Tuesday, April 28, 2015

What should everybody know about the foundations of physics?

How do we best communicate research on the foundations of physics? That was topic of a panel discussion at the conference I attended last week. Organized by Brendan Foster from FQXi, on the panel were, next to me, Matt Leifer and Dagomir Kaszlikowski, winner of last year’s FQXi video contest. And, yes, Matt was wearing his anti-quantum zealot shirt :)

It turned out that Matt and I had quite similar thoughts on the purpose of public outreach. I started with pointing out we most often have two different aims, inspiration and education, that sometimes conflict with each other. To this Matt added a third aim, “activation,” by which he meant that we sometimes want people to react to our outreach message, such as maybe signing up for a newsletter, attending a lecture, or donating to a specific cause. Dagomir explained that making movies with sexy women is the way to better communicate physics.

As I laid out in an earlier blogpost, the dual goals of inspiration and education create a tension that seems inevitable. The presently most common way to inspire the masses is to entirely avoid technical terms and cut back on accuracy for the sake of catchy messages – and heaven forbid showing equations. Since the readers are never exposed to any technical terms or equations, they are doomed to forever remain in the shallow waters. This leads to an unfortunate gap in the available outreach literature, where on the one hand we have the seashore with big headlines and very little detail, and in the far distance we have the island of education with what are basically summaries of the technical literature and already well above most people’s head. There isn’t much in the middle, and most readers never learn to swim.

This inspiration-education-gap is sometimes so large that it creates an illusion of knowledge among those only reading the inspirational literature. Add to this that many physicists who engage in outreach go to great lengths trying to convince the audience that it’s all really not so difficult, and you create a pool of people who are now terribly inspired to do research without having the necessary education. Many of them will just end up being frustrated with the popular science literature that doesn’t help them to gain any deeper knowledge. A small fraction of these become convinced that all the years it takes to get a PhD are really unnecessary and that reading popular science summaries prepares them well for doing research on their own. These are the people who then go on to send me their new theory of quantum mechanics that solves the black hole paradox or something like that.

The tension leading to this gap is one we have inherited from print media which only allows a fixed level of technical detail, then often chosen to be a low level as to maximize the possible audience. But now that personalization and customization is all en vogue it would be possible to bridge this gap online. It would take effort, of course, but I think it would be worth it. To me bridging this gap between inspiration and education is clearly one of the goals we should be working towards, to help people who are interested to learn more gradually and build their knowledge. Right now some bloggers are trying to fill the gap, but the filling is spotty and not coordinated. We could do much better than that.

The other question that came up repeatedly during the panel discussion was whether we really need more inspiration. Several people, including Matt Leifer and Alexei Grinbaum, thought that physics has been very successful recently to reach the masses, and yes, the Brian Cox effect and the Big Bang Theory were named in this context. I think they are right to some extent – a lot has changed in the last decades. Though we could always do better of course. Alexei said that we should try to make the term “entanglement” as commonly used as relativity. Is that a goal we should strive for?

When it comes to inspiration, I am not sure at all that it is achievable or even particularly useful that everybody should know what a bipartite state is or what exactly is the problem with renormalizing quantum gravity. As I also said in the panel discussion, we are all in the first line interested in what benefits us personally. One can’t eat quantum gravity and it doesn’t cure cancer and that’s where most people’s interest ends. I don’t blame them. While I think that everybody needs a solid basic education in math and physics, and the present education leaves me wanting,  I don’t think everybody needs to know what is going on at the research frontier in any detail.

What I really want most people to know about the foundations of physics is not so much exactly what research is being conducted, but what are the foundational questions to begin with and why is this research relevant at all. I have the impression that much of the presently existing outreach effort doesn’t do this. Instead of giving people the big picture and the vision – and then a hand if they want to know more – public outreach is often focused on promoting very specific research agendas. The reason for this is mostly structural, because much of public outreach is driven by institutes or individuals who are of course pushing their own research. Very little public outreach is actually done for the purpose of primarily benefitting the public. Instead, it is typically done to increase visibility or to please a sponsor.

The other reason though is that many scientists don’t speak about their vision, or maybe don’t think about the big picture themselves all that much. Even I honestly don’t understand the point of much of the research in quantum foundations, so if you needed any indication that public outreach in quantum foundations isn’t working all that well, please take me as a case study. For all I can tell there seem to be a lot of people in this field who spend time reformulating a theory that works perfectly fine, and then make really sure to convince everybody their reformulation does exactly the same as quantum mechanics has always done.

Why, oh why, are they so insistent on finding a theory that is both realist and local, when it would be so dramatically more interesting to find a theory that allows for non-local information transfer and still be compatible with all data we have so far. But maybe that’s just me. In any case, I wish that more people had the courage to share their speculation what this research might lead to, in a hundred or a thousand years. Will we have come to understand that non-locality is real and in possible to exploit for communication? Will we be able to create custom-designed atomic nuclei?

As was pointed out by Matt and Brendan several times, it is unfortunate that there aren’t many scientific studies dedicated to finding out what public outreach practices are actually efficient, and efficient for what. Do the movies with sexy women actually get across any information? Does the inspiration they provide actually prompt people to change their attitude towards science? Do we succeed at all in raising awareness that research on the foundations of physics is necessary for sustainable progress? Or do we, despite our best intensions, just drive people into the arms of quantum quacks because we hand them empty words but not enough detail to tell the science from the pseudoscience?

I enjoyed this panel discussion because most often the exchange about public outreach that I have with my colleagues comes down to them declaring that public outreach just takes time and money away from research. In the end of course these basic questions remain: Who does it, and who pays for it?

In summary, I think what we need is more effort to bridge the gap between inspiration and education, and I want to see more vision and less promotion in public outreach.


CapitalistImperialistPig said...

Since the public pays for essentially all physics research, one obvious point of physics outreach is to persuade people to keep the money coming. Fortunately, humans are naturally curious, and the nature of the universe is one of the things people are curious about.

It is probably unfortunate that math is a foreign language to most people, but I don't share your opinion that sprinkling popular science with equations is about to cure that problem.

Jay Poynting said...

Money is tight. Most physics faculty I know spend more time writing grant proposals and managing than doing research. Self-promotion makes it easier to get $$$.

Sabine Hossenfelder said...


Well, most of us live in representative democracies, so the public doesn't get to make that decision directly. In any case, this is of course what I meant when I wrote about the relevance of telling people what it's good for, and that it's necessary for sustainable progress. I actually think when it comes to funding it's less the public that is a problem and more the politicians.

Well, I just disagree with you then on the usefulness of 'sprinkling math'. I think almost everybody can learn to 'read' that foreign language that is math. Whether they ever learn to speak it is another matter entirely. And much of learning a language comes simply due to exposure. Even I learned some Swedish just because I have to look at Swedish words constantly. Think about this for a moment. Differential equations for example aren't really all that difficult to read once you figure out what the symbols mean. Whether you know what to do with these equations is another question entirely. Best,


Sabine Hossenfelder said...

Jay: I doubt this is true, and I think most of my colleagues also doubt it. If they did believe it, then why aren't more of them engaging in public outreach? There is some data demonstrating that public outreach slightly increases the number of citations, but that's pretty much all evidence I know. Best,


JimV said...

I have been frustrated with popular science books that don't include any math. I don't feel I have any real understanding if I don't know the math - which I might not understand anyway, but at least I would know why and what I would have to do (study the math) to gain understanding. When presenting math, though, I think examples should be given. It is easy to misunderstand terminology without examples. All this will make popular science books harder to write, of course.

(Telling myself as I write, I won't beg Dr. Hossenfelder to write a popular science book again - it annoys her.)

JSV said...

Good post. I contributed to a post-conference debate on this in 2008. I'll see if I can dig out my resulting letter. I'll spare you the details by not posting it here - instead, here are the pertinent points of what I remember:

It's important to inspire, but those attempting to 'make a difference' should have enough information to know if their ideas are sufficiently-developed, can work, apply to some of the current science, and include tests of falsifiability.
Critically: (a) there needs to be enough interest to educate the policy-makers to provide funding for further research, (b) we need the gateways that enable people to contribute to their best of their ability.

Too much inspiration (using simplifications) can lead to wasted energy and too much noise, from people who don't really know what they're talking about. There needs to be a better way of lifting the best ideas out of the noise, but the system is not geared towards this arduous process of discovery and filtering.

Presently, that noise problem is (nearly) solved by exclusion and costs, leaving the formal channels of qualifications, affiliations, and so on. But in doing so, some of the signal is lost.

Aside from funding, the problem boils down to the lack of resource for curation and mentoring.

Let's not confuse this with the argument on whether 'foundations' should be researched; that is based on research tending towards predictable outcomes, rather than blue-sky speculation.

Phil Jones said...

"This inspiration-education-gap is sometimes so large that it creates an illusion of knowledge among those only reading the inspirational literature." This illusion is also helped by the availability of knowledge from the internet. It is possible to google the terms being used in current level research discussions ("conformal invariance", "instanton", "NMHV amplitude"....), and be able to relay (sometimes even correct!) statements without really having a clue what you're talking about.

CapitalistImperialistPig said...

The number one review of Weinberg's new popular science book at Amazon includes praise for the author for not assuming that the reader is "one of those mutants who remembers what a cosine is."

Andrew Thomas said...

I absolutely agree that differential equations, or virtually any equation, are not difficult once you figure out what the symbols mean. So many popular science books have that jokey patronising tone, treating readers like dummies. Drives me mad. And don't get me started on Brian "takes an hour to explain something really simple" Cox.

CapitalistImperialistPig said...

There are an increasing number of books which are aimed at those with a modest competence in mathematics - textbooks on particle physics and cosmology not aimed at either specialists or the general public.

However, I don't see a parallel between understanding the fundamental equation of general relativity and some sentence about trucks in Swedish. The sentence about trucks in Swedish has parallels in almost every other language as well as referents in everyday experience. That's not the case for curvature and stress energy tensors.

John Baez said...

I think it's both inspiring and educational to give good explanations of physics that's well-understood to experts but not most people. How can you measure the diameter of the Earth? How can you then use that to measure the distance to the Moon? These are experiments ordinary people can do, made much easier by a touch of modern technology. Eratosthenes had to work to measure the position of the Sun in the sky at two places of different latitude at the same time - with Facebook, Twitter and cell phones it's a lot easier! And the point is, getting people to figure things out for themselves is both fun and a solid step toward doing science. Listening to people talk about quantum mechanics and black holes is not inherently more scientific than listening to myths of gods and heroes around the campfire.

chip said...

Nice article, sounds like an interesting time. I'm a little confused about what's meant by foundations of physics as opposed to...well, just physics research. That is, foundations = Measurement Theory as opposed to the Higgs Boson? Or something different...?

For myself, when I teach in classes or whenever I speak to the public, my perspective is one of being grateful for public support (I always thank them) and offer what I've got to say in the manner of "here's where your money went." Paying back, so to speak. (This has the added effect of being able to note that my university does not pay for me to Europe 5 times a year! But that I have to compete for the funds that allow me to visit my experiment. That's useful outreach I've found, especially given sensitivities about tuition in the US.) Where "paying back" fits on the inspiration-education continuum depends on the audience and the topic. I need to think about that as it's an interesting axis.

BTW, the new Theory That Unifies Everything from Bob's Research Institute, PO Somewhere, South Dakota phenomenon is not an internet-age discovery. We used to get these things in the mail...the paper mail...a few times a year.

nicolas poupart said...

An interesting concept is the development of popular science on several levels either: a text without equation using analogies, the same information but with a text with basic algebra, a text with differential equations and / or base matricial calculus and a final text with the specialized symbolic. Thus the reader can go as far as he wants and build bridges between the different levels of understanding.

I do not know if Brassard was at least a little interesting with its "Local Realistic Theory"; I loved this teacher in the introduction to theoretical computer science at UDM in 90. It seems that you have not appreciated.

P.S. I think you perfectly apply the Dagomir theory in your latest video, you look great, the batik is beautiful.

Rastus Odinga Odinga said...

I know a lot of physicists who won't touch outreach with a ten-foot pole, and the recent flood of examples where people have been using pop-sci to hype their work has only hardened that attitude. I firmly believe that outreach, of any kind, should never focus on the latest research. The reason for the recent catastrophic decline in the standards of New Scientist and Scientific American etc is that their writers have learned how to use the arXiv.

Instead of "latest work of Prof Schlong at Howard Putz University suggests that the Universe will explode soon! see 1504.8888*!" what we really need is people explaining what it really means for the Universe to expand, that redshift isn't a Doppler effect, what entanglement is, what a wormhole might be, etc etc etc. Less sexy women, more talk about things we actually *know* about....

JSV said...

"I think it's both inspiring and educational to give good explanations of physics that's well-understood to experts but not most people." - John Baez, previous comment.

There's something in this: accessibility. When people are interested, there should be material 'at the next level' for them to explore further.

For example, for any given 'profound' paper released in a journal, there will be publicity and journalism. Ideally, this reporting will be tiered on perhaps four levels:

(a) For the few scientists who will readily grasp the paper - a news feed from the publisher/SIG/conf proc. No maths; just look at the paper!

(b) For people who know some physics, usually academics in related fields, or the same institutio - some maths.

(c) For the interested public. Includes references to relevant concepts, uses everyday analogies, but usually has no maths. Speculates on further work.

(d) Mainstream reporting, definitely no maths unless the reporter is trying to blind the reader, usually sensationalizes and mis-reports. Speculates on further disaster.

Sometimes we get this wrong, and distort the message of the original paper by the time it reaches the public. However, the key idea here is to make the science accessible, and to enable people to dig more if they wish. It helps if there's a vertical chain of referencing through these levels (d-a, above).

Uncle Al said...

"making movies with sexy women is the way to better communicate physics" for males. For females, men with wealth and power. "send me their new theory of quantum mechanics" Newton has two defective postulates immune to derivation. Substituting empirical postulates hurts, re Galileo. "It contradicts accepted theory."

" whether we really need more inspiration" Do it the other way. Test spacetime geometry with geometry (chemistry), not composition and field. Boson photons are not fermion quarks - different rules, not perturbations. Visibly white polar bears in snow (difficult) are UV-black (easy). Quantum gravitation must begin empirical not beautiful.

Sabine Hossenfelder said...


Yes, it's a good approach! I don't think though that one size fits all, this will work for some and not for other. Best,


Sabine Hossenfelder said...


No, it doesn't annoy me. But there are only so many hours in the day. As I said, in the end it comes down to the question who does it and who pays for it. Writing popular science books is not something one can live from, sad but true. Best,


Sabine Hossenfelder said...


Yes, I'm with you on that. I think we really shouldn't treat people like they are stupid. It's good if there are really simple explanations, but why stop there? Best,


Sabine Hossenfelder said...


In principle I agree with you, but in practice it's a question of demand and supply. If people want to read about what nonsense has been posted on the arxiv yesterday, then that's what pop sci outlets will write about. I don't think most readers realize that much of what they're being fed in these outlets is nonsense. I don't like that because I can literally see that theoretical physics is dropping to a level where we now have public health advice: on day this is fashionable and must be done, the next day that's wrong and now something new is supposedly correct, so then what do physicists really know? The universities' PR outlets and scientists themselves are willingly playing along.

This is another reason why it would be good to have hard data showing whether a place actually benefits from this procedure. I suspect they don't. The reason is that I can tell in the community this kind of self-promotion has a huge backlash. It is much easier to fly under the radar than to draw scrutiny. Best,


Sabine Hossenfelder said...


In fact, this is the exact same thing that I've been thinking about! Maybe one day if I have the time I'll get serious about it...

I love the batik shirt. Unfortunately it's 20 years old and has several holes and is about to fall apart :( I have to find myself a new one somewhere. Best,


Sabine Hossenfelder said...


Not sure where the trucks came in... Sure, you still need some explanation about what are the things in the equation. What is an equation? It's a collection of mathematical objects related by operations. All you really need is that somebody explains you what these things mean, and in principle you're good to go. I mean, take the Friedmann equations as example. These are really not all that difficult to understand once somebody tells you what these dots mean. Best,


maaneli said...

Hi Sabine,

Thanks for your interesting post. I agree with most of your points. Regarding quantum foundations, as a graduate student in this field, maybe I can offer some answers to your questions.

<< Even I honestly don’t understand the point of much of the research in quantum foundations, so if you needed any indication that public outreach in quantum foundations isn’t working all that well, please take me as a case study. For all I can tell there seem to be a lot of people in this field who spend time reformulating a theory that works perfectly fine, and then make really sure to convince everybody their reformulation does exactly the same as quantum mechanics has always done. >>

My impression is that nobody who works in QM foundations disputes that standard/textbook QM works great for all practical purposes (i.e. for any laboratory experiment one can do). But the existence of the quantum measurement problem (which, incidentally, becomes most egregious in the context of quantum cosmology) implies that standard QM is either an incomplete description of nature or an ultimately incorrect theory of nature. I think it's fair to say that, for most people in QM foundations, this is the most concrete reason for working on either reinterpreting/reformulating quantum theory, reconstructing quantum theory from an underlying theory, or building competitor theories - to find the correct microscopic theory that doesn't suffer from the measurement problem, and makes predictions that agrees with all current experimental constraints (which it of course needs to in order to be considered empirically adequate). It's true that some alternative approaches (e.g. de Broglie-Bohm) will make the same predictions as standard QM for any laboratory experiment one can possibly do (and insofar as standard QM can give a well-defined prediction), but it's not clear that this empirical equivalence will hold in the context of semiclassical/quantum cosmology. Also, some approaches (like the GRW/CSL theories) make slightly different predictions from standard QM in regimes just outside of current experimental constraints, as well as in the context of semiclassical/quantum cosmology. So testable new physics *can* come out of trying to solve the measurement problem.

Another (more philosophical) reason why many people work on alternative approaches is simply because standard QM is considered by many people to be "unprofessionally vague and ambiguous" (to quote an often cited line of John Bell), in regards to the measurement postulates and the standard talk of "operators as observables". The view is that a well-formulated physical theory should make a clear statement about the physical ontology of the world, and should give mathematically precise, observer-independent, dynamical equations for that ontology. Many of the leading alternatives to standard QM (like de Broglie-Bohm and GRW/CSL theories) could be argued to be examples of such well-formulated physical theories.

<< Why, oh why, are they so insistent on finding a theory that is both realist and local >>

I'm curious how you got that impression, because most researchers in QM foundations are actually not insistent on finding a local realist theory. The leading alternative approaches (e.g. de Broglie-Bohm and GRW/CSL theories) have nonlocal dynamics that violate Bell's inequalities while not allowing for superluminal signaling. It's true that proponents of Everett's many worlds interpretation claim it's a Bell-inequality-violating local theory, but my understanding is that that claim is controversial even with the foundations community (and it's still controversial whether or not the Everettian interpretation actually works as claimed). There is also a minority contingent of foundations workers who propose to save locality by constructing theories with retro-causal effects, but that approach is still a work in progress (not to mention also controversial in its viability).

DocG said...

" . . . movies with sexy women . . ."

Hmmmm. For followers of this blog, I'd imagine that one sort of hits home. (Sigh.)

Phillip Helbig said...

"Writing popular science books is not something one can live from, sad but true."

Actually, one can. Not everyone can, of course, but it is possible. Isaac Asimov, for example, made a very good living from it. (He "retired" from his biochemistry professorship after he started making much more by writing.) I'm sure Carl Sagan earned quite a bit. Many active scientists write popular books: Max Tegmark, Martin Rees, John Barrow. I'm sure all earn enough from their books to live on. In some cases, to be sure, they wouldn't sell many popular books if they weren't well known as scientists (Hawking for example), but others would (Brian Cox, maybe) and some, like Asimov and Clarke, weren't active scientists at all for most of their lives.

It's like, say, music. For most people who make music, it remains at best a hobby, some manage to make a living from it and some become quite rich from it.

Sabine Hossenfelder said...


I doubt it. Sure, there are the super-popular exceptions, but you can count them on your fingers. The vast majority, if they can live from it, make extra money with freelancing and public lectures and so on. Best,


claver said...

If the man who invented football was alive, l seriously doubt that he'd be the best player.

Furthermore, l seriously doubt that the first men to play football were much better than those who came after.

Inasmuch, today's modern theorist probably knows more about quantum field theory than Bohr ever did.

The point is that the foundations are often less intricate, less complex than the structure built on top of it.

Furthermore, a new paradigm is built on a new foundation.

tim314 said...

Good post. I wish there were more math in how physics is usually presented to the general public, or at least more acknowledgement of the fact that without the math you're at best being presented with a flawed metaphor.

Regarding why people spend time reformulating a theory that works perfectly well, perhaps the hope is to do what Einstein did for the Lorentz transformations, that is to take a correct result and give it a more sound conceptual underpinning. (Although of course Einstein did far more beyond that.) I guess how much value there is in that depends on how satisfied one is with the current conceptual underpinnings of quantum mechanics.

Alter Erto said...

Lovely post!
Being myself one of those who attempted to drift away from the shores of pop-science into the depths of technical knowledge, I think this problem really needs a good tackle.
You see, I started off really cranky. Imagine that what inspired me to really dive into physics were 3 movies: what the bleep do we know, the secret and mindwalk. Thankfully, I am such a curious person that I was not satisfied with blurbs, headlines and claims: I wanted do read the actual research papers. From that point on it was inevitable, if I was to understand anything, I had to study (there are some really good courses on iTunesU if anyone has the thirst but not the money).
Which brings me to a possible solution to shorten the shore-to-island distance: hypertext.
Wouldn't it be nice if you read a newsflash with links for every term, name, number, piece of data and reference? With two or three clicks (or one), one could end-up at the web version of the original scientific paper itself, which then itself could be all hypertexted with links leading curious people to all sorts of background information (including online courses, books, related research and explanations of technical terms).
That would make the swimming a lot easier, the inspiration a lot more informative and the information a lot easier to grasp. It would all depend on the audience's will to learn and study. As it is now, news articles link to other news articles and sometimes the references are at the end of the text, separated with commas, far away from the exact context with which they are relevant.
And please, no nudity, I really think the sexy approach to science does a real disservice to us all, making it even harder to swim, convincing many of us mortals that black holes are doors between parallel universes, that the observer changes reality with mind control, and that everything between far-fetched hypotheses to bad interpretations and sexy semantics are unquestionable, physical facts, when they are many times just advertising tricks.

William Wallace said...


I represent a typical member of the general public interested in science. After too many years reading popular science, I have finally managed to stop imagining one can manipulate metaphors in the same way one does data. The downside to that is that I have been largely turned off by the prospect of reading more of the same.

I think that blurbs or sidebars in text could provide the "A level" discussion, especially maths, and so allow material to be published with multiple targets in mind. I think this is more practical than publish-time customization.

But the reason I post is to suggest that one gaping whole in most literature on physics is that it starts with current discussion. I could not grasp the 2nd Law of Thermodynamics until I was -finally- exposed to its derivation with respect to steam engines.

I think a lot more of the same would be extraodinarily useful to readers such as myself: start with the historical problem, usually much simpler and better defined, then work that up into its current import.

Not quite history and not quite standard textbook, if physics were taught this way, with ample sidebars for those going on the do the math, I think general readers would gain a much better appreciation. Leave the sexy stuff for the ocassional headliner article to draw interest, but let's put more context in textbooks.

My $0.02. Regards.