechanics. And the standard model better be consistent with whatever you think are the neurological processes that make you “you.” There’s no avoiding physics.

In his new book, The Big Picture Sean explains just why you can’t ignore physics when you talk about extrasensory perception, consciousness, god, afterlife, free will, or morals. In the first part, Sean lays out what, to our best current knowledge, the fundamental laws of nature are, and what their relevance is for all other emergent laws. In the later parts he then goes through the consequences that follow from this.

On the way from quantum field theory to morals, he covers what science has to say about complexity, the arrow of time, and the origin of life. (If you attended the 2011 FQXi conference, parts will sound very familiar.) Then, towards the end of the book, he derives advice from his physics-based philosophy – which he calls “poetic naturalism” – for finding “meaning” in life and finding a “good” way to organize our living together (scare quotes because these words might not mean what you think they mean). His arguments rely heavily on Bayesian reasoning, so you better be prepared to update your belief system while reading.

The Big Picture is, above everything, a courageous book – and an overdue one. I have had many arguments about exactly the issues that Sean addresses in his book – from “qualia” to “downwards causation” – but I neither have the patience nor the interest to talk people out of their cherished delusions. I’m an atheist primarily because I think religion would be wasting my time, time that I’d rather spend on something more insightful. Trying to convince people that their beliefs are inconsistent would also be wasting my time, hence I don’t. But if I did, I almost certainly wouldn’t be able to remain as infallibly polite as Sean.

So, I am super happy about this book. Because now, whenever someone brings up Mary The Confused Color Scientist who can’t tell sensory perception from knowledge about that perception, I’ll just – politely – tell them to read Sean’s book. The best thing I learned from The Big Picture is that apparently Franck Jackson, the philosopher who came up with The Color Scientist, eventually conceded himself that the argument was wrong. The world of philosophy indeed sometimes moves! Time then, to stop talking about qualia.

I really wish I had found something to disagree with in Sean’s book, but the only quibble I have (you won’t be surprised to hear) is that I think what Sean-The-Compatibilist calls “free will” doesn’t deserve being called “free will.” Using the adjective “free” strongly suggests an independence from the underlying microscopic laws, and hence a case of “strong emergence” – which is an idea that should go into the same bin as qualia. I also agree with Sean however that fighting about the use of words is moot.

(The other thing I’m happy about is that, leaving aside the standard model and general relativity, Sean’s book has almost zero overlap with the book I’m writing. *wipes_sweat_off_forehead*. Could you all please stop writing books until I’m done, it makes me nervous.)

In any case, it shouldn’t come as a surprise that I agree so wholeheartedly with Sean because I think everybody who open-mindedly looks at the evidence – ie all we currently know about the laws of nature – must come to the same conclusions. The main obstacle in conveying this message is that most people without training in particle physics don’t understand effective field theory, and consequently don’t see what this implies for the emergence of higher level laws. Sean does a great job overcoming this obstacle.

I wish I could make myself believe that after the publication of Sean’s book I’ll never again have to endure someone insisting there must be something about their experience that can’t be described by a handful of elementary particles. But I’m not very good at making myself believe in exceedingly unlikely scenarios, whether that’s the existence of an omniscient god or the ability of humans to agree on how unlikely this existence is. At the very least however, The Big Picture should make clear that physicists aren’t just arrogant when they say their work reveals insights that reach far beyond the boundaries of their discipline. Physics indeed has an exceptional status among the sciences.

[Disclaimer: Free review copy.]

77 comments:

Mitchell said...

I can guarantee that whatever Sean Carroll's answer to the problem of qualia is, it's nonsense. Subjectively perceived colors, to take one screamingly obvious example, are a part of reality, and they are not part of any conventional physical ontology.

Sabine Hossenfelder said...

Mitchell,

May I politely ask you to please read the book and stop wasting my time?

gowers said...

Thanks for that information that even Jackson doesn't believe the Mary argument. I've always been amazed at how seriously it has been taken (as well as other muddled arguments in a somewhat similar spirit like the Chinese Room argument or the zombies argument).

Sabine Hossenfelder said...

Sean also takes care of the Chinese Room and the zombies :o)

Uncle Al said...

Physics is applied mathematics, a science. Rigorous derivation from a non-empirical postulate can real world fail. Fundamentally mirror symmetric reality excludes baryogenesis. Falsification is opposite shoes vacuum free falling as a footnote in Einstein's elevators. Look.

"second law of thermodynamics" Empirical falsification: A hermetically isolated (adiabatic) hard vacuum envelope contains two closely spaced but not touching, in-register and parallel, electrically conductive plates having micro-spiked inner surfaces. They are connected with a wire, optionally containing an in-series dissipative load (small motor). One plate has a large vacuum work function material inner surface (e.g., osmium at 5.93 eV). The other plate has a small vacuum work function material inner surface (e.g., n-doped diamond "carbon nitride" at 0.1 eV). Above 0 kelvin, spontaneous cold cathode emission runs the closed isolated system. Emitted electrons continuously fall down the 5.8 volt potential gradient. Electron evaporation from carbon nitride cools that plate. Accelerated collision onto osmium warms that plate. Round and round. The plates never come into thermal equilibrium when electrically shorted. The motor runs forever.

Like SUSY and non-classical gravitation, the foregoing does not perform. Find the error.

Carey said...

Sabine,
I enjoy your writing, and am looking forward to your book as eagerly as I have anticipated Sean's.

Andrew Thomas said...

I dob't think the Chinese room is a "muddled argument". I think it's very interesting, I've always felt it gives the best insight on intelligence and consciousness. I'd be interested to see what Sean Carroll makes of it.

Andrew Thomas said...

Basically, is a computer which simulates intelligence, and passes the Turing test, actually conscious? Surely not. I hope that's Carroll's conclusion as well!

Simulation isn't enough, there must be some internal mapping to real-world objects, eventually resulting in self-awareness. That's my take on it. That's my take on the Chinese room.

Aaron Ginn said...

What the hell are you blathering about, Uncle Al? Go build your perpetual motion machine and make a fortune. Then you can come back and demonstrate you know what you're talking about rather than stringing a bunch of words together.

Mensan my ass.

Quentin Ruyant said...

I'm sure Carroll's philosophical arguments are sound and interesting. But I'm also pretty sure not all philosophically informed physicists, nor all physically informed philosophers agree with him, and calling all this bare "implications of physics" rather than one possible position on the market is just... well... not being very well philosophically informed. Sorry to say this. Why do scientists so often have this bad habit of taking their pet philosophical theory as the only game in town, and get so mad against contradictory views, seriously?

Jonathan Miller said...

I haven't read this book and I intend to. Thanks for the review.

But I have a question for you, and it is based on posts on this blog as well as many other places (particularly comics at SMBC). What is the difference between our reality being simulated and our reality being deistic or even theistic?

It seems to me that our reality being simulated is ontologically the same as our reality having some sort of god/gods or 'supernatural'. There are even interpretations of Christianity that are equivalent to a simulation hypothesis.

Is it just that I read too much SF?

Jim said...

Peter Woit has a few disagreements with Carroll's exuberance that are well worth reading (http://www.math.columbia.edu/~woit/wordpress/); I'll only repeat one well-stated point here: "... I just don’t think theoretical physicists have anything useful to tell the average person about meaning and morality, other than that it’s a mistake to search for it in our discoveries about physics."

Kaleberg said...

It sounds like a good book, but a bit too philosophical for me. The only philosophy I read is at:

http://existentialcomics.com/

Of course, there are obvious reasons that physics bumps up against philosophy now and then. Then again, chemistry and biology bump up against philosophy as well, especially what they now call brain science.

Sabine Hossenfelder said...

Jim,

Well, if you mean that theoretical physics doesn't have anything to say about meaning and morals, then that's pretty much what Sean (needless to say) also explains. Whether theoretical physicists have something to say about it is an entirely different question...

Sabine Hossenfelder said...

Quentin,

Of course not everybody agrees on everything - when is this ever the case. But there are clearly some "ideas" that should be put to rest, like the possibility of ESP by some still undiscovered force or "downwards causation" which is just plainly incompatible with what we know about the laws of nature. And "qualia" is really just a misunderstanding about how to brain works. Look, this isn't 1885 any more. Science has made progress. Philosophy should catch up to this. Best,

B.

BG said...

Bee,

you say: "Whether theoretical physicists have something to say about it [meaning and morals] is an entirely different question...".

What do you mean exacty? Perhaps that theoretical physisics are more autoritative than other people when they speak about meaning and morals?

Sabine Hossenfelder said...

BG,

I meant exactly what I wrote: whether theoretical physics has something to say about meaning and morals is a different question than whether theoretical physicists have something to say about it. You shouldn't confuse a practice with its practitioners.

I don't know why Sean wrote the book, so let me instead tell you something about my experience. What theoretical physics says about the meaning of life and morals is, to make a long story short, nothing. Now if I go about and tell people there isn't fundamentally anything more to the universe than theoretical physics, there's no god, no good and no bad, and if you're dead you're dead, this sounds pretty depressing. Who then to turn to for guidance? The most common reaction I get to my writing about free will (leaving aside hostile deniers) is confusion. People who haven't grown into thinking about nature by means of a Hamiltonian evolution simply don't know what to make out of this.

I actually wrote about this several times - it's a hole that science leaves and that I'm afraid makes many people cling to religion. Not so much because they think religion is great, but because science simply doesn't say anything about what to do if you leave behind religion. It's a hole that scientists should fill, and that's basically what Sean does in his book.

Now look, it's not like I want to tell you to preach the gospel of Sean, and I think there are some important things he hasn't addressed (maybe I'll get to this some other time). But either way, he simply demonstrates that religion is unnecessary, and whether or not you like his "Ten Considerations" that's a good thing to do. Best,

B.

BG said...

Bee, sorry but there is still something not clear to me.

When you write: "What theoretical physics says about the meaning of life and morals is, to make a long story short, nothing", do you mean:

1) theoretical physics doesn't have anything to say about meaning and morals, so that anybody may find his meaning and his morals with other cognitive tools different from theoretical physics.

2) Theoretical physics says that "there isn't fundamentally anything more to the universe than theoretical physics, there's no god, no good and no bad" (your sentence).

Of course these two positions are very different. I am in favour of 1, because I believe that theoretical physics (or more in general science) is not the only cognitive tool we have for knowing and understanding reality.

Plato Hagel said...

Sean explains consciousness?

Sabine Hossenfelder said...

BR,

Physics isn't a "cognitive tool". Physics merely gives you some constraints about what you can or can't expect from other disciplines. It tells you for example that meaning isn't fundamental but emergent, it is hence something we make ourselves and not something we can derive. Not with religion and not with meditation and not with philosophy. You can't derive it, you have to make it yourself.

Let me put one thing ahead. Physics has something to say about morals in the following sense: morals are simplified thought patterns that we use to make quick decisions. These come about by the laws of nature like everything else. This doesn't tell us however what it is that we "should" be doing. It merely says that the laws of nature determine what it is that we think we should be doing.

You give me a choice between 1) and 2) but neither captures my position, and that you grab 2) out of context distorts what I meant to explain in this paragraph, which was that even though there isn't *fundamentally* anything else, doesn't mean there isn't anything else.

To sum up. I'm far less radical than you seem to believe. I am merely saying that whatever "cognitive tool" (I'm not sure what this is supposed to be) you want to use, it has to be consistent with what we know about the universe. And that's for example that praying doesn't cure cancer and nobody has ever seen a miracle happen and you can't push around things by power of your thought and so on. It also means that your brain is a collection of a lot of particles and forces and nothing else, and whatever laws emerge from this, they have to be consistent with the lower-level laws.

Best,

B.

Sabine Hossenfelder said...

Plato,

No, of course not. He merely explains that regardless of how we will one day define consciousness, its existence is perfectly compatible with the standard model and we don't need to change the fundamental laws of nature to accommodate consciousness. You'd think that's pretty obvious, but apparently it's not.

Plato Hagel said...

It's possible that contextuality in regards to what one believes, given you have this big picture, is a better understanding of quantum cognition as it is used?

Plato Hagel said...

I like to think there are deeper connections regarding consciousness that have not been explained and are difficult to do so, and of course here I think of Tegmark's preponderance..... http://youtu.be/MjhEtqhUZkY

Sabine Hossenfelder said...

For all I know it's possible, but it seems rather unlikely. Quantum effects are fragile, and while they are known to play a role in some chemical reactions, it doesn't seem very plausible they'd be very relevant for consciousness because you'd expect that to be very unstable. But just what their role is, if any, will remain unclear as long as we can't define "consciousness".

BG said...

Bee,

I think our disagreement is about reductionism vs. emergence. Very synthetically:

1) Reductionism: there are some fundamental physical laws that explain the behavior of Nature at all its level (life, human behavior, etc).

2) Emergence: the behavior of Nature at the higher levels is compatible with the laws at the lower levels, but it cannot be explained by them. New laws emerge which cannot be derived from the lower levels laws.

From what you write I guess you believe in 1 (sorry if I am still misunderstanding you), while I believe in 2. In the case, 1 is a legitimate belief, but it is a belief, it is not Physics, because nobody has explicitly derived e.g. the human behavior from the equations of the standard model.

Let me quote a sentence of Kip Thorne from the book of Gefter "Trespassing on Einstein's Lawn", with which I totally agree:

"As physicists, we have been tremendously successful at building pictures and mathematics that are very predictive, but we have never developed any set of tools or criteria to tell us what is ultimate reality. I think we are less in the position to probe those issues than philosophers are. But the only philosophers who have a prayer of making progress are those that understand the physics. I steer clear of asking what is ultimate reality".

Sabine Hossenfelder said...

BR,

Emergence is compatible with reductionism, I think you mean to distinguish between weak emergence (higher level laws can be derived, it is compatible with physics) and strong emergence (they can't be derived, incompatible with physics). And as I said in my blogpost, strong emergence is plainly in disagreement with what we know about the laws of nature, hence it doesn't deserve further discussion until evidence comes in to the contrary.

Incidentally your insistence that it is a "belief" because higher level laws have not been derived is exactly what I mean when I say people don't understand that because they don't know what effective field theory is. You do not actually have to derive the higher level laws to know that they follow from the lower level laws - there can only be one correct law, and we already know where it comes from. May I hence politely ask you to please read Sean's book?

Uncle Al said...

@Aaron Ginn: "...the foregoing does not perform. Find the error." It is valid until you disclose the error in reasoning, re OPERA superluminal muon neutrinos being a poorly connected fiberoptic timing link. Post the one word that fails to falsify the Second Law.

The difference between two vacuum work functions is arithmetic. Why is there no electric field potential between the connected plates? Sean Carroll describes contingencies of theory requiring curve fittings. This is suspect.

JimV said...

I define consciousness as an operating system, analogous to Windows, which receives external inputs and transmits them to internal, unmonitored programs for processing, and receives feedback from these internal systems which cause it to produce external outputs. That is, from Windows' point of view, it transmits keyboard input to, say, the Excel program. Excel does its magic and sends back a number which Windows then displays on a screen. Windows does not know what Excel is doing or how it does it, which could add an air of mystery to a mundane process.

As to what this "feels" like, to a brain or to a computer, who cares? Why does a rose smell like a rose? That is, why does the chemical process of scent, which could be duplicated by electronic machinery, "feel" as it does? Well, if it didn't feel like anything, it wouldn't work and wouldn't have evolved.

We don't understand the detailed workings of a brain with over 70 billion neurons as well as we understand Windows or the scent process, and maybe never will. Other that, I myself don't understand why some people think there is a (meaningful) problem with consciousness.

Thanks for the review. I like to give my semi-fundamentalist nephews and nieces science books as graduation presents (along with some money as bookmarks, in an envelope attached to the inside of the back cover). Dr. Carroll's book will arrive in time for another niece's high school graduation, but I think I will have to use "Trespassing On Einstein's Lawn" instead, because I think fundamentalists will find TBP offensive - as some previous comments suggest. Based on my own applications of the laws of physics, I am impelled to make another donation here for the useful information.

Don Foster said...

Bee,

“… I’ll never again have to endure someone insisting there must be something about their experience that can’t be described by a handful of elementary particles.”

This is an exasperatingly strong statement. From my provincial point of view, the physical theory upon which you base it has a firm grasp on some portion of the elephant, but does not fully characterize the nature of the beast.

Let’s come at it from the notion of physical trajectories. In a nutshell, that is where physics began and where it excels. Given one set of conditions there are equations that will accurately trace the arc of their dynamic evolution. The consequence of emergence is that the fundamental laws of physics are not the most complete description of all dynamic trajectories.

For example, consider the path of a 50kg mass as it moves through an enclosure 330 cubic meters in extent. Translate that general physical description into the actual event of you standing at one side of a crowded room, wine glass in hand, and making your way to the other side. Is your path completely determined by the fundamental laws of physics?

There are physical dynamics that are not fully prescribed by a handful of elementary particles.

Regards,

Braden! said...

Hi Bee!

If you're willing to entertain another question about strong emergence: I was wondering if you have read or heard about the papers "More really is different" by Gu et al (http://www.sciencedirect.com/science/article/pii/S0167278909000852 , http://arxiv.org/pdf/0809.0151v1.pdf ) and "Undecidability of the spectral gap" by Cubitt, Perez-Garcia & Wolf (http://www.nature.com/nature/journal/v528/n7581/full/nature16059.html , https://arxiv.org/pdf/1502.04573.pdf )?

The papers build microscopic models from which you cannot predict all macroscopic quantities even with knowledge of all the microscopic interactions. (Basically by mapping undecidable computational models onto an equivalent physical Hamiltonian). To quote the abstract of the second paper, "Our result implies that there exists no algorithm to determine whether an arbitrary model is gapped or gapless, and that there exist models for which the presence or absence of a spectral gap is independent of the axioms of mathematics."

These results have been interpreted as examples of strong emergence in physical models (albeit in the thermodynamic limit). Provided Sean hasn't already addressed these papers (or related) in his book, I was curious as to how you would interpret these results? Strong emergence? Strong emergence in potentially physically unrealizable systems? Something else altogether?

Sabine Hossenfelder said...

Braden,

I wrote about the first paper here, the newer one I haven't had time to look into, sorry.

Sabine Hossenfelder said...

PS: Strong emergence, yes, but in a physically unrealizable system. I could add another example to this list, but I don't have a paper written up.

Quentin Ruyant said...

Don't think philosopers are scientifically illiterate: many of them (in phil of sci particularly) were scientists before, or at least have a scientific degree. Downward causation and qualia are only incompatible with your metaphysics (reductionist, scientific-realist and physicalist I guess--I'm fine with that, but it's nothing "physics tells us").

Sabine Hossenfelder said...

Quentin,

You're wrong, downwards causation is plainly incompatible with laws for whose correctness we have extremely strong evidence. (Or else you mean something different with downwards causation than I do. Every once in a while I encounter people who use it to mean something else than strong emergence.) If you don't understand what I am referring to, please read Sean's book.

Quentin Ruyant said...

First, causation is not a term of the art in physics, it is more a philosophical or common sense term, and it is notoriously difficult to define precisely. There are many theories of causation (counterfactual/probabilistic, transmission of physical magnitudes, interventionist theories, or even eliminativism: causation as just a way of talking...) and all have problems to solve. Second, laws of physics exclude downward causation only if you assume the causal completude of physics (every event has a sufficient physical cause) and the supervenience of higher level properties on physical properties (no higher level difference without a physical difference). It might be reasonable, and many think these are good principles, but it does not go without saying. There's also the question of type or token supervenience (type : being a gene is nothing but being such or such kind of molecule, token : this particular gene is nothing but a molecule of this kind). Type supervenience is more problematic. There's no convincing reductive account of biological, or even certain chemical types to physics. What makes a molecule a gene depends on a cellular environment and the complex functional network associated with it for example. The same molecule can be our not be a gene depending on the context. But biologists and chemists talk in causal terms much more than physicists do, and usually it's causation between types. What I mean is that it's not so easy to make sense of all these concepts to get a coherent picture, even though (as almost everyone agrees) the laws of physics constrain every material entities. Not to mention that all these questions apply within scientific realism: the (common sense) assumption that our scientific representations directly correspond to reality... Which can also be challenged. I didn't read Carroll so I don't know if he addresses all these questions, but I'm confident that if he does, he is doing philosophy, not pure physics.

Maurice said...

Sabine,
may I bring forward a respectful criticism of your book review? On the one hand you do not really discuss the central new material of Sean's book: his discussion of meaning and morality. Is this part a worthwhile read? Is Sean qualified to write about it? A good review must tell the reader. It's what she really needs to know in order to decide whether to order the book. On the other hand your review contains way too much material unrelated to Sean's book. You talk about your book, what you're not good at, what you think everybody should conclude etc. I estimate this stuff takes up about 30% of your review! Also the relation of your intro to Sean's book remains unclear.

Sabine Hossenfelder said...

Quentin,

We're talking past each other. Your elaboration on causation is entirely irrelevant to the point. I do not "assume" that higher level laws follow from the lower level laws, I am telling you that we know this based on observations that have led us to the standard model and general relativity. This isn't philosophy, it's science. The higher level laws follow from the "reductionist" underlying laws by means of effective field theory and any other higher level laws are hence inconsistent with established science. Your belief that it can be different is plainly inconsistent, either internally or with observation.

Give me one single example in which you can demonstrate that a higher-level law does not follow from the fundamental law (standard model and gravity) and is nevertheless consistent with that law. Think about this for a moment and you will realize that it's not possible: There is already a law for this system, we know that. Like it or not, large stuff is made out of smaller stuff. Whatever other higher law you want to come up with, it has to be compatible with the "reductionist" law.

Please read Sean's book. You are missing essential points about the relation of laws on different levels.

Sabine Hossenfelder said...

Maurice,

I've said this a few times before, but I suppose it can't be repeated sufficiently often. This is my blog, I write what I like, and I write how I like. So thank you for the respectful criticism which I will respectfully disregard.

Let me also mention that on the occasions that I did write reviews for this or that magazine they explicitly asked me to bring in my own opinion rather than write "the author said so and then so and then so". If you're not interested in my opinion - too bad then, and good-bye.

Personally I find the chapter on moral and meaning entirely superfluous because, as I wrote, I think everybody should come to this conclusion by themselves. On the other hand, I know that it evidently isn't the case as I see from comments on this blog. So I think the chapters belong there for completeness. These are important topics that people care about.

I wouldn't say though that these are the "central" parts of the book. They are just (not so suprisingly) the parts that everyone seems to get hung up on.

Maurice said...

Of course you should voice your personal opinion about the book in a good review! But your opinion about other issues does not belong there. Do I interpret the unfriendly, irritated tone of your reply correctly: you do not welcome criticism in the comments even when it is respectful and to the point of your posts?

Quentin Ruyant said...

It's not obvious that there are biological "laws", or any higher level, universal laws in the sense of the physicist. Which doesn't mean that there's no causal relations at higher levels! You might see this as quibbling over definitions (of causality for ex), but I don't think definitions are a mere problem of linguistic conventions, as if we could ideally talk in physical models only. I think our higher level language aims at capturing important aspects of the world we live in. Your stance seem to be that everything that is not physics is mere "talk", but is mostly irrelevant to how the world really is: all that is relevant is the universal laws that we managed to discover and confirm through experiments at the microscopic level by performing highly controlled interventions on bounded systems. Now the behaviour of a simple molecule is not even computable from physics alone, without adding contextual assumptions, higher level "effective" observations and approximations, so the idea that these laws exhaust what there's to say about the world is a very idealistic view (and I'm not talking about more complex entities). My point is only that there are informative facts about the world beyond physics, and that they can be expressed in causal terms, or that once you provide a "physical model of the universe" (if really there's such a thing) you've not exhausted everything there's to say about it. Even though the physical description is strictly true. This is a philosophical view, apparently you think it's wrong. We disagree. That's fine. You say that your view is "what physics says". Well, no, that's not what physics says.

Sabine Hossenfelder said...

Maurice,

Telling me what I'm supposed to write and not to write on my blog isn't criticism, it's your opinion.

Sabine Hossenfelder said...

Quentin,

No, you continue to misunderstand me. I have not said and would never say that everything that is not physics is mere "talk". I have deep respect for the other sciences. I even wrote explicitly in my review that they are important in their own right. Neither did I ever even remotely say that "all what is relevant is the universal laws" and so on. Please stop putting words into my mouth which I didn't use. I do find it offending that you project on me your beliefs about what physicists supposedly think like.

The behavior of a simple molecule is - in principle - very computable from physics alone. I don't know what you mean with "contextual assumptions".

I agree that a low-level physical model of the universe doesn't exhaust everything there's to say in the sense these models give rise to many emergent properties.

Quentin Ruyant said...

Ok sorry if I misinterpreted your views. In practice we must use simplified models to know the properties of molecules and usually they rest on knowledge from chemical experiments and observations, not physics alone. "In principle"? Perhaps (I understand it seems reasonable to think so). It is hard to defend downward causation and many philosophers agree with you, but I'm not convinced it's impossible and still think it's a rather metaphysical question. It's quite intuitive to think that my desires can cause my bodily movements and I think this kind of intuitions must not be dismissed from abstract considerations. At least we should account for them and it's not an easy task. I'll have to read Carroll's take on this. Anyway thank you for the discussion.

Noa Drake said...

Hello Sabine,

'Physics has an exceptional status among the sciences' is your remark at the end of the review.

This reminds me of an interview with R. Feynman where he comments that most other sciences are not really science because they are not 'exact'.
But then just how exact has modern physics become when it is intrinsically composed of a modus operandi that works with approximations, infinities and probabilities ? And isn't the lacking part precisely the as yet unknown exactness physicists hopes to find with quantum gravity theories ?
If physicists would be more prepared to get to know and incorporate the know-how of the other sciences, then that would enrich the foundations of their thinking and augment the quality of future theories. Pyramids of Egypt are more durable than towers of Pisa, and require less adjustments and reinforcements to keep them standing in the long run.
On many occasions I have agreed with you, but not on your conclusion in this post. But woulndn't it be boring if there was no room for debate ? Isn't that the engine of progress ?

Greetings, Noa

piein skee said...

"Telling me what I'm supposed to write and not to write on my blog isn't criticism, it's your opinion."

The thing is you run this blog as a de facto public outreach portal with a mission, presumably, consistent with the vision of the 'scientific citizen' for a better tomorrow.

A lot of people that come here will take what you say as gospel. Typically they also show up with inappropriate feelings of deference and gratefulness - that is wholly antithesis to attainment of that 'scientific citizen'.

That bestows on you a moral responsibility delineate very clearly between what is scientific consensus, what is controversial (which is not something that gets settled between you and your network of sympathetic like-minded associates), and what is entirely your own unqualified opinion.

The truth is you get away with not doing that for now, because is no formal scrutiny of this kind of blog. But just because you can get with it, does not mean that you should.

Sabine Hossenfelder said...

piein,

Indeed, that's what I am doing: The scientific consensus is that strong emergence doesn't exist. If you don't believe that, find me someone who understands effective field theory and who believes in strong emergence. Where's your "moral responsibility" when it comes to people who confuse others by producing a lot of ill-informed fog driven by a misunderstanding about what we've learned about the fundamental structure of laws? Hasn't religion and moral fundamentalism done enough harm to mankind?

Tobias Kosub said...

Isnt it worthless to fight over people's believes regarding theism, free will, conciousness etc. when nobody has "free" choice to change their opinion about it ?

Without choices, why do we bother to discuss or do anything at all? Thats why I want to believe in what Im doing and thinking is deliberate, although I see no physical reason for this imagination to be justified. ;)

piein skee said...

Hi Dr Hossenfelder - I was joining the you/Maurice discussion not the emergence. You were saying you'd do whatever you liked on your own blog.

If you're saying that you aspire to those sort of standards, then we don't have that much to argue about, which is a good thing.

The problem is widespread on science blogs not just you or here, of science bloggers reinforcing layperson newcomers sense of deference/gratefulness in various ways. The driver is that having the ego fed is pleasurable, and also that it's easier and lazier.

But those laypeople will emulate not just the facts that they takeaway but the way the facts are delivered and the way curiousity and naieve-creativity is handled as well as any implicit attitude toward that sort of thing.

It doesn't take much to become the local authority on your street or down your local bar. To be a guru, you only need to know a tiny bit more than others around. It's just worth keeping this mind, because when you in a position of trust, it's what you are being like that is emulated and spreads, and not what you are saying that you are like.

You're mostly fine by way. This is a narrow matter.

Phillip Helbig said...

"Isnt it worthless to fight over people's believes regarding theism, free will, conciousness etc. when nobody has "free" choice to change their opinion about it ?"

It depends on at which level you look at it. The same remark could reply to your comment. But, of course, you couldn't help yourself. :-) Similarly, even if it is worthless, there is no way to choose not to fight. :-|

At a different level, there is a misunderstanding. The lack of free will doesn't mean that a person will do something no matter what. Rather, it means that, given a certain environment, a person has no choice but to do something. This is why the question of free will is irrelevant for crime and punishment. In civilized law codes, vengeance doesn't play a role. Punishment is to protect society from dangerous criminals, to provide a deterrent, and to encourage reform on the part of the criminal. None of these goals change depending on whether or not free will exists.

Similarly, of course one can debate such topics. The lack of free will does not mean that one must believe the same things forever. People do change their minds. They might not have a choice, but that is irrelevant to the worth of a goal.

Charlie said...

Thanks for the review Sabine! I'm sure I'll get to this book sometime. I really enjoy the outreach that you and Sean and others provide. I'm a research biologist so I get to take all of this fundamental stuff for granted, but I feel like I'm learning something about the way theoretical physicists go about their work.

Can't resist a dead horse though. I was inspired to look up definitions of "free will" in various places and they are usually something of the form: "the ability to decide or take action not determined by _______". It has meaning or no meaning depending on what you put in that blank. E.g., "I resigned my tenured position of my own free will," the blank being something implied and possibly ominous. I think even theologians use it sometimes (depending on the particular discussion at hand) with God inserted in that blank. In my behavioral genetics class, students invoke "free will" when they are upset at the idea of "genetic determinism." (That notion entails implausibly high estimates of heritability, or that allelic effects are large compared to environment, epigenetics, gene x environment interactions, etc.) I do, of course, make choices every day. It is silly (given what we know now) to think I can make those choices free from my own neurons or from the influence of those around me.

Probably I should be more of a hard-ass, but I tend to go with "depends on what you mean..."

Arun said...

So, Bee, does mathematics have any existence outside of our physicality?
That is, can a physicalist also be a mathematical platonist?

piein skee said...

" The lack of free will does not mean that one must believe the same things forever. People do change their minds."

I don't think humans do change their minds - not the insights & theories that matter, come hard won, years in the making. It might not even be possible.

The reason we don't perceive that this is the case, is because the vast majority of issues that come up, have little or no bearing on, or relevance to, that accumulated core belief.

We're all more than happy to change our mind on the things we don't care that much about. Everything changes everything stays the same .

piein skee said...

....with that said (about people not changing their minds), for your entertainment and for a 5 minute video that may leave you with a surprisingly large helping of....food for thought.....this guy does not use stooges or plants.. https://www.youtube.com/watch?v=W-i_9DOCsEY

Sophie said...

Than you so much for this book review. Just ordered the book from Amazon. Hope to see your own book too Sabine! :-)

Bert Morrien said...

Thanks for this review, I am eager to read the book. My idea about morality: the brain is about adjusting weights, it can balance its own happiness with that of others and a good balance is important for its own happiness. No miracles here.

piein skee said...

p.s. sabine on the off-chance you don't know, the 'recent comments' widget isn't working.

Sabine Hossenfelder said...

piein,

Thanks for letting me know, I hadn't noticed. The recent comments widget is a pain, it stops working every other year or so. I've put in a replacement, but that doesn't seem to update properly. Sorry about that. Will see if I can find a better solution.

Bert Morrien said...

Dr Hossenfelder,
You said "The behavior of a simple molecule is - in principle - very computable from physics alone."
I think I know what you mean, but isn't it true that when an individual atom absorbs a photon one cannot compute when it emits a photon. This atom behaves as if it is aware of its exitement, that it doesn't want this and that it gets rid of it as soon as possible.
I can't help to see this as evidence that matter expresses individual experience, just like a human being. If experience is a hard problem, then the behavior of a single atom is a hard problem too, don't you agree?
Of course, human experience is somewhat richer than that of a single atom.

Sabine Hossenfelder said...

Bert,

There are things that - to our best present knowledge - just can't be predicted, such as decay times, individual scattering outcomes and so on. This is irrelevant though for the point I was making, that being that the behavior of the molecule follows from the behavior of its constituents (to the extent that it is knowable at all).

Bert Morrien said...

Dr Hossenfelder,

Thanks for your answer. The constituents involved with spontaneous photon emissions are known to the extent that these allow calculation of mean values, but never individual ones. This is certainly not magic, but the point is that we cannot distinguish it from magic.

Sabine Hossenfelder said...

Bert,

If you want to call quantum mechanics "magic," then please go ahead. As I said, I'll not fight about words.

Bert Morrien said...

Dr Hossenfelder,

Thank you again. You are right, it's quantum mechanics. David Chalmers should know better.

Don Foster said...

Bee,

Thank you for the engaging post.

Just to be clear on your proposition regarding the existence of free will, please correct my restatement of it as necessary:

Free will does not exist because established physical theory indicates that the time evolution of some earlier state of the universe determines all dynamic events of the present moment.

Then, if that is sufficiently accurate, there is further question. What point in time do we select as the initial state?

Best,

Sabine Hossenfelder said...

Don,

The time evolution of some earlier state determines the present state, up to outcomes which are fundamentally unpredictable (if you believe in qm collapse), which can't be influenced by anything and in particularly not by you. Hence, no combination of a deterministic evolution with a non-deterministic ingredient has space for anything like free will.

You can pick any time as initial state, you can pick the present state or even a future state. This is why I've said (in one of my papers I believe) you could as well say the present is determined by the future, it's just that we don't think this way (arrow of time and all). Or, more compatibilistically, you can say that the future is determined by the present. The whole point is that (leaving aside some fineprint about the global structure of space-time) all moments are in a one-to-one correspondence.

Bert Morrien said...

FYI: Experimental test of the free will theorem.
"The conclusion of the free will theorem is that elementary particles have free will in the sense that they produce results that are not a function of the past."
See next link.
http://arxiv.org/abs/1603.08254
(Again, it's all quantummechanics!)

Sabine Hossenfelder said...

That's not actually what the "free will theorem" states. It states (in a nutshell) "if the experimentalist has free will then so must elementary particles have free will." The reasonable conclusion to draw from this is that since elementary particles don't have free will, neither has the experimentalist. (Which is what I've been telling you all the time.) Either way, the so-called theorem doesn't prove either one or the other, merely a relation between two statements.

Bert Morrien said...

Dr Hossenfelder,

I think you are absolutely right. You made me think twice. You cannot make a distinction between elementary particles with or without free will. You cannot say that they posses free will, but you cannot say that they don't either. I see now that free will is not a subject for a scientific discussion, because you cannot measure it. You can definitely measure something, but not free will.

Don Foster said...

Bee,

“The import of the free will theorem is that it is not
only current quantum theory, but the world itself
that is non-deterministic, so that no future theory
can return us to a clockwork universe.”

--The Strong Free Will Theorem
John H. Conway and Simon Kochen, 2009

One can find all sorts of things on the Web including the views of John Conway. Unfortunately, though a Google search for “experimental proof of strong determinism” returns more than 28 million results in 28 seconds, there is not much clarity to be found there. The Stanford Encyclopedia of Philosophy’s article on “Causal Determinism” (substantive revision Thu Jan 21, 2016) was the most thorough reference and its section on the “Status of Determinism in Physical Theories was not hopeful:

“Figuring out whether well-established theories are deterministic or not (or to what extent, if they fall only a bit short) does not do much to help us know whether our world is really governed by deterministic laws; all our current best theories, including General Relativity and the Standard Model of particle physics, are too flawed and ill-understood to be mistaken for anything close to a Final Theory.”

You have made a clear statment regarding determinism and it would be helpful to know what part of the Standard Model, Effective Field Theory, General Relativity or experimental result led you to that conclusion.

I observe that recursive dynamics partition causality into causal domains, that the time evolution of path would be more accurately described as an interaction between these domains. That said, I would like to sort out what seem to be to be an important rational stance on the nature of the universe.

Thanks,

Marc H. Abrams said...

I finished Sean Carroll's book yesterday and greatly enjoyed it. I'm not a physicist, just an interested bystander atheist/naturalist. The human race is looking for answers to hard questions. A lot of what Sean says makes sense to me. Some of it I didn't understand. The reason I'm posting here is to make two comments:

1 - I don't know if Sean is right about everything (that would be quite a feat), but as long as his answers don't include, "God did it," I'm good.

2 - I like what Sean says about the Big Bang. It's not necessarily the beginning of space/time but only the point that we can look back to (I'm loosely paraphrasing here). Anyhow, these are my thoughts on space/time (again, I am not a physicist, just some guy): I don't think there was ever true nothingness. I don't think that is possible. The natural state of things is that there always be something, even it it's empty space, which I have read is not always stable (isn't that what Lawrence Krauss says?). Both Krauss and Carroll stated in their books that one day all the planets will be gone, the stars, the black holes. There will be nothing but empty space... for eternity. But empty space is unstable. Stuff happens. There is still some kind of energy. So what's to prevent another Big Bang? And can't that be what happened during the last Big Bang. Everything from the previous universe, whatever existed, I will assume stars and planets, etc, ran their course until there was nothingness, and then our Big Bang happened. Is this feasible? It's just a thought I have. Is it a possibility or does our knowledge of science absolutely rule it out?

Thanks for your time.

Sabine Hossenfelder said...

Marc,

The brief answer to your question is no, and the reason is that since the big bang entropy increased. It's not going to decrease, hence you can't repeat the feat. The longer answer is to read Sean Carroll's older book. Best,

B.

Marc H. Abrams said...

Thanks for your response. With no planets, stars, black holes, etc., I imagined there would be some kind of reset. Science says no.

Sabine Hossenfelder said...

Marc,

It is an idea that both Carroll and Penrose (for all I know) are advocating - I'm just saying you have to add something to the known physics to make it work, hence it's very speculative.

Lorenz Mayer said...

I am on the strong emergence site as well, but i fear this might be really a belief. Even when one looks within physics, there are some things which to my knowledge are not well understood. A very famous example os the emergence of classical mechanics from quantum mechanics; additionally i could think of the passage from mechanics to statistical mechanics.

Jim said...

@Lorenz
I think Carroll makes a very strong case that statistical mechanics does not involve strong emergence because its results can be deduced, in theory, from the position and velocity of the underlying particles. Much of the point of his book is the idea that emergence is mostly, if not completely, a matter of applying ideas in their natural and proper domain. It's not that statisical mechanics can't be described in terms of classical mechanics; it's just not useful to do it.

CGT said...

Hi,
Gambini and Pullin have a paper out recently arguing for strong emergence in quantum mechanics. It is here:
http://lanl.arxiv.org/abs/1605.07531 ("Event ontology in quantum mechanics and downward causation")

There is no discussion of effective field theory, renormalization group, etc. here, but there is a critique of using concepts from classical physics to decide the case against strong emergence, if I understood their paper correctly...

Soothsayer said...

Keep open-minded and stick to the facts, measurable knowledge. Learn to recognise speculation for what it is, and be skeptical to anyone that claims to own the truth, or that the world is only a few thosand years old. Science offers the best explanation for most things and is honest because when a better explanation comes along to explain what has been observed, the old theory, speculation, is put aside. Science is an objective attempt to get at the truth, not an attempt to defend truths and conclusions arrived at out of ignorance. It is in fact impossible for god to exist, no being can encompass infinity because infinity can not be encompassed. All mighty all powerful all knowing is such an infantile concept. A truth cannot be eternal, except the truth, the fact, that the physical universe in its entirety exists. There is no meaning to life other than the meaning that we ourselves give to it. I do not really believe anything but I find factual knowledge and human activity fascinating and sometimes meaningful.

Terrence Zellers said...


Color qualia are indeed reducble to physical. My take.

Andy Clark has proven to my satisfaction that qualia are *modalities* and their indexes within the brain as automaton. They certainly yield (and are) dispositional vectors but those too are rather easily in principle instantiable as mechanism in a complex system aggregate of simpler, ultimately basic physics elements.

-- TWZ