Monday, October 15, 2018

Dear Dr B: What do you actually live from?

Some weeks ago a friend emailed me to say he was shocked – shocked! – to hear I had lost my job. This sudden unemployment was news to me, but not as big a surprise as you may think. I was indeed unemployed for two months last year, not because I said rude things about other people’s theories, but simply because someone forgot to renew my contract. Or maybe I forgot to ask that it be renewed. Or both.

In any case, this happened a few times before, and while my younger self wouldn’t normally let such a brilliant opportunity for outrage go to waste, I now like to pretend that I am old and wise and breathe out bullshit.

After some breathing, I learned that this time my sudden unemployment originated not in a forgotten signature, but on Wikipedia. I missed the ensuing kerfuffle about my occupation, but later someone sent me a glorious photoshopped screenshot (see above) which shows me with a painted-on mustache and informs us that Sabine Hossenfelder is known for “a horrible blog on which she makes fun of other people’s theories.”

The truly horrible thing about this blog, however, is that I’m not making fun. String theorists are happily studying universes that don’t exist, particle physicists are busy inventing particles that no one ever measures, and theorists mass-produce “solutions” to the black hole information loss problem that no one will ever be able to test. All these people get paid well for their remarkable contributions to human knowledge. If that makes you laugh, it’s the absurdity of the situation, not my blog, that’s funny.

Be that as it may, I have given a lot of interviews in the past months and noticed people are somewhat confused about what I actually work on. I didn’t write about my current research in my book because inevitably the physicists I criticize would have complained I wrote the book merely to advertise my own work. So now they just complain that I wrote the book, period. Or they complain I’m a horrible person. Which is probably correct because, you see, all that bullshit I’ve been breathing out now sticks to them.

Horrible person that I am, I don’t even work in the foundations of physics any more. I now work on quantum simulations or, more specifically, on using weakly coupled condensed-matter-systems to obtain information about a different, strongly coupled condensed matter system.

The relation between the two systems stems from a combination of analogue gravity with the gauge-gravity duality. The neat thing about this is that – in contrast to either the gauge-gravity duality or analogue gravity alone – we are dealing with two systems that can (at least in principle) be prepared in the laboratory. It’s about the real world!

This opens the possibility to experimentally test the validity of the gauge-gravity duality, or its applicability to certain systems, respectively. Current experiments (like Jeff Steinhauer’s) aren’t precise enough to actually do this, but the technology in this area is rapidly improving, so I’m hopeful that maybe in a decade or so it’ll be doable.

If that was too much terminology, I’m developing new methods to describe how large numbers of atoms interact at very low temperature.

Today, Tobias Zingg and I have a new paper on the arXiv that sums up our recent results. And that’s what I’ll be working on until my contract runs out for real, in November next year. And then what? I don’t know, but stay tuned and we’ll find out.


Mars said...

Is it fair enough to state that:

a) any theory of Science beyond the Standard Model, should offer a convincing explanation for Dark Matter,
b) any unified theory of quantum gravity should offer a convincing explanation for Dark Energy?

papa said...

Dear Mrs B.
I would normally dismiss this as a "typo", but knowing your opinions on string theory and your sense of humour i am unsure;
"The AdS/CFT correspondence [1, 2, 3] relates certain conformal field theories (CFTs)
with quantum gravitational models that arise in sting theory."

Don Lincoln said...

What do you mean "particle physicists are busy inventing particles that no one ever measures?"

We may not find them, as they don't exist. But that doesn't mean that we don't look. And, eventually, a theory might be an advance in our understanding.

What better method for attempting to break the Standard Model would you suggest?

Uncle Al said...

Physical theory has demonstrably defective postulates.

… 1) Fermions and hadrons lack exactly identical vacuum symmetries. Baryogenesis
… 2) Given almost exact vacuum symmetries, Noether's theorem does not provide exactly conserved currents. Milgrom acceleration
… 3) Molecular extreme opposite shoes do not vacuum embed with exactly identical energies.
… 4) Molecular extreme opposite shoes do not vacuum free fall exactly identically. Quartz single crystals, enantiomorphic space groups P3(1)21 (exactly righthanded) versus P3(2)21 (exactly lefthanded) violate the Equivalence Principle.
… 5) A molecular beam of only extreme left shoes or only extreme right shoes traverses a grating. Their Schrödinger's cat wavefunction racemizes in the near-field dissipationless region, or no pattern emerges on the far side, or everything behaves. Quantum mechanics is fragile.


Sabine Hossenfelder said...


a) no
b) no

Sabine Hossenfelder said...


Not sure what you mean. We can quibble about the "quantum" in front of "gravitational". Actually, re-reading the sentence it's misleading. I think I'll scrape this in an update. Is this what you are referring to?

Sabine Hossenfelder said...


As I have explained in my book and in many places on this blog, not everything that makes predictions has scientific value. The current methods that particle physicists use to develop BSM pheno don't work, haven't worked for 30 years - that's fact. Now, I have some understanding that they tried it, but science is about correcting mistakes. That correction isn't happening. The only thing that's happening is more useless papers about fantasy-particles.

I don't think it's my task to come up with things for BSM phenomenologists to do. They should have re-thought their methods long ago but didn't. And I can't see anything is happening now.

I know that ppl in the field now try to argue machine learning is the newest thing ever, but I hope we both know that this isn't true. Not only have particle physicists used machine learning for decades, they would have employed deeper networks either which way, regardless of what was in the data. So there's no re-thinking of methods here, there's just more people now who are able to run tensorflow.

Having said this, the conclusion that I came to is that we should focus on well-defined problems, not problems of beauty. My book has the details.

Not that I'm saying this is specific to hep. Best,


papa said...

Mrs B
"Is this what you are referring to?" more interested in who is being "stung" by "sting theory".

Arun said...

Papa is referring to "sting theory".

Sabine Hossenfelder said...


Haha, now I see! Thanks for pointing out, will fix this.

Louis Tagliaferro said...

My guess is the physicist's that dislike your book or think you are a "horrible person" are unaware they have a bias against strong fundamental assumptions, empirical testability, and logical reasoning that strives to be unencumbered by human behavioral influences such as ego and self interests. Those are the reasons I follow your blog and give great consideration to what you have to say.

What troubles me most about scientific research is not that scientists thinking is hampered by bias and self-interest, it's that they are so unaware and in denial about it.

David Lambert said...

With all due respect to Stephen, that screen shot shows lots of soft hair on your event horizon. My event horizon lost most of its soft hair years ago. :-(

Don Lincoln said...

You didn't answer my question, though.

What methodology would you propose that has a high probability of advancing beyond the Standard Model? Certainly beauty is not the motivator for many of the speculative models proposed by BSM phenomenologists.

You may have answered that in your book, which I haven't read yet. It is, however, sitting on my coffee table. It's on my list of things to look at during my next transatlantic flight.

However, your answer here "well defined problems" is easy to get behind, but is vague enough as to be unhelpful.

Tanner said...

You mean your book hasn’t made you fabulously wealthy and you can now afford to be a “gentlewoman” of science?

sean s. said...

Sting Theory: physics accompanied by the music of Scott Joplin.

sean s.


Denis Boers said...

So, they try to intimidate you.

Slander, and intimidation, are the arguments of the desperate.

Perhaps the light is starting to dawn on them ?

Enrico said...

Keep up the good work of criticizing string theory and multiverse. We don’t have enough physicists doing that. I can only name three: you, Peter Woit and Lee Smolin. That makes all of you special and hated. Charming isn’t it? But we need quality control in physics research. Or they can just call it math research. But real mathematicians will call it crap.

Why is the black hole information loss a problem? The information is simply inaccessible to observers outside the event horizon. It doesn’t mean they disappeared. If singularity exists, the particles are suspended in time dilation not destroyed.

Sabine Hossenfelder said...


Well defined problems are problems of consistency. Asymptotic safety, eg, is a requirement based on that, so I think that's a good methodology to BSM. Finding a non-perturbative formulation of QFT is also a good problem. Or maybe for starters one that doesn't require renormalization as a second step (I tend to think that's a historical accident and mathematically unnecessary). The measurement problem I believe is also a well-defined problem thought that requires more work. Yes, I go on about all this in my book.

Maybe there are other problems, and you may disagree on the ones I mention. That's fine. As I say, I think it's not my job to find those people something better to do, these are merely the conclusions I arrive at. The only thing I really want is that people acknowledge what they've been doing the past 30 years didn't work, it's time to think about what went wrong, and prevent this from happening again. Best,


Sabine Hossenfelder said...


I understand you mean this as a joke but it is actually a big misunderstanding that people have. There is no money to make with books about theoretical physics, the market is far too small. The vast majority of such books never sell enough copies to even bring in royalties. It adds to this that everybody will tell you positive messages sell better than negative ones. In other words, if I had been after money I certainly would have written a different book.

The money you get from writing books that sell in such small numbers comes from the initial contracts and from translations, audio rights and so on. Then my agent gets his share and the tax takes its bite. You don't get rich from it. If it was the only income I had, I wouldn't be able to live from it. It's not nothing, but not much of an incentive either. Best,


Peter Jakob said...

Denis Boers asks:
"Perhaps the light is starting to dawn on them ?"

No, it is the glowing gas of the decomposition of the traditional physics.

Sabine Hossenfelder says:

"The only thing I really want is that people acknowledge what they've been doing the past 30 years didn't work, it's time to think about what went wrong, and prevent this from happening again."

It's hopeless; no a full-paid scientist will ever acknowledge something like this, not even under torture.

Rolf said...


"theorists mass-produce “solutions” to the black hole
information loss problem that no one will ever be able to test."

A quick google shows that you yourself
wrote 3 papers closely related to the
black hole information problem:

So you slur your colleagues for something
that you yourself contributed to ("mass production" that is,
because if each theorist contributed 3 papers in the last
15 years, this would be about 8 papers/day on this topic)?!
No wonder they put devil's horns on your head.

Phillip Helbig said...

"any unified theory of quantum gravity should offer a convincing explanation for Dark Energy?"

Sabine has already answered, but why do you think that it should?

Phillip Helbig said...

"Keep up the good work of criticizing string theory and multiverse. We don’t have enough physicists doing that. I can only name three: you, Peter Woit and Lee Smolin. That makes all of you special and hated. Charming isn’t it? But we need quality control in physics research. Or they can just call it math research. But real mathematicians will call it crap."

Argument from authority is never good. Science isn't decided by authority. Nor by vote. Nor by people criticizing other people and/or their ideas. Having said that, note that the multiverse does not necessarily have anything to do with string theory. Note also that there are many serious scientists who believe in the multiverse, and they are not bozos chasing after grant money.

If you are really interested in issues about the multiverse, rather than mud-slinging, I recommend the book Universe or Multiverse, edited by Bernard Carr.

Sabine Hossenfelder said...


That's right, when I speak of social reinforcement and the pressure to publish on what is popular, I know what I am talking about.

Don Lincoln said...


The questions you mention are theoretical ones and reasonable at that.

The questions I and my colleagues ask are far less "down in the weeds" of the mathematics. We want to understand why the universe is matter-dominant. We want to know why there are three generations. We want to know if there is a GUT-level unification. We want to understand the origins neutrino mass. We want to understand the underpinnings of the Higgs mechanism.

These are specific, but obviously vague inasmuch as we don't have a clue as to the answers.

I will grant you that a lot of these ideas...leptoquarks, hidden valleys, large extra dimensions, self-interacting dark matter, are stabs in the dark. But I don't see any mechanism that is superior. On the one hand, everybody knows that these are highly unlikely to be right...even the people making the theories. On the other hand, digging down into the question of renormalization isn't likely going to help answer those question. That approach will simply find out where the existing theories of GR and the standard model stop making sense. They don't point a direction forward.

I haven't read your book (but will!), but many of your blog posts state things that those of us staring at data plots have known for years. I admit to wondering who you talk to that doesn't understand that almost all (maybe all) BSM speculation is wrong.

I really will try to free up time to read your book.

Rolf said...

"experimentally test the validity of the gauge-gravity duality"
sounds like a pretty foundational and string theory related goal, doesn't

So you de facto continue an activity that
you call "absurd" and that "makes you laugh" if others choose to do it.

How do you feel if somebody told you:

"The subject of your newest paper is so absurd it makes me laugh." ?

Is she right?

Jonathan Miller said...

You mention a better formulation of QFT above. I have been meaning to understand the Costello and Gwilliam formulation for about 5 years now (but haven't had time). Have you ever looked into that approach (my understanding is that it is mathematically rigorous for the theories without interactions)?

Lawrence Crowell said...

I have not read it yet, but I like the apparent idea of your paper with Zingg. This does intersect some stringy physics. The holographic principle is something that has a stringy implication.

I think it would be surprising if string theory had nothing to do with the foundations of reality. The big open question is whether is is all there is at the foundations. I think to use an analogy it would be as if in the 19th century the KAM theorem of classical mechanics were understood and thought to be the roots of foundations down to atomic physics. KAM theorem is a workable mathematics for the onset of chaos, but it is not as fundational as quantum physics. It could turn out that the more baroque details of string theory and D-branes are really complex filigree that is not as fundamental as something else.

tyy said...

Beeing famous.

Sabine Hossenfelder said...


You have no idea how funny your comments are. If you think about it for more than a minute maybe it dooms on you why.

Sabine Hossenfelder said...


See my above reply to Tanner.

Ian Agol said...

Analog gravity or analogue gravity? The latter seems preferable - the former hints that it might be an alternative to “digital gravity”.

Sabine Hossenfelder said...


"We want to understand why the universe is matter-dominant. We want to know why there are three generations. We want to know if there is a GUT-level unification."

Sure, we always want to explain more than we currently can. We all agree on that. The question is how to go about it. I am saying that focusing on problems that are merely a perceived lack of beauty is not good methodology. There's no reason to think it works, it has not worked throughout history, and the data say it doesn't work right now either. Why then do you and your colleagues insist on using methods that work so badly?

And please read the book, I am tired of having to repeat all of this endlessly. Best,


Sabine Hossenfelder said...


It's analog(ue) as in analogy. The spelling is ambiguous. I flip back and forth between them. You are correct in that analog can be mistaken for emphasizing it's not digital. On the other hand "analogue" solves the problem only to the extent that it's an unfamiliar spelling so that no one knows what it means until they look it up and are returned to analog.

Denis Boers said...

Peter Jakob : " the glowing gas of the decomposition of traditional physics".

Of course, what people are talking about here, is fundamental physics.
Sabine estimates about 15.000 theorists work on it worldwide.
Still, it is only a small part of the edifice of physics.
That small - but important- part lost its way, and the efforts of Sabine, Lee Smolin and Peter Woit try to open up options before ways of thinking become so heavily institutionalized that no return to sanity is possible - for fundamental physics.
If they succeed, theorist of the late 21st century will concede that fundamental physics had a lost generation, but got back on track after the first decennia of this century.
If they don't, the field may indeed degenerate altogether.

Then, as she has pointed out, the cognitive biases that caused this are at work in other fields as well, within physics and without. She has mentioned paths to improve on the way things are done. However, improvement is not perfection, and we may have discovered that perfection is impossible. Even then, look at the incredible edifice this imperfect yet perfectible mind has built over the centuries.

Let's go easy on the gloom and doom.

Jonathan Starr said...


I always thought that the ultimate achievement in the quest to spread knowledge was to get bodied by a theocracy like Socrates. Unfortunately modern times have taken the luster off the phrase "corruption of the youth", it doesn't mean quite what it used to...

But I think you have perhaps achieved a new high-water mark. I can only hope that someday my achievements approach the sublime level you have surmounted. I would be truly honored to be worthy of having horns and an evil mustache drawn on a picture of me on a Wikipedia page for the crime of spreading knowledge.

I didn't think my opinion of you could go up, but it just did. Sorry for the hero worship I couldn't resist.

jamjam said...

You rock those horns, by the way.

I can easily imagine you as a quantum gravity incarnation of Maxwell's demon in one of your musical numbers -- about a thermodynamically rich aspect of black holes, say.

The Universe said...

Oh Sabine, you will soon wish you were still working in the foundations of physics. Get back into it as soon as you can.

John Duffield

Don Lincoln said...

You ask why we use methods that work so badly...I guess I don't think we do.

Beauty is insufficient for a theory. So what? This is well known in the experimental community. The Higgs mechanism wasn't beautiful, and it was real.

I'll grant you that there are some SUSY religionist people. I don't know anyone who takes them very least among the data crunchers.

And a lot of the ad hoc ideas that people have come up for BSM aren't beautiful at all. But they're ideas at least. There is no reason to rule out ideas, so it makes sense to look for them.

I think the core point is that physics is hard and it takes time. The Newtonian gravity unification was 350 years ago and the E&M one was 150 years ago. EW was 50. It wouldn't shock me if it took 50 or 100 years for the next correct idea.

No need to respond. Maybe I will have something to say in response to your book. But I presume the ideas mirror those on your blog, which is why I post here.


Enrico said...


Argument from authority? The authorities are in the string theory and multiverse camp. Read Woit’s book, Not Even Wrong, to find out why he’s criticizing string theory. Clue: Not to ridicule and annoy the authorities (though that is inevitable). My favourite chapter is about string theory and Maharishi.

Multiverse is also in the Many-Worlds Interpretation of QM. I will wear my sunglasses today to polarize sunlight’s photons and create billions of copies of myself in the multiverse. Heaven and hell are in the multiverse inhabited by angels and demons. So sayeth Dr. Pangloss, Professor of theology, cosmology and metaphysics.

Sabine Hossenfelder said...


The prediction of the Higgs dates back to the 1960s, that was when things were still working. The Higgs is not a prediction based on beauty, it's a prediction based on necessity. Yes, it's ugly. And yes it works.

You may not think that the BSM people use arguments from beauty, but they do. They rely heavily on wanting to have unification and naturalness, which are aspects of beauty. They want explanations for what they think are "suspicious" coincidences. Read your own comments!

They also want to be able to produce papers quickly, ie convenience plays a role, though they tend to speak of it as "fruitfulness" - more arguments from beauty. The beauty-issue however is only one aspect of the more general pressure to work on what is popular.

Again, PLEASE read the book. The whole reason I wrote it is that you and your colleagues are not aware what you are doing, and your comments illustrate exactly the problem I am talking about. Best,


Rolf said...

Sigh, the problem is that you often seem to think
"less than a minute" about critical quality comments
(your recent exchange with opamanfred is a good

OK I try again:
In your newest paper with Zingg, that you refer to
in this blog post, aims to eventually enable physicists to, quote,
"experimentally test the validity of the gauge-gravity duality".
This is clearly a foundational subject, so your
statement "I don’t even work in the foundations of physics any more."
is simply incorrect. OK?

Moreover the paper is string related.
So you are de facto still also a string theorist.
(Physicists who write string
related theory papers are also string theorists.)

But then you slur other colleagues
who do the same thing with:

>(String theorists) get paid well for their remarkable contributions
>to human knowledge. If that makes you laugh, it’s the
>absurdity of the situation,

Really Sabine, your are also still paid, aren't you?
How can you accept this money but denigrate your colleagues
who do the same thing?

Sabine Hossenfelder said...


It's condensed matter physics, hence not foundational. Frankly I find it outright bizarre that you try to "correct" my own statement about what I work on.

"So you are de facto still also a string theorist.

Well, wow. Speak of mansplaining. Not only do you not understand there is zero string-physics in the paper, you also seem to mistakenly think I once worked on string theory. But since you don't think that I know what I work on, why don't you go and ask literally anyone in the community whether I am a string theorist? I give it 0.01% chance that someone will say yes, and the other 99.99% will vomit when they hear that yes.

Besides this, I have never denigrated anyone for accepting funding for their research. I have no idea where you get your "knowledge" from, but maybe you should give it some more effort.

Peter Jakob said...

I am trying to comment probably for the very last time on your blog. It is becoming increasingly boring to read always the same arguments. Do you really have nobody in your blog-community, being able to propose some radical cut in such bla-bla-bla-discussion and to start from the very beginning of our physical description of Nature once more? Ok, you personally don't like the idea. You select out my comments tending in that direction. I have to respect this; it is Your blog. But that also nobody else is ready to push the "reset-button" in our science, it is very disappointing for myself.

Sabine Hossenfelder said...


There's no reset button, that's not how science works. And I don't approve comments in which people propose their own theories for something. This has nothing to do with you personally, it's just that if I'd do this, that would be the vast majority of comments and it would be impossible to have any interesting exchange here.

Rolf said...

> It's condensed matter physics, hence not foundational.

In your paper the condensed matter physics has the sole purpose to
throw light at foundational issues.
Your paper is clearly on foundational physics.
This is where your heart is.

> there is zero string-physics in the paper,

The AdS/CFT correspondence plays a central role in your
paper. Open its Wiki entry. It is listed as a special
topic of "string theory".
The paper clearly contains "string-theory related theory".

> why don't you go and ask literally anyone in the community whether I am a string theorist?

I only claimed you are ALSO a string theorist.
Some of your papers contain string theory related theory.
You currently engage in a string-theory related activity.

>I have never denigrated anyone for accepting funding for their research.

You did, in the passage I quoted:

>[String theorists] get paid well for their remarkable contributions
>to human knowledge.

The ironic "remarkable" together with the "well"
is a statement that you argue that their results are
not worth what they get paid.

>If that makes you laugh, it’s the
>absurdity of the situation,

Strengthens the above statement. You state that
is absurd that they get paid so well for their results.

Sabine Hossenfelder said...


You are digging yourself deeper and deeper into a hole. You clearly don't know what I mean when I refer to the foundations of physics. Maybe try to find out. Hint: It's explained in my book.

"The paper clearly contains "string-theory related theory".

Yeah, that's right, it's string theory-related. That's because, believe it or not, string theory might be useful outside the foundations of physics.

"You state that
is absurd that they get paid so well for their results.

That's right, I think they're not worth the money, but I don't blame them for taking it.

And no, it's not OK that you continue make false statements about my work and about my opinions.

Uncle Al said...

The pendulum equation, T = 2(pi)sqrt(L/g), is simple. elegant (Equivalence Principle - no bob appears), and wrong.
... we can ignore the other terms.

Religion worshiping a zombie versus one cherishing cow excrement is meaningless comparison. Derivation cannot exceed postulates. Falsification violates postulates and is therefore intolerable to both parties.

A flailing science tested by a “lesser” empirically valid science is being a poltroon in defense of being wrong. If one microwave spectrometer undergrad-day threatens

invest in the undergrad first. Look

Phillip Helbig said...

"You have no idea how funny your comments are. If you think about it for more than a minute maybe it dooms on you why."

dooms ---> dawns

Rolf said...

> You clearly don't know what I mean when I refer to the foundations of physics.

You write about the AdS/CFT duality in chapt. 8 of your
book, including its relation to condensed matter physics.
And your book is about what you call foundations of physics,
or is it not?

Phillip Helbig said...

"Argument from authority? The authorities are in the string theory and multiverse camp."

Sorry, but I have to call "bullshit" here. I'm currently reading a piece by Smolin. He has a different opinion on some things than, say, Martin Rees, but either neither present themselves as an authority (my view), or both do. You can't just brand people you don't like as authorities, and claim that those you do are somehow suppressed by the establishment.

"My favourite chapter is about string theory and Maharishi."

For the record, I am not a strong proponent of string theory, for what that's worth (not much). But comparing it with the Maharishi? It is exactly hyperbole of this stuff which prevents a polite and useful discussion.

"Multiverse is also in the Many-Worlds Interpretation of QM."

Yes. But it is (probably) not the same Multiverse.

"I will wear my sunglasses today to polarize sunlight’s photons and create billions of copies of myself in the multiverse. Heaven and hell are in the multiverse inhabited by angels and demons. So sayeth Dr. Pangloss, Professor of theology, cosmology and metaphysics."

Would Karl Lagerfeld say that your sunglasses go well with your tinfoil hat?

Rolf said...
This comment has been removed by the author.
Peter Jakob said...

No Sabine,

in that point you are completely wrong; there is a reset button in science, as well as in each human activity. One important point of the "ideology" of science your generation has been indoctrinated in the third part of the twentieth century was to blindly believe: there is just one-way ticket to the very top of science; to absolutely follow your "instructors". Stalinism was one other example (of course not in science, but in the lives of millions). As a clever and deeply feeling human being, as you are, you have always a right and (if you think for your daughters generation) even a duty, to stop the blind running and ask, who gives me the direction, and why (paid from whom)? My proposal (would you be my daughter, I would say: my advice) is not to ask Newton (what do you think about quantum gravity), Einstein (what do you think about quantum speed of light), or Hawking (what do you think about quantum black hole), but to ask Nature herself: what do you think about your universal quantized processes and phenomena? In order to hear and understand the Nature's answer, we have to go to our scientific fundament, to define all physical quantities, units, and constants in agreement with the natural universal quantization. This is the reset button for our physics of 21st Century. All remaining is at the best a history of science.

Dear Sabine, I wish you will live healthy twice as long as your father. But it would be a catastrophe for the next two generations of young scientists to have to wait until you will reach the same level of disappointment with our physics as I have reached some decades ago. It is not necessary. You have the possibility to learn from the past "experiences" of other persons. And I am sure, it would not negatively influence your blog, as you afraid: "that would be the vast majority of comments and it would be impossible to have any interesting exchange here."

Sabine Hossenfelder said...


Just because my book is about the foundations of physics doesn't mean it contains no mentioning of other areas of physics. If you look up the respective paragraph that you refer to, you will notice it begins with "Other string theorists have left behind the foundations of physics entirely..."

Let me note that after insisting that I work on something I don't work on, you now try to educate me about what I wrote in my own book.

Rolf said...

The quote refers to physicists who have the intention
to use string theoretical methods to understand problems in nuclear or
solid-state physics as their primary goal.
But you tell us in the post that your primary goal is to eventually
"experimentally test the validity of the gauge-gravity duality".
Do you really want to tell us that you have become
a solid-state physicist?

And even if you had become one: you still call
this type of physicist in the quote in your last comment "string theorist".
And you berated "string theorists". So in any case
you berated a category of physicists to which
you also currently belong.

Sabine Hossenfelder said...


"Do you really want to tell us that you have become a solid-state physicist?"

The systems we look at aren't solid state, they're non-viscous fluids. How much will it take for you to notice that you have no idea what you are even talking about?

"you still call
this type of physicist in the quote in your last comment "string theorist".
And you berated "string theorists". So in any case
you berated a category of physicists to which
you also currently belong."

First and foremost, I am indeed highly critical of myself. As I told you many comments earlier, the reason I keep going on about the pressure to publish on what is popular and the difficulty of getting funding for other things is because I know what I am talking about. You continue to miss the point, even though I told you already you miss the point.

Second, you simply misunderstood the sentence. Read it again: some string theorists have left behind the foundations and now work on X doesn't mean everyone who works on X is a string theorist. Finally got it? I am not a string theorist, I have never been a string theorist, and I doubt I will ever be one. And as I already told you, since you seem to have difficulties accepting this statement from me, go ask someone else, preferably someone who knows what string theory is.

Having said this, this exchange is beyond stupid, is wasting my time and I will not approve further comments from you.

Denis Boers said...

Sabine, I sometimes wonder whether you are not a tiny bit too tolerant of silly comments.
Such as the guy who pretended to teach you what you work on, what you write about and what you just said. He sounded like John Cleese in " The Argument Clinic " ( ).

Enrico said...


For the naïve “bullshit” caller, who are the authorities? Mostly deans and tenured professors of prestigious universities. Martin Rees is definitely an authority. Dean (or Master) and Professor at Trinity College, Cambridge U; President of Royal Society; Royal Astronomer of UK. The deans have authority to prioritize areas of research for their departments (we need to hire postdocs who specialize on string theory)

Woit did not invent the link between Eastern mysticism and quantum mechanics. The role of consciousness in the measurement problem goes back to Wheeler in 1950s or earlier. The book Tao of Physics popularized it in 1980s. Since then, mystics, crackpots and physicists joined the bandwagon. Sometimes they’re the same people.

The multiverse in QM and string theory is the same nonsense. No mention of bubble universes from eternal inflation? Read again Universe or Multiverse.

As for my sunglasses and your tinfoil hat, read Gribbin’s In Search of Schrodinger’s Cat. You don’t need a tinfoil hat in the photon-polarizer experiment. But you can wear your hat for fun.

Shantanu said...

Sabine: I thought (from your comments on Woit's blog a few years back) you also had secured a grant on ADS/CFT and were looking to hire a postdoc in that field?

Sabine Hossenfelder said...

Right, the coauthor on the paper, Zingg, is mentioned postdoc.

Goopta Uncle said...

I am an unemployed (due to health reasons)31 year old non theoretical physicist,I have studied up to masters level in electronics and communication engineering so I have good grasp of math.I wanted to continue with research in my field but I now find the subject of communications engineering to dry and besides I don't seem to have any aptitude for the subject.
I was very interested in theoretical physics as a teenager but it was just a short lived phase.After the death of my 57 year old mother from cancer around 7 months back,I started becoming very interested in Theoretical physics once again and it is helping me deal with the pain of her loss.
I am currently learning supersymmetry(even though it may not describe nature) from YouTube.The lectures are by prof Romesh kaul from the Indian institute of mathematical sciences,you should check them out it's awesome.I know supersymmetry may not be a correct theory of particle physics since nothing has been detected by lhc even after 10 years,but I don't think there is any harm in learning such a beautiful theory.Btw I am from india.Would love to hear your response to my rambling.

Phillip Helbig said...

"Mostly deans and tenured professors of prestigious universities. Martin Rees is definitely an authority."

And Lee Smolin is a homeless tramp? According to Wikipedia, he is "a faculty member at the Perimeter Institute for Theoretical Physics, an adjunct professor of physics at the University of Waterloo and a member of the graduate faculty of the philosophy department at the University of Toronto", which sounds like an authority to me.

My points are: a) That you can find prestigious and non-prestigious supporters on both sides of this (and many other) argument(s). Saying that theory X must be wrong because theory X is supported by scientist Y who has tenure is just not a rational argument: especially because theorist Z, with tenure as well, disagrees. Moreover, penniless postdoc A agrees with X and B agrees with Y. b) In their writings, most proponents, on both sides, understand the art of civil debate and don't resort to ad hominem attacks.

Louis Tagliaferro said...

@Don Lincoln

Don Lincoln said…

“And a lot of the ad hoc ideas that people have come up for BSM aren't beautiful at all. But they're ideas at least. There is no reason to rule out ideas, so it makes sense to look for them.”

What instantly comes to mind when I read that comment is, it is sensible but not efficient. Physics is likely to advance more quickly if it is directed by an assessment of probability when applying resources rather than prioritizing ad hoc ideas, popularity, and career interests.

Don Lincoln said … “I think the core point is that physics is hard and it takes time. The Newtonian gravity unification was 350 years ago and the E&M one was 150 years ago. EW was 50. It wouldn't shock me if it took 50 or 100 years for the next correct idea.”

Max Planck wrote to Einstein about his intention to work on gravity, “As an older friend, I must advise against it, In the first place, you won’t succeed, and even if you do, no one will believe you.” Scientific advancement may unnecessarily be slowed because of career interests and a need to conform to what the community deems acceptable. Those time frames could be long because ad hoc ideas that conform are rewarded while ideas that challenge long accept beliefs are chastised. An unseen planetary body and invisible dust were among the ideas proposed to explain a precession in Mercury’s orbit that didn’t conform to Newton’s equations. I see “dark energy” in a similar context.

While arguments often cite that GR has been around for over 100 years I think it took several decades before it was widely accepted by the physics community. However, now that it’s entrenched, as was done with Newtonian gravity before it, the community tends to force ideas into its framework rather than challenge it. Scientists are supposed to learn from past mistakes, not repeat them.

Lawrence Crowell said...


There are connections between solid states physics and quantum field theory. Largely this is because the crystal lattice is a discrete group model of QFT. The vacuum in solid state physics is the ground state for phonons. It also turns out the physics of HiTCs is remarkably similar to AdS_2/CFT_1.

Anthony Verbalis said...

Sabine, it may be that in this Universe, your talents and knowledge are, and will be, less than fully appreciated. So my suggestion is that you get yourself over to one of them multiverse universes where that is not the case.

Me? I would like to hop over to a universe where physicists were smart enough to never come up with multiverse theories in the first place. There must be at least one out there someplace.

JimV said...

Mr. Goopta, I am sorry for your loss, and can't help you much with prospects or your studies, but I can ramble with the worst of them.

Dr. Hossenfelder will probably reply for herself but I don't think there is harm in studying whatever aspects of science interest you, nor will Dr. Hossenfelder, I think, but her argument is that there is not much point in funding further research in supersymmetry or encouraging working physicists to specialize in such research since it has not produced any tangible results.

Personally I like the multiverse concept as an interesting and perspective-expanding idea but there again it has not produced any useful results so probably doesn't deserve much if any research funding. There are so many problems our civilization is facing now which need good minds working on them that we really can't afford to focus on much else.

Don Lincoln said...

@Louis Tagliaferro

GR was accepted in 1919, a mere four years after its proposal. The Eddington observation on 1919 is what rocketed Einstein to a household name.

Regarding your advice to do research based on an assessed probability of it working, well good luck with that. If that were possible, we'd have done it a long time ago.

I agree with some of Sabine's criticisms on how science is done to a degree, but I think she entirely overstates them. There are social pressures, accepted approaches, etc., but they're not universal. There are lots of crazy ideas being tested.

The real problem is that nobody has a clue what to do. Even you. Even Sabine. Even me. If we did, we'd do it and be famous. And, yet, here we are.

Sabine Hossenfelder said...


I can't do the science I want to do simply because I don't have the money. I know a lot of people who, once they realized this is how academia works, left. That I'm still here is somewhat of a miracle. The majority of researchers who stay in the system are those comfortable with doing what there is money for, which is the same stuff over and over again, stuff that is done by too many people already.

You have benefited from the system, you still benefit from it, and this means you are likely to not perceive major problems with it. It's called selection bias. You should factor it in when you look at the evidence. You don't.

You ask me what to do, I told you, now you say I don't have a clue while entirely disregarding the arguments I offered. And you wonder why there is no progress in your field?

Don Lincoln said...

I haven't read your book. I will, as soon as I can. Perhaps I will understand your criticisms better than I do from sporadically reading your blog.

I don't know you funding situation, so I won't comment on it. I got lucky and got a permanent position. It didn't have to go that way. Had it not, I would have picked a different path. As it happens, the job I got isn't really the one I wanted, nor the one at which I would have been more successful, but such is life.

And don't lecture me about selection bias. I'm as good a scientist as you are, albeit with a different bent. I see the vast majority of our postdocs not get academic posts. I'm fully aware of the broader world and the fact that there are other perspectives. Further, I share your frustration with the lack of progress in my lifetime. On the other hand, I see no viable alternative to how things are going now. It is extremely unlikely that a theorist will make the next valuable advance. We're waiting on the experiment that reveals the path forward. And the proper approach is to study phenomena at higher energy and at finer precision to find discrepancies.

Or if you have a testable hypothesis, that can be tested with current or near-future technology, we'll give it a go. I'm open to ideas from anyone who has the training and discipline to have something valuable to say. You fall into that category.

If it turns out that the premise of your book and world view arises solely from frustration that you think that academy doesn't properly appreciate your approach to science, I'm going to be very disappointed.

The next long trip I go on, your book will tag along.

Louis Tagliaferro said...


I’m not sure where I’d heard GR wasn’t widely accepted for several decades after it came out, I’ll take your word I was wrong and it was after Eddington’s observations.

I wasn’t blessed with the level of intelligence that most PhD’s in physics have, but I was born with a talent for seeing better than most how things like self-interests, group think, and ego affect our behavior and actions much more than we realize. Scientists are as susceptible and guilty as everyone else, and most don’t know or would acknowledge how much it influences their work. That’s why I included the quote to Einstein by Max Planck, that’s the norm in thinking not the exception, even for scientists. At the time it was written there already was a lot of evidence Newtonian gravity wasn’t a complete or fully accurate account of its influence. Yet one of the world’s most preeminent scientists of his time was advising a junior not to attempt working on it. That same kind of thinking has not changed today.

As an objective observer who mainly wants to see more scientific answers discovered in my lifetime, there is much circumstantial evidence when coupled with an understanding of past and current human behavior that points to more promising probabilities for finding those answers however; they are likely a lonely, unfunded, possibly career ending direction where most researchers won’t go, sincerely believing their reasoning is other than that truth.

Phillip Helbig said...

"The majority of researchers who stay in the system are those comfortable with doing what there is money for, which is the same stuff over and over again, stuff that is done by too many people already."

I'm not sure what "the system" is here. Sure, those who stay are usually comfortable with it (including those who can't get anything better), otherwise they wouldn't stay. In some cases, one might have to actively get money, but most tenured academics don't, at least not for their own salary. For students, postdocs, etc, sure, but the whole idea of tenure is independence from the gravy train. People with permanent jobs in academia have a large amount of academic freedom, and I doubt that most do the same stuff over and over again.

If by "the system" you mean some niche branch of physics where buzzwords dominate peer review then, yes, you might be right (I don't know since I have no experience there).

Of course, someone who has been working as, say, a radio astronomer, or even a radio astronomer working on pulsars, for decades is very probably not doing the same stuff over and over.

Denis Boers said...

Off topic ... about that new haircut ... they say everything is time-reversible in physics, right ?? ;-)

SRP said...

Lost in Math has some interesting passages where people pursuing non-mainstream but not obviously crazy ideas faced a brick wall of indifference and/or hostility. So it isn't just a matter of positive reinforcement of the popular, but of active discouragement of the unpopular.

Sabine Hossenfelder said...


If you don't want me to lecture you on selection bias, then please stop quoting your own opinion as if it was an objective argument for anything. You say you think I overstate the problems. You did not take into account that you are likely to think so because you are in the sample of those who do well in the current system. Neither, for that matter, did you actually consider any of the arguments I raised.

Fact is the current methodologies have worked badly. Fact is arguments from beauty have not historically worked well. Fact is that intelligence does not protect from thinking biases and scientists today take no measures whatsoever to alleviate their biases.

I am pretty tired of people who call themselves scientists disregarding the facts and instead complaining I am too negative. The evidence is right in your face. Deal with it.

You further argue that the way forward is experiment. I have no objection to this of course - more experiments are always good - but we arguably cannot do all experiments that we'd want to. And when it comes to selecting experiments, then it becomes very relevant which theories we consider worth testing.

Having said that, I am a theorist and the research I'd want to do is primarily theoretical. I can't even tell you what experiment to make because I don't have the funding to work out what's necessary. In any case, I'll send you an email about that. Best,


opamanfred said...

@ Sabine, @Don
The problem with psychological biases, is that we all have them and always did, including those who (like you) like to denounce other people's biases. Incidentally, science has worked very well in the past even though past scientists were arguably even more culturally biased than we are today. How do you explain that? How come biases are so important today, but did not slow down science in the past?
As an example of your own bias, I could just make a mirror-image of your paragraph in response to Don:
"You have benefited from the system, you still benefit from it, and this means you are likely to not perceive major problems with it. It's called selection bias. You should factor it in when you look at the evidence. You don't."
which would become:
"You have been shunned by the system, you are still shunned by it, and this means you are likely to overemphasize nonexistant or minor problems with it. It's called selection bias. You should factor it in when you look at the evidence. You don't. "

Sabine Hossenfelder said...


In my book I have a section that is especially dedicated to the claim "but it has always worked before" and I also debunk this - rather silly - argument in all of my talks. Science today is not what it was a century ago. It's just not. Society has changed, science has not adapted. Look at the facts.

opamanfred said...

Thank you for the "silly" and the womansplaining*.
Society has changed many times since science was invented. Newton's times were very different from Einstein's, and Einstein's from Feynman's. What is so special about our today?
Second, which you did not address in your response, what about your own biases?
For instance, we all think that we are very special individuals, but in reality most of our traits are very average. It's indeed a selection bias, in the sense that we notice the interpersonal differences much more than the similarities.
Perhaps your conviction that our epoch is a very special one suffers from the same sort of bias.

* From Wikipedia: "(of a woman) to comment on or explain something to a man in a condescending, overconfident, and often inaccurate or oversimplified manner"

Sabine Hossenfelder said...


I explain in my book how science is different. I even have numbers. How about you read it?

I explain things to you in an oversimplified manner because it seems necessary. You make an argument of the sort "but it's always worked before" without factoring in that today isn't yesterday. That's not a good argument.

Of course I am biased. Guess what? I also discuss this in my book.

That I too am biased and cannot do much about it is the very reason why (as I explained in this comment thread further up) I do not want to tell anyone what to do, and am in fact somewhat annoyed that people insist I do. The only thing I can tell you we really should do, regardless of whether you think about the current situation, is to take measures that limit our personal biases. Should it turn out that it doesn't make any difference, well, I'll stand corrected, and agree that there was no problem after all.

I don't think I'm special. Does this make me special?

JimV said...

"How come biases are so important today, but did not slow down science in the past?"

Personally, I think it did, always has, and always will. Leibniz and Newton clashed over the development of calculus and whether Newton's Law of Gravity (spooky action at a distance according to Leibniz) made sense philosophically. Galileo clashed with a lot of people. Aristotle clashed with Democritus.

My guess is, the rate of scientific progress varies with the availability of measurement equipment to do new experiments and get new data. People will always disagree philosophically (as we see here every day); it takes hard data to force consensus (and even then ...).

And yet, as I look back at my own career, what bothers me are those times I did not fight hard enough for my ideas against opposition; because, dang it, I was right! Well, maybe not always.

Bias is getting more and more important as testing gets more and more expensive compared to available resources. The bias against doing anything about over-population and climate change will probably doom our civilization because by the time the hard data convinces everyone, it may be too late. Meanwhile as I walk everyday I can count 100 cars going by (in both directions) within five minutes, most with a single occupant. I can only channel Uncle Al and urge, "Think, people, think!"

Don Lincoln said...

I tell you what. I'll stop stating opinion as fact when you do.

Mind you, it is common for smart people with strong opinions to do that. It's an occupational hazard for both of us.

It is true that I've done respectably in the existing system. Maybe you haven't. I don't know. But it's easy for someone to say that they have not done well under the existing system because their genius is not well appreciated. In fact, both you and I get emails all the time from people who make exactly that claim. I'm not saying that you qualify in that crank category...after all, you have far more knowledge than many of our pen pals...but you must admit that it sounds similar.

I'm 100% behind testing the foundations of physics. In fact, the costs associated with the types of measurements you are proposing are quite modest. It's not my personal expertise, mind you, but it's pretty clear what the cost range would be. The problem is that testing foundational QM is not popular. It's not popular because many tests have been done and standard QM works.

I assume you know what to do, which is to look at existing literature and see what constraints have been set on the variables you think need measurement. It would also be helpful to see if existing experimental setups can be modified to make the proposed measurements. If they do, then it might be that the measurements could be done by a student just to see if they are possible. When that is done, it leads to more serious grant prospects.

Given the recent interest in quantum computing, it is very likely that there is money available for tests of QM. What would be key is for you to understand if your proposed idea has not already been ruled out by previous measurements. Further, if there is a deep and overlooked aspect of pilot waves, hidden variables, or something like that which has not been tested, I'm sure you'd have people interested in doing the test.

In any event, if you want to propose a test, it means that you'll have to come part of the way towards the experimentalist. Nobody's going to do your work for you. It's like the people who send you emails who claim that they have a theory of everything...all that is needed is for you to do the math for them.

And I'm a little tired of people complaining that people do not take their ideas seriously. Perhaps you should follow the advice you gave me. Deal with it.

Sabine Hossenfelder said...


As this blogpost tells you I have done reasonably well in the system, at least so far. It is not my own situation that I am worried about. What worries me is that I know how the game works and that I can see what it leads to. It leads to a lot of wasted money.

I have in fact in my book not written about what what I work on - as I said in my blogpost - to avoid the impression I am complaining about my own situation. That's not the point, and I am disappointed, to say the least, you are trying now to wiggle out by making exactly this claim. You are the one who asked what I would propose. I told you. Now you try to use my reluctant answer it against me.

Of course I have a lot of opinions and I don't blame you for having opinions. I find it tiresome, however, that scientists go around and offer their opinions as if they were facts.

The facts are: Arguments from beauty have not historically worked well. The current methods of theory development are based on arguments from beauty. The current methodologies have not worked for 40 years, yet theorists continue to use them. In other words: Fact is theoretical physicists insist on using methods that demonstrably work badly.

Fact also is: All humans have cognitive biases and yet scientists do not presently take any measures to prevent those from affecting their research. Regardless of what you think about whether there is a crisis in the foundations of physics or not, this has to change.



opamanfred said...

The foundations of QM have been studied from A to Z (from Aspect to Zeilinger...). I don't know why you think otherwise. Not a single deviation has ever been observed from the standard QM predictions, and the possible loopholes (which would allow for local hidden variables) are very unlikely indeed. There is a good book by Nicolas Gisin ("Quantum Chance") on this topic. Gisin measured quantum entanglement over distances of literally kilometers, using the Swiss commercial optical-fiber network.

What has been less studied is the effect of gravity on quantum systems, for the simple reason that gravity is very weak, so hard to measure. But there are many proposed experiments on this topic, both table-top and fancier stuff on satellites. I'm not aware of any real experiments already done though. Personally, I think some new physics will come out of these experiments one day or another.

Just to be sure, your criticism about beauty, biases, etc.. addresses only very fundamental physics (elementary-particle, quantum gravity...) - or is it more general?

Sabine Hossenfelder said...


My criticism about biases is general, applies to all of science. Beauty is a specific bias that is relevant mostly in the foundations of physics.

Kaleberg said...

I come here for the great debates of the age, and I am rarely disappointed.

My first exposure to the idea of multiple universes was in a lecture on Kripke's doxastic and epistemic logic formulated in the 1950s and 1960s. Kripke casually suggested, based on the model, that one could thing of it as navigating multiple universes. According to the lecturer, a few years later Kripke tried to take it back. It's a pity he couldn't.

I wouldn't compare modern high energy physics to physics in the late 19th century. If nothing else, that was a great age of experimentation and explanation. Physics was on a roll, it was just that there were an increasing number of untidy corners like the UV catastrophe and the inability to measure the ether.

A better analogy might be to astronomy in the middle ages. It was an expanding field of increasing accuracy. The Toledan tables were a marvel and the tide prediction problem, if Chaucer is to be believed, was effectively solved. The problem was the weakness of the underlying model. It took a lot more data and analysis before anyone could move forward. Meanwhile astronomy stagnated even as more and more beautiful theories were constructed. The new theories started out ugly and stayed that way for more than a century.

Remember, one big argument in favor of the heliocentric system before Newton was that it allowed astrologers to determine the strength of the influence of Mercury and Venus on people's horoscopes.

Greg Feild said...

Dear Sabine,

You should really check out my books.
What do you have to lose?

Greg Feild

Good luck!