My first total eclipse: What I am looking forward to

On April 8th, a total solar eclipse will cast its shadow across Mexico, the United States and Canada. This solar eclipse is quite special for a number of reasons. Let’s have a look at why this solar eclipse is so special and some things you should be on the lookout for.

Public Event in Canada coming up in April

Yes, I have taken traveling back up and optimistically agreed to a public event in Vancouver on April 14, together with Lawrence Krauss and Chris Hadfield. If you're in the area, it would be lovely to see you there! Don't miss the trailer video


Tickets will be on sale from Jan 1st on this website.

The Mathematics of Consciousness

[This is a transcript of the video embedded below.]


Physicists like to think they can explain everything, and that, of course, includes human consciousness. And so in the last few decades they’ve set out to demystify the brain by throwing math at the problem. Last year, I attended a workshop on the mathematics of consciousness in Oxford. Back then, when we still met other people in real life, remember that?

I find it to be a really interesting development that physicists take on consciousness, and so, today I want to talk a little about ideas for how consciousness can be described mathematically, how that’s going so far, and what we can hope to learn from it in the future.

The currently most popular mathematical approach to consciousness is integrated information theory, IIT for short. It was put forward by a neurologist, Giulio Tononi, in two thousand and four.

In IIT, each system is assigned a number, that’s big Phi, which is the “integrated information” and supposedly a measure of consciousness. The better a system is at distributing information while it’s processing the information, the larger Phi. A system that’s fragmented and has many parts that calculate in isolation may process lots of information, but this information is not “integrated”, so Phi is small.

For example, a digital camera has millions of light receptors. It processes large amounts of information. But the parts of the system don’t work much together, so Phi is small. The human brain on the other hand is very well connected and neural impulses constantly travel from one part to another. So Phi is large. At least that’s the idea. But IIT has its problems.

One problem with IIT is that computing Phi is ridiculously time consuming. The calculation requires that you divide up the system which you are evaluating in any possible way and then calculate the connections between the parts. This takes up an enormous amount of computing power. Estimates show that even for the brain of a worm, with only three hundred synapses, calculating Phi would take several billion years. This is why measurements of Phi that have actually been done in the human brain have used incredibly simplified definitions of integrated information.

Do these simplified definitions at least correlate with consciousness? Well, some studies have claimed they do. Then again others have claimed they don’t. The magazine New Scientist for example interviewed Daniel Bor from the University of Cambridge and reports:

“Phi should decrease when you go to sleep or are sedated via a general anesthetic, for instance, but work in Bor’s lab has shown that it doesn’t. “It either goes up or stays the same,” he says.”

I contacted Bor and his group, but they wouldn’t come forward with evidence to back up this claim. I do not actually doubt it’s correct, but I do find it somewhat peculiar they’d make such a statements to a journalist and then not provide evidence for it.

Yet another problem for IIT is, as the computer scientist Scott Aaronson pointed out, that one can think of rather trivial systems, that solve some mathematical problem, which distribute information during the calculation in such a way that Phi becomes very large. This demonstrates that Phi in general says nothing about consciousness, and in my opinion this just kills the idea.

Nevertheless, integrated information theory was much discussed at the Oxford workshop. Another topic that received a lot of attention is the idea by Roger Penrose and Stuart Hamaroff that consciousness arises from quantum effects in the human brain, not in synapses, but in microtubules. What the heck are microtubules? Microtubules are tiny tubes made of proteins that are present in most cells, including neurons. According to Penrose and Hameroff, in the brain these microtubules can enter coherent quantum states, which collapse every once in a while, and consciousness is created in that collapse.

Most physicists, me included, are not terribly excited about this idea because it’s generally hard to create coherent quantum states of fairly large molecules, and it doesn’t help if you put the molecules into a warm and wiggly environment like the human brain. For the Penrose and Hamaroff conjecture to work, the quantum states would have to survive at least a microsecond or so. But the physicist Max Tegmark has estimated that they would last more like a femtosecond, that’s only ten to the minus fifteen seconds.

Penrose and Hameroff are not the only ones who pursue the idea that quantum mechanics has something to do with consciousness. The climate physicist Tim Palmer also thinks there is something to it, though he is more concerned with the origins of creativity specifically than with consciousness in general.

According to Palmer, quantum fluctuations in the human brain create noise, and that noise is essential for human creativity, because it can help us when a deterministic, analytical approach gets stuck. He believes the sensitivity to quantum fluctuations developed in the human brain because that’s the most energy-efficient way of solving problems, but it only becomes possible once you have small and thin neurons, of the types you find in the human brain. Therefore, palmer has argued that low-energy transistors which operate probabilistically rather than deterministically, might help us develop artificial intelligent that’s actually intelligent.

Another talk that I thought was interesting at the Oxford workshop was that by Ramon Erra. One of the leading hypothesis for how cognitive processing works is that it uses the synchronization of neural activity in different regions of the brain to integrate information. But Erra points out that during an epileptic seizure, different parts of the brain are highly synchronized.

In this figure, for example, you see the correlations between the measured activity of hundred fifty or so brain sites. Red is correlated, blue is uncorrelated. On the left is the brain during a normal conscious phase, on the right is a seizure. So, clearly too much synchronization is not a good thing. Erra has therefore proposed that a measure of consciousness could be the entropy in the correlation matrix of the synchronization. Which is low both for highly uncorrelated and highly correlated states, but large in the middle, where you expect consciousness.

However, I worry that this theory has the same problem as integrated information theory, which is that there may be very simple systems that you do not expect to be conscious but that nevertheless score highly on this simple measure of synchronization.

One final talk that I would like to mention is that by Jonathan Mason. He asks us to imagine a stack of compact disks, and a disk player that doesn’t know which order to read out the bits on a compact disk. For the first disk, you then can always find a readout order that will result in a particular bit sequence, that could correspond, for example, to your favorite song.

But if you then use that same readout order for the next disk, you most likely just get noise, which means there is very little information in the signal. So if you have no idea how to read out information from the disks, what would you do? You’d look for a readout process that maximizes the information, or minimizes the entropy, for the readout result for all of the disks. Mason argues that the brain uses a similar principle of entropy minimization to make sense of information.

Personally, I think all of these approaches are way too simple to be correct. In the best case, they’re first steps on a long way. But as they say, every journey starts with a first step, and I certainly hope that in the next decades we will learn more about just what it takes to create consciousness. This might not only allow us to create artificial consciousness and help us tell when patients who can't communicate are conscious, it might also help us allow to make sense of the unconscious part of our thoughts so that we can become more conscious of them.

You can find recordings of all the talks at the workshop, right here on YouTube, please check the info below the video for references.

---

You can join the chat about this video today (Saturday, Jan 9) at noon Eastern Time or 6pm CET here.

Travel and Book Update

My book “Lost in Math” has meanwhile also been translated to Hungarian and Polish. Previous translations have appeared in German, Spanish, Italian, and French, I believe. I have somewhat lost overview. There should have been a Chinese and Romanian translation too, I think, but I’m not sure what happened to these. In case someone spots them, please let me know. The paperback version of the US-Edition is scheduled to appear in June.

My upcoming trips are to Cambridge, UK, for a public debate on the question “How is the scientific method doing?” (on Jan 28th) and a seminar about Superdeterminism (on Jan 29). On Feb 13, I am in Oxford (again) giving a talk about Superfluid Dark Matter (again), but this time at the physics department. On Feb 24th, I am in London for the Researcher to Reader Conference 2020.

On March 9th I am giving a colloq at Brown University. On March 19th I am in Zurich for some kind of panel discussion, details of which I have either forgotten or never knew. On April 8, I am in Gelsenkirchen for a public lecture.

Our Superdeterminism workshop is scheduled for the first week of May (details to come soon). Mid of May I am in Copenhagen for a public lecture. In June I’ll be on Long Island for a conference on peer review organized by the APS.

The easiest way to keep track of my whatabouts and whereabouts is to follow me on Twitter or on Facebook.

Travel Update

The coming days I am in Brussels, for a workshop that I’m not sure where it is or what it is about. It also doesn’t seem to have a website. In any case, I’ll be away, just don’t ask me exactly where or why.

On Oct 15, I am giving a public lecture at the University of Minnesota. On Oct 17, I am giving a colloquium in Cleveland. On Oct 25, I am giving a public lecture in Göttingen (in German). On Oct 29, I’m in Genoa giving a talk at the “Festival della Scienza” to accompany the publication of the Italian translation of my book “Lost in Math.” I don’t speak Italian, so this talk will be in English.

On Nov 5th I’m speaking in Berlin about dark matter. On Nov 6th I am supposed to give a lecture at the Einstein Forum on Potsdam, though that doesn’t seem to be on their website. These two talks in Berlin and Potsdam will also be in German.

On Nov 12th I’m giving a seminar in Oxford, in case Britain still exists at that point. Dec 9th I’m speaking in Wuppertal, details to come, and that will hopefully be the last trip this year.

Next time I’m in the USA will probably be late March 2020. In case you are interested that I stop by at your place, please get in touch.

I am always happy to meet readers of my blog, so in case our paths cross, do not hesitate to say hi.

Away Note

I'm attending a conference in Oxford the coming week, so there won't be much happening on this blog. Also, please be warned that comments may be stuck in the moderation queue longer than usual.

Away Note

I will be away for a week to attend SciFoo 2019. Please expect blogging to be sparse and comments to be stuck in the queue longer than usual.

Away Note

I'll be in the Netherlands for a few days to attend a workshop on "Probabilities in Cosmology". Back next week. Wish you a good Summer Solstice!

Book and travel update

The French translation of my book “Lost in Math” has now appeared under the title “Lost in Maths: Comment la beauté égare la physique”.

The Spanish translation has now also now appeared under the title “Perdidos en las matemáticas: Cómo la belleza confunde a los físicos.” I don’t speak Spanish, but for all I can tell, the title is a literal translation.

On Thursday (May 23rd) I am giving a public lecture in Barcelona. The lecture, it turns out, will be simultaneously translated into Spanish. This, I think, will be an interesting experience.

The next talks I have scheduled are a colloquium in Mainz, Germany, on June 11, and a public lecture in Groningen, Netherlands, on June 21st. The public lecture is associated with the workshop “Probabilities in Cosmology” at the University of Groningen.

I declined the invitation to the Nobel Laureate meeting in Lindau because I was informed they would only cover my travel expenses if I agree in advance to write about their meeting for a 3rd party. (If you get pitches about the meeting, please ask the author for a COI.)

After some back and forth, I accepted the invitation to SciFoo 2019, mostly because I couldn’t think of a way to justify declining it even to myself.

The fall is filling up too. The current plan looks roughly like this: On September 21st, I am giving a public lecture in Nürnberg. Early October I am in Brussels for a workshop. Mid of October I am giving a public lecture at the University of Minnesota. (I have not yet booked the flight for this trip. So if you want me to stop by at your institution for a lecture on the way, please get in touch asap.) End of October I am giving a lecture in Göttingen, and the first week of November I am in Potsdam and, again, in Berlin.

From November on, I will be unemployed, at least that is what it presently looks like. Or maybe I should say I will be fully self-employed. Either way, I will have to think of some other way to earn money than doing calculations in Anti-DeSitter space.

Finally, here is the usual warning that I am traveling for the rest of the week and comments on this blog will be stuck in the moderation queue longer than usual.

Away Note/Travel Update/Interna

I will be away next week, giving three talks at Brookhaven National Lab on Tuesday, April 9, and one at Yale April 10.

Next upcoming lectures are Stuttgart on April 29 (in Deutsch), Barcelona on May 23, Mainz on June 11, (probably) Groningen on June 22, and Hamburg on July 5th.

I may or may not attend this year’s Lindau Nobel Laureate meeting, and have a hard time making up my mind about whether or not to go to SciFoo, because, considering the status of my joints, it’s a choice between physical and financial pain, and frankly I’d rather chose neither.

In any case, I am always happy to meet readers of my blog, so if our paths should cross, please do not hesitate to say Hi.

It follows the obligatory note about slow traffic on this blog while I am traveling: I have comment moderation on. This means comments will only appear after I have manually approve them. Sometimes I sleep, sometimes I am offline, sometimes I have better things to do than checking my inbox. As a result, comments may sit in the queue for a while. Normally it does not take longer than 24 hours.

Let me also mention that I no longer read comments posted as “Unknown”. I have no idea what Google is doing, but the “Unknown” comments are today what anonymous comments were a decade ago. The vast majority of those are spam, and most of the rest are insults and other ill-informed nonsense. I do not have time for this and therefore collectively forwarded them straight to junk.

There have also recently been some (?) people who tried to post random strings of letters or, in some cases, single letters. I am assuming this was to try if the comment feature works. I will not approve such comments, so it is not a useful method to figure out what is going on.

You say theoretical physicists are doing their job all wrong. Don’t you doubt yourself?

This is me with John Horgan, yesterday.
This photo is only here so
the share widgets work properly.

One of the most frequent critical remarks I have gotten on my book is that I seem confident. I was supposed, it seems, to begin each paragraph with “I’m sorry, but.”

But I am not sorry. I mean what I say. Yes, in the foundations of physics we are financing some 15,000 or so theorists who keep producing useless scientific articles because they believe the laws of nature must be beautiful. That’s exactly what I am saying.

Let us leave aside for a moment that you have to skip half the book to not notice I question myself on every other page. Heck, if you ask me to sign the book, I’m afraid I’ll misspell my own name. I’m a walking-talking bag of self-doubt. Indeed that was the reason I ended up writing this book.

See, I don’t understand what’s going on with this community. Everyone knows there’s no reason that a scientific explanation must appeal to the human sense of beauty. Right? Doesn’t everyone know this? Science is about explaining observations, regardless of whether we like these explanations.

But if it’s clear that putting forward new hypotheses just because they are beautiful doesn’t mean they’re likely to be right, then why do theorists in these fields focus so much on beauty? Worse, why do they continue to focus on the same type of beauty, even though that method has demonstrably not worked for 40 years?

At first I considered there might be a mathematical basis to their arguments which I was missing. That there is a solid reason why a theory must be natural, or that the fundamental forces must be unified, or that the mathematics of a theory must be “fruitful” and “have deep connections” and be “rigid” – to quote some expressions people in the foundations of physics commonly use. But there is no mathematical basis. Arguments from beauty are additional assumptions, and they are unnecessary to make a theory work.

Indeed, some philosophers have suggested I speak of “metaphysical assumptions” rather than “aesthetic arguments”, but I think the latter captures the historical origin better. These arguments trace back to tales about God’s beautiful creations. Also, if I’d call it metaphysics no one would know what I am talking about.

I then considered that using criteria from beauty is justified because it has historically been successful. This would leave open the question why that would be so – I cannot think of a reason such a connection should exist. But in any case, history speaks against it. Relying on beauty has sometimes worked, and sometimes not. It’s just that many theoretical physicists prefer to recall only the cases where arguments from beauty did work. And in hindsight they then reason that the wrong ideas were not all that beautiful. Needless to say, that’s not a good way to evaluate evidence.

Finally, the use of criteria from beauty in the foundations of physics is, as a matter of fact, not working. Beautiful theories have been ruled out in the hundreds, theories about unified forces and new particles and additional symmetries and other universes. All these theories were wrong, wrong, wrong. Relying on beauty is clearly not a successful strategy.

So I have historical evidence, math, and data. In my book I lay out these points and tell the reader what conclusion I have drawn: Beauty is not a good guide to theory-development.

I then explain that this widespread use of scientifically questionable but productive methodology is symptomatic to the current organization of academic research, and a problem that’s not confined to physics.

Now, look, just because I cannot find a reason that beautiful theories are more promising than ugly ones doesn’t mean that relying on beauty cannot work. It may work, if we get lucky. Neither, for that matter, do I think that if we find a new law of nature it must be ugly. Chances are we will come to find a successful new idea beautiful simply because it works. But our sense of beauty changes and adapts, and therefore I do not think that using criteria of beauty from the past is a promising route to future progress.

Needless to say, making a case against a community of some thousands of the biggest brains on the planet has not been conducive to my self-confidence. But I have tried to find a scientific reason for the methods which my colleagues use in theory-development and could not. I wrote the book because I think it’s my responsibility as scientist to say clearly that I have come to the conclusion what goes on the foundations of physics is a waste of money, and that the public is being misinformed about the promise of this work.

I do not think that this will change the mind of people in the field. They have nothing to worry about because the way that academia is currently organized there is safety in numbers.

So, yes, I doubt myself. But I have written a whole book in which I explain why I have arrived at my conclusion. Rather than asking me, you should ask the people who work in these fields what makes them so certain that beautiful ideas are promising descriptions of nature.

Das hässliche Universum [book & travel update]

[See below for travel update in English]

Ab heute ist die Deutsche Übersetzung von „Lost in Math“ in Handel erhältlich unter dem Titel „Das hässliche Universum: Warum unsere Suche nach Schönheit die Physik in die Sackgasse führt.“ Wegen Kommunikationsproblemen mit dem Verlag habe ich die Deutsche Übersetzung nicht im voraus gesehen; tatsächlich habe ich das Buch selbst erst am Freitag erhalten. Ich hab’s bisher auch nicht gelesen. Lasst mich doch bitte wissen, was drin steht.

Ich werde auch in den nächsten Monaten noch Vorträge zum Thema „Mist in der Physik“ geben, sowohl in Deutsch als auch in Englisch. In der ersten Oktoberwoche bin ich in New Jersey (3. Oktober) und in Richmond, Kentucky (4. Oktober). In der zweiten Oktoberwoche bin ich auf der Buchmesse. Am 7. November gebe ich einen Vortrag am Planetarium „Am Insulaner“ in Berlin (und zwar nicht über das Buch sondern über Dunkle Materie). Am 8. November rede ich in der Urania, dann wieder über mein Buch. Am 29. November bin ich an der Chapman University, Los Angeles, und am 10. Dezember in Kaiserslautern. 

Ausser der Deutschen Übersetzung wird es ausserdem Übersetzungen geben in Chinesisch, Japanisch, Spanisch, Französisch, Russisch, Koreanisch, Italienisch und Rumänisch.

On October 3rd I’m New Jersey at the Stevens Institute for Technology. I can’t recall sending either title or abstract, but evidently I’m speaking about “How Physics Went Wrong.” On October 4th I’m in Richmond, Kentucky, for a lecture and book signing.

The week after this I’m in Frankfurt on the International Book Fair. On November 7th I’m speaking at the Berlin observatory “Am Insulaner” about dark matter (not about the book!) and on November 8th I’m at the Urania in Berlin, back to speaking about the book. On November 29th I’m at Chapman University LA, on December 10th in Kaiserslautern, Germany.

Besides German, the book will also be translated to Chinese, Japanese, Spanish, Italian, French, Russian, Korean, and Romanian. The English audiobook is supposed to appear in December. The British, you guessed it, still haven’t bought the rights.

For updates, please follow me on twitter or facebook.

Away Note

I’ll be traveling the next two weeks. First I am in Santa Fe, giving both a colloquium and a public lecture, and then I am in Oslo, giving two talks, one at the Kavli Symposium and one at the public library.

Later in September I’ll be in London at HowTheLightGetsIn. The first week of October, I’ll be in NYC and afterwards in Lexington, Kentucky. The week after that I’ll be at the international book fair in Frankfurt, and in early November I’ll be in Berlin (details to come).

I have been advised that giving talks about my book is private business, so please note that the next two weeks I am officially on vacation for the first time since 2008 (which was our two-years-late honeymoon trip).

Vacation or not, it is foreseeable that I will be offline for extended periods, so please prepare for a slow time on this blog.

What's the purpose of working in the foundations of physics?

That’s me. Photo by George Musser.
Yes, I need a haircut.

[Several people asked me for a transcript of my intro speech that I gave yesterday in Utrecht at the 19th UK and European conference on foundations of physics. So here it is.]

Thank you very much for the invitation to this 19th UK and European conference on Foundations of physics.

The topic of this conference combines everything that I am interested in, and I have seen the organizers have done an awesome job lining up the program. From locality and non-locality to causality, the past hypothesis, determinism, indeterminism, and irreversibility, the arrow of time and presentism, symmetries, naturalness and finetuning, and, of course, everyone’s favorites: black holes and the multiverse.

This is sure to be a fun event. But working in the foundations of physics is not always easy.

When I write a grant proposal, inevitably I will get to the part in which I have to explain the purpose of my work. My first reaction to this is always: What’s the purpose of anything anyway?

My second thought is. Why do only scientists get this question? Why doesn’t anyone ask Gucci what’s the purpose of the Spring collection? Or Ed Sheeran what’s the purpose of singing about your ex-lover? Or Ronaldo what’s the purpose of running after a leather ball and trying to kick it into a net?

Well, you might say, the purpose is that people like to buy it, hear it, watch it. But what’s the purpose of that? Well, it makes their lives better. And what’s the purpose of that?

If you go down the rabbit hole, you find that whenever you ask for purpose you end up asking what’s the purpose of life. And to that, not even scientists have an answer.

Sometimes I therefore think maybe that’s why they ask us to explain the purpose of our work. Just to remind us that science doesn’t have answers to everything.

But then we all know that the purpose of the purpose section in a grant proposal is not to actually explain the purpose of what you do. It is to explain how your work contributes to what other people think its purpose should be. And that often means applications and new technology. It means something you can build, or sell, or put under the Christmas tree.

I am sure I am not the only one here who has struggled to explain the purpose of work in the foundations of physics. I therefore want to share with you an observation that I have made during more than a decade of public outreach: No one from the public ever asks this question. It comes from funding bodies and politicians exclusively.

Everyone else understands just fine what’s the purpose of trying to describe space and time and matter, and the laws they are governed by. The purpose is to understand. These laws describe our universe; they describe us. We want to know how they work.

Seeking this knowledge is the purpose of our work. And, if you collect it in a book, you can even put it under a Christmas tree.

So I think we should not be too apologetic about what we are doing. We are not the only ones who care about the questions we are trying to answer. A lot of people want to understand how the universe works. Because understanding makes their lives better. Whatever is the purpose of that.

But I must add that through my children I have rediscovered the joys of materialism. Kids these days have the most amazing toys. They have tablets that take videos – by voice control. They have toy helicopters – that actually fly. They have glittery slime that glows in the dark.

So, stuff is definitely fun. Let me say some words on applications of the foundations of physics.

In contrast to most people who work in the field – and probably most of you – I do not think that whatever new we will discover in the foundations will remain pure knowledge, detached from technology. The reason is that I believe we are missing something big about the way that quantum theory cooperates with space and time.

And if we solve this problem, it will lead to new insights about quantum mechanics, the theory behind all our fancy new electronic gadgets. I believe the impact will be substantial.

You don’t have to believe me on this.

I hope you will believe me, though, when I say that this conference gathers some of the brightest minds on the planet and tackles some of the biggest questions we know.

I wish all of you an interesting and successful meeting.

Away Note

I’ll be in Utrecht next week for the 19th UK and European Conference on Foundations of Physics. August 28th I’ll be in Santa Fe, September 6th in Oslo, September 22nd I’ll be in London for another installment of the HowTheLightGetsIn Festival.

I have been educated that this festival derives its name from Leonard Cohen’s song “Anthem” which features the lines

“Ring the bells that still can ring
Forget your perfect offering
There is a crack in everything
That’s how the light gets in.”

If you have read my book, the crack metaphor may ring a bell. If you haven’t, you should.

October 3rd I’m in NYC, October 4th I’m in Richmond, Kentucky, and the second week of October I am at the International Book Fair in Frankfurt.

In case our paths cross, please say “Hi” – I’m always happy to meet readers irl.

Interna

I am giving (another) seminar in Heidelberg on Wednesday (April 25th), this time about my upcoming book.

May 1st is a national holiday in Germany (labor day) and I’ll be off-grid due to family affairs for some days.

May 7th to 9th I am in Stockholm to get yelled at (it’s complicated).

On May 26th I am in Hay-on-Wye which is a village someplace UK that hosts an event called How The Light Gets In at which I am supposed to debate how “the pursuit of beauty drive[s] the evils that hold back a better society.” I wouldn’t go as far as calling grand unification an evil, so please don’t judge me by the tagline.

I have also been asked to share this image below. Hope it makes more sense to you than to me.

On May 28th I am giving a public lecture in Dublin at the Irish Quantum Foundations conference.

In summary this means May will be a very slow month on this blog.

Who is crazy now? (In which I am stunned to encounter people who agree with me that naturalness is nonsense.)

Natural?

I have new front teeth. Or rather, I have a new dentist who looked at the fixes and patches his colleagues left and said they’ve got to go. Time for crowns. Welcome to middle age.

After several hours of unpleasant short-range interactions with various drills, he puts on the crowns and hands me a mirror. “Have a look,” he says. “They’re tilted,” I say. He frowns, then asks me to turn my head this way and that way. “Open your mouth,” he says, “Close. Open.” He grabs my temples with a pair of tongs and holds a ruler to my nose. Then he calls the guy from the lab.

The lab guy shakes my hand. “What’s up?” he asks. “They crowns are tilted,” I say. He stares into my mouth. “They’re not,” he declares and explains he made them personally from several impressions and angle measurements and photos. He uses complicated words that I can’t parse. He calls for his lab mate, who confirms that the crowns are perfectly straight. It’s not the crowns, they say, it’s my face. My nose, I am told, isn’t in the middle between my pupils. I look into the mirror again, thinking “what-the-fuck,” saying “they’re tilted.”

Now three guys are staring at my teeth. “They’re not tilted,” one of them repeats. “Well,” I try a different take “They don’t have the same angle as they used to.” “Then they were tilted before,” one of them concludes. I contemplate the possibility that my teeth were misaligned all my life but no one ever told me. It seems very possible. Then again, if no one told me so far chances are no one ever will. “They’re tilted,” I insist.

The dentist still frowns. He calls for a colleague who appears promptly but clearly dismayed that her work routine was interrupted. I imagine a patient left behind, tubes and instruments hanging out of the mouth. “Smile,” she orders. I do. “Yes, tilted,” she speaks, turns around and leaves.

For a moment there, I felt like the participants in Asch’s famous 1951 experiment. Asch assigned volunteers to join a group of seven. The group was tasked with evaluations of simple images which they were told were vision tests. The volunteers did not know that the other members of the group had been given instructions to every once in a while all judge a longer of two lines as the shorter one, though the answer was clearly wrong. 75 percent of the trial participants went with the wrong majority opinion at least once.

I’d like to think if you’d put me among people who insisted the shorter line is the longer one, I’d agree with them too. I also wouldn’t drink the water, keep my back to the wall, and leave the room slowly while mumbling “Yes, you are right, yes, I see it clearly now.”

In reality, I’d probably conclude I’m crazy and then go write a book about it. Because that’s pretty much what happened.

For more than a decade I’ve tried to find out why so many high energy physicists believe that “natural” theories are more likely to be correct. “Naturalness,” here, is mathematical property of theories which physicists use to predict new particles or other observable consequences. Particle physicists’ widespread conviction that natural theories were preferable was the reason so many of them thought the Large Hadron Collider would see something new besides the Higgs boson: Supersymmetry, dark matter, extra dimensions, black holes, gravitons, or other exotic things.

Whenever I confessed to one of my colleagues I am skeptical that naturalness is a reliable guide, I was met with a combination of amusement and consternation. Most were nice. They explained things to me that I already knew. They didn’t answer my questions but insisted they did. Some gave up and walked away. Others got annoyed. Every once in a while someone told me I’m just stupid. All of them ignored me.

After each conversation I went and looked again at the papers and lecture notes and textbooks, but each time I arrived at the same conclusion, that naturalness is an argument from beauty, based on experience but with scant empirical evidence. For all I could tell, that a theory be natural was a wish not a prediction. I failed to see a reason for the LHC to honor this wish.

And it didn’t. The predictions for the LHC that were based on naturalness arguments did not come true. At least not so far, and we are nearing the end of new data. Gian-Francesco Giudice, head of the CERN theory division, recently rang in the post-naturalness era. Confusion reigns among particle physicists.

A few months have passed since Giudice’s paper. I am sitting at a conference in Aachen on naturalness and finetuning where I am scheduled to give my speech about how naturalness is a criterion of beauty, as prone to error as criteria of beauty have always been in the history of science. It’s a talk usually met with  befuddlement. Questions I get are mostly alterations of “Did you really just say what I thought you said?”

But this time it’s different. One day into the conference I notice that all I was about to say has already been said. The meeting, it seems, collected the world’s naturalness skeptics, a group of likeminded people I didn’t know exists. And they are getting more numerous by the day.

Most here agree that naturalness is not a reliable guide but a treacherous one, one that looks like it works until suddenly it doesn’t. And though we don’t agree on the reason why this guide failed just now and what to do about it, I’m not the crazy one any more. Several say they are looking forward to reading my book.

The crowns went back to the lab. Attempts at fixing them failed, and the lab remade them entirely. They’re straight now, and I am no longer afraid that smiling will reveal the holes between my teeth.

Away Note

I am overseas the coming week, giving a seminar at Perimeter Institute on Tuesday, a colloq in Toronto on Wednesday, and on Thursday I am scheduled to “make sense of mind-blowing physics” with Natalie Wolchover in New York. The latter event, I am told, has a live webcast starting at 6:30 pm Eastern, so dial in if you fancy seeing my new haircut. (Short again.)

Please be warned that things on this blog will go very slowly while I am away. On this occasion I want to remind you that I have comment moderation turned on. This means comments will not appear until I manually approve them. I usually check the queue at least once per day.

(The above image is the announcement for the New York event. Find the seven layout blunders.)

Stephen Hawking’s 75th Birthday Conference: Impressions

I’m back from Cambridge, where I attended the conference “Gravity and Black Holes” in honor of Stephen Hawking’s 75th birthday.

First things first, the image on the conference poster, website, banner, etc is not a psychedelic banana, but gravitational wave emission in a black hole merger. It’s a still from a numerical simulation done by a Cambridge group that you can watch in full on YouTube.

What do gravitational waves have to do with Stephen Hawking? More than you might think.

Stephen Hawking, together with Gary Gibbons, wrote one of the first papers on the analysis of gravitational wave signals. That was in 1971, briefly after gravitational waves were first “discovered” by Joseph Weber. Weber’s detection was never confirmed by other groups. I don’t think anybody knows just what he measured, but whatever it was, it clearly wasn’t gravitational waves. Also Hawking’s – now famous – area theorem stemmed from this interest in gravitational waves, which is why the paper is titled “Gravitational Radiation from Colliding Black Holes.”

Second things second, the conference launched on Sunday with a public symposium, featuring not only Hawking himself but also Brian Cox, Gabriela Gonzalez, and Martin Rees. I didn’t attend because usually nothing of interest happens at these events. I think it was recorded, but haven’t seen the recording online yet – will update if it becomes available.

Gabriela Gonzalez was spokesperson of the LIGO collaboration when the first (real) gravitational wave detection was announced, so you have almost certainly seen her. She also gave a talk at the conference on Tuesday. LIGO’s second run is almost done now, and will finish in August. Then it’s time for the next schedule upgrade. Maximal design sensitivity isn’t expected to be reached until 2020. Above all, in the coming years, we’ll almost certainly see much better statistics and smaller error bars.

The supposed correlations in the LIGO noise were worth a joke by the session’s chairman, and I had the pleasure of talking to another member of the LIGO collaboration who recognized me as the person who wrote that upsetting Forbes piece. I clearly made some new friends there^^. I’d have some more to say about this, but will postpone this to another time.

Back to the conference. Monday began with several talks on inflation, most of which were rather basic overviews, so really not much new to report. Slava Mukhanov delivered a very Russian presentation, complaining about people who complain that inflation isn’t science. Andrei Linde then spoke about attractors in inflation, something I’ve been looking into recently, so this came in handy.

Monday afternoon, we had Jim Hartle speaking about the No-Boundary proposal – he was not at all impressed by Neil Turok et al’s recent criticism – and Raffael Bousso about the ever-tightening links between general relativity and quantum field theory. Raffael’s was the probably most technical talk of the meeting. His strikes me as a research program that will still run in the next century. There’s much to learn and we’ve barely just begun.

On Tuesday, besides the already mentioned LIGO talk, there were a few other talks about numerical general relativity – informative but also somehow unexciting. In the afternoon, Ted Jacobson spoke about fluid analogies for gravity (which I wrote about here), and Jeff Steinhauer reported on his (still somewhat controversial) measurement of entanglement in the Hawking radiation of such a fluid analogy (which I wrote about here.)

Wednesday began with a rather obscure talk about how to shove information through wormholes in AdS/CFT that I am afraid might have been somehow linked to ER=EPR, but I missed the first half so not sure. Gary Gibbons then delivered a spirited account of gravitational memory, though it didn’t become clear to me if it’s of practical relevance.

Next, Andy Strominger spoke about infrared divergences in QED. Hearing him speak, the whole business of using soft gravitons to solve the information loss problem suddenly made a lot of sense! Unfortunately I immediately forgot why it made sense, but I promise to do more reading on that.

Finally, Gary Horowitz spoke about all the things that string theorists know and don’t know about black hole microstates, which I’d sum up with they know less than I thought they do.

Stephen Hawking attended some of the talks, but didn’t say anything, except for a garbled sentence that seems to have played back by accident and stumped Ted Jacobson.

All together, it was a very interesting and fun meeting, and also a good opportunity to have coffee with friends both old and new. Besides food for thought, I also brought back a conference bag, a matching pen, and a sinus infection which I blame on the air conditioning in the lecture hall.

Now I have a short break to assemble my slides for next week’s conference and then I’m off to the airport again.

Away Note

I’ll be traveling the next two weeks. First to Cambridge to celebrate Stephen Hawking’s 75th birthday (which was in January), then in Trieste for a conference on “Probing the spacetime fabric: from concepts to phenomenology.”  Rant coming up later today, but after that please prepare for a slow time.