Category Archives: Self-referential

Announcing a new newsletter on mechanizing mathematics

I have finally got around to creating a newsletter, tentatively entitled Silicon Reckoner, to be published on Substack. This will be a continuation of the recurring discussion on this blog of the implications of projects to mechanize mathematics, for example in this post or this post.

You can read more about the goals of the newsletter below, in excerpts from the first entry. There will be no additions to the MWA blog (the blog you are now reading) for the foreseeable future. However, at least at the outset I plan not to allow comments on Substack; instead, the comments section of this post will be reserved for discussion of the newsletter. As always, I will decide whether or not to approve comments. This is a form of censorship but the purpose is not to exclude (legitimate) points of view but to keep control of the amount of time I spend on this part of my agenda.

I don’t expect to set up paid subscriptions on Substack, but that may change at some point.

And the disclaimer, to appear in the first newsletter entry:

I will not claim familiarity with any of the formal systems used in the design of automated proof checkers, nor to understand any of the software that implements the actual automatic verification, much less to understand the details of current or future work on AI, whether or not it is applied to mathematics.  Even when I have a pretty good idea of what is going on with some of these systems, I will fiercely deny any technical understanding whatsoever, because my understanding of the technicalities should never be an issue. 

Here, then, is what Silicon Reckoner will be about:

Is artificial intelligence on track to meet the expectations of its investors, who just in 2020 poured $50 billion into the industry?  AI’s record of missed deadlines for predicted milestones is as old as its name.  But literary production on the subject could hardly be more extensive.  Reading all the non-technical books on my local bookstore’s AI shelf would be more than a full-time job, leaving less than no time for my real job, which AI has not yet eliminated.  Even the sub- or parallel discipline of AI ethics now occupies 10 pages of footnotes on the English-language Wikipedia page and 1400 pages published in the last two years by Oxford University Press, on my own bookshelf; practically every day I discover another 100 pages or so.   I have nevertheless forced myself to dip into a representative sample as preparation for an experiment that is beginning to take shape with this text. 

Most of what I’ve read tries to address the question of just how “intelligent” the products of this industry have been up to now, or will be in the near future, or what it would take for actually existing AI to deserve to be called “intelligent,” or whether it would be a good thing, or whether it’s even possible.  None of these is my problem.  Or rather, they are my problem, but only as a citizen of my country, or of borderless civilization, concerned, like everyone else, by what the massive implementation of ostensibly intelligent artificial systems would entail for what matters to me — not least, whether it would make sense for these things to continue to matter to me, or perhaps more accurately whether what matters to me would still matter to anyone or anything else, if the ambitions of AI’s promoters even minimally come to fruition.…

My motivation in undertaking this experiment is to understand the consequences of this way of thinking for my own vocation of pure mathematics, which is marginal to the concerns of most of those at risk of the AI project’s collateral damage but which has been central to the project’s imagination and its aspirations from the very outset. 

It is possible to view the growing interest in automated proof verification and artificial theorem proving, two aspects of a still largely hypothetical AI future of mathematics, as stemming from purely internal factors that govern the profession’s development as it evolves to meet its autonomously defined goals.  The ideal of incontrovertible proof has been bound up with mechanization since it was first articulated, and the logic that ultimately made digital computers possible is a direct outgrowth of the attempt to perfect this ideal in the development of symbolic and philosophical logic in the late 19th and early 20th century, and can even be seen as a byproduct of the proof of the absolute impossibility of realizing this ideal.  I don’t think this view is plausible, given the saturation of our culture with AI themes and memes, that goes well beyond bookstores’ overloaded AI shelves.… 

This post is meant to be the first of a series of texts exploring the reasons for the absence of any sustained discussion of these issues on the part of mathematicians, in contrast to the very visible public debate about the perils and promises of AI.  Much of my book Mathematics without Apologies was devoted to a critique of claims regarding the “usefulness” of mathematics when, as is nearly always the case, they are not accompanied by close examination of the perspectives in which an application of mathematics may or may not be seen as “useful.”  Similarity with the intended critique of the uncritical use of words (like “progress”) that accompany the ideology surrounding mechanization — mechanical proof verification and automated theorem proving, in particular — will be apparent.  The reason should be obvious:  unless we can conceive an alternative to conventional measures of utility for which human mathematics is a positive good, the forces that make decisions about this sort of thing will declare my vocation obsolete.  Most of my colleagues who are involved in advancing the mechanization program have conceded the rhetorical battle and some are already forecasting the demise of human mathematics.  So the plan is to continue the discussion in this new format, and gradually to phase out the blog that I launched when Mathematics without Apologies was published, as I have already tried and failed to do once before. 

Because I will be forced to draw on so many different disciplinary perspectives in the course of exploring the topic of mechanization, there is a real danger that these texts will lose any chance of forming a coherent whole.  For my own sake, then, as much as for the sake of potential readers, I propose a slogan that is meant to hold everything together until I come up with a better slogan.  Here it is: 

Current trends in mechanization belong to the history of mathematics, both as events in a historical process and in the creation of common narratives about the meaning of the process. …

Whom shall we cancel?

MbembeSo much virtual ink has been virtually spilled over a letter in Harper’s, signed by intellectuals and authors and public figures with an unlikely range of political orientations, but united by opposition to “a new set of moral attitudes and political commitments that tend to weaken our norms of open debate and toleration of differences in favor of ideological conformity” — what the media call “cancel culture” — that it’s time to ask whether the history of mathematics also contains episodes or individuals we might want to consider cancelling.  A ripe candidate for cancellation is Oswald Teichmüller, who explained in the fall of 1933 why he organized a boycott of Edmund Landau’s lectures, after the Nazis came to power earlier that year:

Through yesterday’s action a completely new situation has now been created. In order to restore peace in our institute it is necessary, above all, to clear up the fundamentals behind it. You spoke of your belief that what happened yesterday was an anti-Semitic demonstration. My standpoint was, and continues to be, that an anti-Jewish individual action might rather be directed against everyone else than against you. I am not concerned with making difficulties for you as a Jew, but only with protecting – above all – German students of the second semester from being taught differential and integral calculus by a teacher of a race quite foreign to them. I, like everyone else, do not doubt your ability to instruct suitable students of whatever origin in the purely abstract aspects of mathematics. But I know that many academic courses, especially the differential and integral calculus, have at the same time educative value, inducting the pupil not only to a conceptual world but also to a different frame of mind. But since the latter depends very substantially on the racial composition of the individual, it follows that an Aryan student should not be allowed to be trained by a Jewish teacher.

What I find troubling is not so much that courses on “Teichmüller theory” are being taught in Bonn — practically every year, apparently — but that this year, in the very same state of Nordrhein-Westfalen (NRW), an otherwise little-known member of the Landtag for the Free Democratic Party named Lorenz Deutsch called for cancellation of  the invitation of the philosopher and political theorist Achille Mbembe (pictured above) to give the opening speech at the Ruhr Trienniale arts festival.  Deutsch accused Mbembe of antisemitism for having signed a South African BDS petition, and of “relativizing” the Holocaust, rather than recognizing its Einzigartigkeit.    What began as a provinzielles politisches Hickhack, in the words of Deutsche Welle, turned into “Causa Mbembe,” the dominant theme in the spring’s German social debate (“beyond” Coronavirus, again according to Deutsche Welle) in which the full resources and richly polysyllabic vocabulary of German speculative philosophy were brought to bear on a handful of marginal passages in Mbembe’s collected works, both in support of and in opposition to their author.  The multiple ironies of the debate were not lost on the 700 African intellectuals whose open letter to German Chancellor Angela Merkel and President Frank Walter Steinmeier recalled Germany’s own bloody history as a colonial power (Mbembe’s native Cameroon was for a time a German colony).

Soon after “Causa Mbembe” began, the Ruhr Triennale was cancelled, ostensibly because of Coronavirus, although the festival’s director had offered to maintain the event in another form; Mbembe’s speech was cancelled along with it.  That this decision was part of a pattern of cancellations of intellectuals and artists, whose positions on the Boycott, Divestment, and Sanctions movement were considered out of bounds for German public discourse, was noted in a letter signed by 426 artists and intellectuals, but the Harper’s letter ignored this state-sponsored version of “cancel culture.”

But to return to mathematics, how would we go about cancelling Teichmüller (and Ernst Witt, and Ludwig Bieberbach, just for starters)?  We could rename Teichmüller spaces after a prominent victim of the Nazis — Anne Frank, for example — or after Landau himself.   Colleagues who object that neither Frank nor Landau had anything to do with Teichmüller spaces (or Witt vectors, or the Bieberbach Conjecture) can be referred to Stigler’s law of eponymy — which is applicable well beyond mathematics:  Medici didn’t design the Medici Chapels, Rockefeller didn’t build Rockefeller Center, Saint John the Divine didn’t build his Cathedral…

The whole tradition of assigning names to things in mathematics is totally out of control and always has been; mathematics has no central naming authority comparable to the Internet Corporation for Assigned Names and Numbers, although names of theorems and mathematical structures undoubtedly have a longer half-life than domain names on the internet.  Whether or not we eventually choose to embark on a full-scale iconoclastic renaming campaign — and to run the risk that we will soon find reason to regret our choices once again — it would be wise to remember that our profession’s patron saints were not only flawed human beings but that, in many cases, benefiting from racism was among their flaws.  Thus Science magazine pointed out just over a year ago that Isaac Newton’s theory of gravitation was developed with the help of figures “from French slave ports in Martinique,”  and reminds us that the Royal Society “invested in slaving companies,” as did many of my own university’s early benefactors.   (Leibniz, on the other hand, did once develop the argument that chattel slavery is morally impermissible.)

Gaspard Monge, who participated in Napoleon’s expedition to Egypt — the first modern European attempt to dominate the Middle East — had been the Minister of the Colonies under the Girondin government; at no point in his career did he allude to the Sainte-Domingue slave revolt of 1792, the main event that took place while he was Minister, and there is no indication that he protested when Napoleon reestablished slavery in 1802.  A bit later we have the case of Charles Dupin, remembered as a politician rather than a mathematician, but still a member of the Académie des Sciences and sufficiently concerned with mathematics to have managed to get Legendre’s pension restored. If he is indeed remembered as a “liberal” politician it was for his defense of slavery, “with the help of statistics”:

Il est l’auteur, en 1838, d’une brochure intitulée Défense des intérêts coloniaux confiés au Conseil des délégués pendant la législature de 1833 à 1838 dans laquelle il vante la situation des esclaves dans les colonies françaises en l’opposant au sort des Noirs libres des colonies anglaises, en présentant, à grand renfort de statistiques, une moindre mortalité infantile chez ceux qu’il appelle les « non-libres » pour ne pas avoir à utiliser le terme « esclave », ce qui est, selon lui, une « nouvelle preuve de la douceur et des bons soins que les maîtres prodiguent aux mères ainsi qu’à leurs enfants esclaves.

It makes no sense to say that Dupin’s ideas were in the spirit of the times; Condorcet had already refuted them 50 years earlier, in his Réflexions sur l’esclavage des nègres.  Even if Condorcet’s proposal, that would have fully eliminated slavery only after 70 years, is hardly compatible with current values, I would think twice before voting to cancel this particular mathematician, whose statue in Paris was already cancelled to provide metal for the Nazi war effort.

There is a substantial literature on the behavior of mathematicians and their institutions in Nazi Germany (see Michèle Audin’s review  of the book by Reinhard Siegmund-Schulze, and the references at the end).  When a comparable study of the role of mathematics and mathematicians with regard to slavery and colonialism is available, we can ask the question raised in the Science article mentioned above:

Now that the link between early science and slavery has come to light, an important question remains: What should scientists do about it?

The article continues:

Historians say acknowledgment is a start…

Mathematics, music, philosophy, and Alain Badiou


Panel at IRCAM, June 7, 2019.  Left to right:  François Nicolas, Yves André, Fernando Zalamea.  Alain Badiou is seated in the audience on the left.

To celebrate the publication of the third and final volume of Alain Badiou’s Being and Event trilogy, the organizers of the Paris MAMUPHI seminar — MAthématiques, MUsique, PHIlosophie — devoted a two-day conference at IRCAM (Institut de Recherche et Coordination Acoustique/Musique), under the title L’hypothèse du contemporain.

For the 20th anniversary of the Mamuphi seminar (mathematics-music-philosophy), these encounters are dedicated to L’Immanence des vérités, the latest work by the philosopher Alain Badiou, and, more particularly, to his theory of “works-in-truth”. How are works distinguished from “waste” and, incidentally, “archives”? The final part of the work by Badiou formalizes a limitless alternative to the oppression of finality. These days in June gather together mathematicians, musicians, philosophers, and the author to formulate their own hypothesis in the shadow of their reading of the contemporary in the 21st century.

Yves André invited me as one of the mathematicians, and because of my deep respect for André’s writings about mathematics — and of course for his mathematical work — I was pleased to accept the invitation.

Badiou’s three-volume system is heavily based on set theory and much of the third volume is devoted to the theory of large cardinals, with chapters on ultrafilters, theorems of Scott, Jensen, and Kunen, 0#, and much more.  I have no idea what the upcoming Columbia graduate workshop will make of all this.  My own presentation had nothing to do with set theory; my aim was to explain why Badiou was wrong to hint in his book, in passing, that the mathematics of Andrew Wiles belonged with the “waste,” or at best the “archives.”  You can watch my talk or you can read it (preceded by a couple of pages explaining my misgivings about the theme of the conference).

I have to confess a less highbrow motivation, though.  Here is an excerpt from a review by Stanley Chang of Mathematics without Apologies that appeared in Society, dated June 25, 2018.

Other reviewers, both academics and nonacademics, have quite forcefully deprecated his use of ideas without context, the irrelevancy of various sections, an unreadably poor organization, and a purposely opaque stream-of-consciousness that prohibits understand [sic] rather than encourages it. One of my own friends, an anthropologist in academia, laughingly said that his treatment of Badiou is something that you would expect from a bad first-year philosophy essay from a bad student at a bad university.

Although Chang gave excellent reasons for his evident dislike of the book, he went out of his way to give it a fair reading, and I have no problem with his review.  But why did he make up this part about Badiou?  MWA contains no “treatment of Badiou.”  According to the index, Badiou’s name appears three times, and only in endnotes.  Two of the references are direct quotations, without anything that can be construed as a “treatment,” and the third quotes Juliet Flower MacCannell’s comments on a quotation by Badiou regarding Lacan’s theory of love, along with Vladimir Tasić’s gloss on the quotation and the comments.

In the Q&A following my talk in Paris I got a laugh from Badiou by suggesting that the mere mention of his name would provoke the laughter of many American philosophers, not to mention anthropologists.  But I don’t think that explains Chang’s sentence.  Maybe he was confusing Badiou with Bourdieu?  Or maybe the treatment in question was on this blog, for example here?

I would fault the editors of Society for allowing the publication of that last sentence, or any sentence, on any subject whatsoever, that quotes an anonymous anthropologist — laughing no less — for the sole purpose of taking a cheap shot.  But in fact I have no idea what the sentence is about.

Short proofs

August 2018 was this blog’s busiest month in two years.  Practically all the visits came in the first two weeks, with much of the traffic arriving from Germany (1788 of 5574 views).  The explanation, apparently, is that Peter Scholze’s Fields Medal was announced the first day of the month, and the Hausdorff Institute of Mathematics in Bonn chose my blog post  as one of three “interesting and popular articles” on his work, along with the article Erica Klarreich published in Quanta two years ago, and my chapter in the book What is a Mathematical Concept? edited by de Freitas, Sinclair, and Coles.  Quanta‘s articles on mathematics are notoriously interesting and popular; my chapter on the “perfectoid concept” may or may not be interesting, but I can’t imagine why anyone would consider it “popular”; and the blog post — which, as you may remember, is a text that did not qualify for publication in The New Scientist, is somewhere in between.

Anyway, my WordPress dashboard informs me that the Hausdorff Institute’s recommendations were picked up by (Frankfurter Allgemeine Zeitung) as well as  These two sites, together with the Hausdorff Institute, my indefatigable colleague Peter Woit’s blog, and the inevitable Google and Facebook, accounted for most of August’s referrals.

This year’s Fields Medals were widely covered by the international press, with Scholze’s story featured most consistently, along with the unexpected drama of the theft of Birkar’s medal.  Apart from Ulf von Rauchhaupt’s rather insightful article (visibly influenced by my blog post, not always with full attribution), coverage was mainly as approximate as one might expect, and was more informative about the current state of science reporting than about the priorities of contemporary mathematics.  Most entertaining for me was the article on the French website, which included this surprising bit of news:

Scholze a donc incontestablement la bosse des maths, mais il ne s’agit pas de son seul talent. En effet, il faisait partie d’un groupe de rock à 17 ans, puis a été professeur d’histoire allemande à 24 ans.

Rough translation:  “Scholze unquestionably has the math bump [a French expression that derives from phrenological notions popular in the 19th century — apparently there really is such a cranial bump, though its connection to mathematics is dubious] but it’s not his only talent: he played in a rock band at age 17, then at age 24 became professor of German history [sic!]”  Instead of a byline the article refers to three sources:  DW, El País, and Quanta.  I strongly suspect the sources were consulted and consolidated by a robot reporter which offered its own intrinsically logical interpretation of the sentence that opens the El Pais article:

Con 17 años tocaba el bajo en un grupo de rock, con 24 se convirtió en el catedrático más joven de la historia de Alemania.

The news coverage also revealed something of the network of journalists’ local contacts.  Thus the New York Times consulted Jordan Ellenberg, while El País quoted José Ignacio Burgos; Le Monde went to the trouble of finding four different mathematicians to contribute sentences about each of the four medalists:  Laurent Fargues (for Scholze), Philippe Michel (for Venkatesh), Jean-Pierre Démailly (for Birkar), and, inevitably, Cédric Villani (for Figalli).

Practically every article alluded to Scholze’s refusal of the New Horizons Prize, already discussed on this blog in 2015.   This came as no surprise to me; in fact, I had already anticipated the hypothetical reader’s fascination with this telling detail in the article I had prepared for The New Scientist, with the following sentence about his motivations:

My guess — but it’s no better than anyone else’s — is that he decided that the priorities of Silicon Valley are just not compatible with those of the mathematical community, as he sees it.

This means something very specific to me, and it may mean something to mathematicians reading this post, but to the hypothetical New Scientist reader it means exactly that Scholze refused the prize because he refused the prize, a vacuous observation embellished with the enigmatic expressions “mathematical community” and priorities.”  As we already know, this sentence never made it into the pages of The New Scientist; but, much to my surprise, it was translated into Spanish, at least twice, and at least once into German.  In each case my sentence was promoted to the status of a “speculation,” although the journalists had absolutely no reason to treat me as an authority on the matter, and besides which, as, I already explained, in the context of a newspaper article my sentence was totally devoid of content.  (Though one could always hope that a particularly attentive reader will find it surprising that not only is these such a thing as a “mathematical community” – though the word “community” disappeared from the German version — but that it even has “priorities”.   The reader may be sufficiently intrigued to wish to learn more about this, in which case:  good luck!)

Apparently Scholze’s refusal of the $100,000 prize cried out so desperately for explanation that the journalists grabbed at the only straw they found.  If they had been a little more patient, though they could have waited until August 6, when Scholze’s own answer to the question appeared in his interview with Helena Borges in O Globo:

O que posso dizer é que aquele era um prêmio e que este é outro. E é tudo que vou comentar sobre.

Rough translation, which curious readers are invited to ponder:  “What I can say is that that [the New Horizons Prize] was one prize, and that this [the Fields Medal] is a different one.  And that’s the only comment I’m going to make about that.”

The other item mentioned in practically all the press coverage recalled how Scholze distinguished himself already at age 22 when (quoting O Globo again) he “transformou uma teoria de 266 páginas em um texto sucinto de 37 folhas” — “transformed a 266-page theory into a succinct text of 37 sheets.”  Most of the other sources, starting with Erica Klarreich’s article in Quanta in 2016, identified the overstuffed “266-page theory” as none other than my book with Richard Taylor.  There is an interesting lesson hidden in that story about radical abbreviation, but that’s a silly (as well as misleading) way of putting it.  I was hoping to explain why that’s the case before I present an overview of the proof of the local Langlands conjecture to the graduate reading group that meets at Columbia tomorrow afternoon, but unfortunately I have run out of time, and I’ll have to return to the question later.

Time to move on

wainua               Figure 6.1 (Clairaut's diagram)

Snail image:  Creative Commons licence courtesy of Te Papa; Clairaut’s love formula from Chapter 6 of MWA

My tireless editor Vickie Kearn at Princeton University Press has brought me the welcome news that Mathematics without Apologies will be coming out in a paperback edition next spring.   I started this blog for two reasons, and one of them — to clarify my intentions in writing the book — will vanish when I add two or three pages to the preface of the new edition.   The new pages — I have already written them — will devote one paragraph or so to each of four topics, provisionally under the headings charismamemoirsutility, and ethics; each paragraph will address some of the points raised by comments on this blog as well as in some of the more negative reviews.

My other reason  for starting this blog was to find some outlet for the wealth of material that I was not able to incorporate in the book.  Most of this material has remained untapped while I composed comments on current events or new findings, and I was idly wondering when I would get around to sifting through the 7 GB  or so that is gathering nanodust on my computer’s hard drive.  My Eureka! moment came when I realized that I had already devoted a considerable amount of my free time to writing the book during the better part of three years.  Perhaps I didn’t really want to return to the old material?  With the new preface, I can finally declare the book finished and move on to something else.

Will it be another book, maybe one that will win me the mythical seven figure advance?  Or will there be another blog, or the same one under another name?   That’s for the future to decide.  Meanwhile, this one will remain visible, but with no new entries.

My thanks to the regular readers and occasional visitors who helped keep the blog from slipping into solipsism.  And my special thanks to authors of comments who, by disagreeing, often sharply, with opinions expressed here, demonstrated that the meaning of mathematics is still a matter of controversy.

This was supposed to be the last entry, but I’m now thinking I should include part of the new preface material — or all of it, if PUP allows it.  Meanwhile, in order not to let anything go to waste, here is the post on which I was working when I realized that this blog had reached the end of its natural life…

I Cunfirenti

This was originally going to be an appendix to the playlist near the end of Chapter 8:  an exploration of the attitude to mathematics in the genre of organized crime ballads.  The deeper meaning of Rick Ross’s 2009 single Mafia Music was exposed even before it was released,  but I was unable to find an interpretation of the unexpected appearance of mathematics in the middle of this rap à clef:

I thought about my future and the loops I could pin.
Walked out on a gig and I turned to da streets,
Kept my name low key, I ain’t heard from in weeks.
I came up with a strategy to come up mathematically,
I did it for da city but now everybody mad at me.

Apart from Rick Ross, Gödel is the only person Google finds who can “come up mathematically.”  My guess is that Ross’s strategy (unlike Gödel’s) involves money.  But Ross is not really a gangster, and Mafia Music is not really a mafia song at all; in fact, by naming names the song breaks what I’m told is the most fundamental of all the rules of the Italian Malavita, namely the rule of omertà, the iron law of silence.

Now it struck me when I saw this that the mathematical profession has its own version of omertà, probably not very different from other forms of academic rules of silence, having to do with forms of behavior that straddle the line that divides the unpleasant from the unethical.  The behavior protected by mathematical omertà differs from other varieties in that it tends to inspire less literary commentary.  Instead it consists in scandalous rumors whispered in corridors when they are not being shouted across barroom tables, but that must under no circumstances be mentioned in public.  (There was a scurrilous exception in a well known literary magazine a few years ago, but I will not dignify it with a link.)

I am particularly sensitive to this rule just now, because in the past few weeks I was shocked to learn of abuse of power by several colleagues I would not have believed capable of such behavior (and by a few others I can easily believe capable of anything).  Whether being the repository of such confidences is one of the perks of my charisma, or whether it’s the abusers who feel newly entitled as a result of their own charisma, the mildest punishment I could expect if I chose to betray the dark secrets of the mathematical profession is not to be privy to such secrets in the future.  Breach of Mafia omertà is treated more harshly than that.  Many of the songs on the delightful album La Musica della Mafia are devoted to the many kinds of punishment the gangster ethic  —

Laws that don’t forgive those/Who break their silence

reserves for traitors — cunfirenti, in Calabrian dialect.  For example, the song entitled I cunfirenti promises that they will find “their final resting place in concrete walls” (‘Mpastati ccu cimentu e poi murati).

The album’s title is imprecise; it’s not a collection of songs of the Sicilian mafia but rather the ballads of their Calabrian declension, the ‘Ndrangheta, who deserve to be better known, and not only for their songs:

Its success at drug smuggling catapulted the ‘Ndrangheta past its more storied Sicilian rival, the Cosa Nostra, in both wealth and power. Italian authorities now consider the ‘Ndrangheta to be Europe’s single biggest importer of cocaine.

What I find most charming about this collection is the contrast between the lively rhythms of many of the songs and the uniformly grim, often bloody, content of the lyrics.  For example:

Malavita, malavita
Appartegnu all’Onorata
Puru si c’impizzu a vita
Eu nun fazzu na sgarrata

Which means

Malavita, malavita!
I am one of the honorable society.
And even if it costs me my life,
I will never surrender.

If you’re looking for mathematical content you have to skip to the last verse:

Ed eo chi tingu sangu ´nta li vini
Su prontu d’affruntari mille infami
A chista genti ci rispunnimu
Pidi sunu pronti centu lami

Which means

And I who have blood flowing through my veins
Am ready to face 1000 traitors
As they know all too well
That 100 sharpened knives are ready for them.

Is it common knowledge that anyone is fit to be US President?


A few weeks ago, Terry Tao used Donald Trump’s perceived lack of qualification for the presidency to illustrate the difference between mutual knowledge and common knowledge, in a blog post with the normative title It ought to be common knowledge that Donald Trump is not fit for the presidency of the United States of America.  It’s common knowledge that Terry Tao, in addition to being one of the Mozarts of mathematics, is a very sensible person, and like every sensible person he is appalled by the prospect of Trump’s election as president.  As an attempt to account for this unwelcome prospect, Tao suggested that the correctness of Proposition 1 above is a matter of mutual knowledge  —

information that everyone (or almost everyone) knows

but not (or not yet) common knowledge

something that (almost) everyone knows that everyone else knows (and that everyone knows that everyone else knows that everyone else knows, and so forth).

It seems to me, though, that Tao’s formulation of the question — whether Trump is “fit for the presidency” or, in the words of Proposition 1, is “even remotely qualified” — is ambiguous.  The only axiomatic answer is the one provided by Article II, Section 1 of the U.S. Constitution, which implies unequivocally that Trump, like me but (unfortunately) unlike Tao, is indeed “eligible to the office of President” — though I admit I haven’t seen his birth certificate — and eligible is here the only word that is unambiguous and legally binding.

Now I realize that, even if you are a mathematician and therefore legally or at least professionally bound to respect the axiomatic method, you will object (at least I hope you will) that Tao did not mean to suggest that Trump’s bare eligibility was in question, but rather that Trump did not meet the more stringent criteria of fitness or even remote qualification.  By analogy, no one would deny that  ø (the empty set) is eligible to be a set, according to the usual axioms of set theory, but rather that

  1. ø is hardly anyone’s favorite set;
  2. ø is in no sense a paradigmatic set; and
  3. ø is not the kind of set for which set theory was designed.

Thus, even if it were mutual or even common knowledge that Trump is, so to speak, the empty set of American politics, that would hardly count as a consensus on his fitness or even remote qualification.  I’m naturally sympathetic to this kind of argument, but Tao made it clear that only comments that

directly address the validity or epistemological status of Proposition 1

were eligible for consideration on his blog.  While I’m hardly a strict constructionist, I don’t see how to avoid interpreting the word epistemological in terms of the maximal epistemological framework I share with Tao, which in this case can only be Article II, Section 1 (together with the Zermelo-Fraenkel axioms, but I doubt they are of much help here).

I was already leaning to a different explanation of the Trump phenomenon before offered this helpful but depressing roster of the worst (and best) presidents in the history of the United States, according to (unspecified) “scholars.”  Running down the list, one sees that, although Barack Obama is undoubtedly one of the most fit of all the presidents, intellectually as well as academically speaking, he only shows up near the middle of the ranking.  Presumably this is because he has been less effective as a politician than the presidents at the top of the list.  Judging by his words, I would like to say that Obama is one of the most morally fit of the presidents on the list; judging by his deeds, on the other hand — these, for example, or these — the record is much less appealing.  Jimmy Carter has proved to be both intellectually and morally admirable since leaving the presidency, but he made two of the biggest foreign policy blunders in recent history while in office (he ranks quite poorly on the list, probably for different reasons).

It is clearly mutual knowledge that the notion of fitness to lead a modern democracy, in particular fitness for the presidency of the USA ,correlates strongly with a shocking disdain for the notion that elections are designed to reflect the popular will.   My sense is that Trump’s supporters, and their counterparts across Europe, would like this to be common knowledge.  Fortunately, they are not the only ones.

This will be the next-to-last post for the summer; the next post will explain why it may be time to put this blog to rest permanently.



Alexander-Jazz-of copy

Nearly three months have passed since I had the privilege of sharing the stage with Stephon Alexander at Book Culture, near Columbia.  MWA had been out for over a year, but I had put off reporting on the (very moderately attended!) event until Alexander’s book was available.  Alexander is both an accomplished theoretical physicist (“specializing,” as the event blurb indicates, “in the interface between cosmology, particle physics and quantum gravity”) and a respected jazz saxophonist.  “Respected” meaning:  when he walks into a downtown jazz club, the owner comes out to greet him.  

The Jazz of Physics is a fascinating read, as I’ll let you discover for yourselves.  Or perhaps you have already discovered the book; as of this writing , it is listed on as #1 best-seller in quantum physics AND #2 best-seller in jazz, which must be a first.  Of course Alexander had to overcome the first obstacle that faces the author of any popular science book, namely:  when communicating ideas that only a few specialists really understand (and even then imperfectly and provisionally), how to draw the line between making them accessible and making them trivial?   Alexander uses jazz, and music more generally, as the basis for a series of increasingly complex and precise analogies with physics, especially his own work on the quantum mechanics of the early universe.  It works — readers and reviewers seem to be happy with the results — but I want to suggest that jazz is not merely used as a metaphor in this book.  If I understand the conclusion correctly, by the end Alexander is suggesting, plausibly, that the structure of the universe is itself improvisational, so that jazz turns out to be a surprisingly effective (even “unreasonably effective”) route to understanding cosmology.

I’ll leave the speculation at that.  When I was putting together material on the attitudes of musicians to mathematics, I did not search systematically but rather collected enough examples to establish what seemed to me general patterns, to wit:  classical musicians and rockers for the most part refused to acknowledge an affinity with mathematics, but African-American popular musicians — especially in rap and techno — seemed to hold mathematics in high regard.  (I met Alexander when I was putting this together and he gave me a few precious tips.)  I was frustrated to have found no meaningful material on the relations of jazz musicians to mathematics, but not frustrated enough to explore the question in a scholarly manner.

Alexander’s book doesn’t settle the question, but he does establish that some of the biggest names in jazz were seriously interested in physics.  He mentions Ornette Coleman, John Coltrane, and Yusef Lateef:

About a decade ago, I sat alone in a dim café on the main drag of Amherst, Massachusetts, preparing for a physics faculty job presentation when an urge hit me. I found a pay phone with a local phone book and mustered up the courage to call Yusef Lateef, a legendary jazz musician, who had recently retired from the music department of the University of Massachusetts, Amherst. I had something I had to tell him.…

“Hello?” a male voice finally answered.
“Hi, is Professor Lateef available?” I asked.
“Professor Lateef is not here,” said the voice, flatly.
“Could I leave him a message about the diagram that John Coltrane gave him as a birthday gift in ’67? I think I figured out what it means.”

There was a long pause. “Professor Lateef is here.”

The diagram is pictured in the Introduction to The Jazz of Physics, with the helpful caption “any other reproduction is prohibited.”  So you will have to read the book if you want to see what Alexander and Lateef had to say to each other.

The theologico-teleological apology


Comments on David Roberts’s Google+ page, May 30, 2016

David Roberts’s announcement a few months ago of his then-forthcoming review in the Gazette of the Australian Mathematical Society sounded like a warning shot, especially since I occasionally had the impression that he was trying to bait me on this blog.   The review is now out, and as far as I’m concerned it’s perfectly fair; the reviewer was even thoughtful enough to include what trade jargon calls a pull quote in the last paragraph, and you can expect to see it soon enough on the reviews page.

The review also provides (yet another!) opportunity to clear up some misconceptions, notably about charisma, as used in chapter 2.  I chose the word deliberately as a provocation, but it provokes different readers in different directions, and that’s beyond the author’s control.  The ambiguity of the word is already in Weber, it seems to me:  the charismatic leader is separated from the masses by an aura, while those possessed of routinized charisma are part of the mass of functionaries that make the community… function.  I tried to make it clear that chapter 2 was the (fictionalized) story of my acquisition of routinized charisma, in other words, of being accepted as a legitimate functioning member of the community.  So when Roberts writes

The ‘relaxed field’ that Harris discusses … is perhaps not the same for us as for those with charisma.

he is making a distinction that is quite alien to the spirit of the book; indeed, Roberts is displaying a paradigmatic form of charisma by publishing a book review in the Gazette of his learned society, and more consistently in his contributions to MathOverflow and other social media.

By the way, saying that chapter 2 was fictionalized is not the same as saying that it was made up; what I meant was, first, that it was written in acknowledgment of the narrative conventions of (a certain kind of) fiction; and that it didn’t matter for my purposes whether or not the events recounted were strictly true, as long as they were ideal-typical.

Roberts reads MWA as calling charisma a form of prestige whose acquisition is one of the motivations for doing mathematics, but this was not my intention.  No doubt mathematicians find it gratifying when our work is recognized, and much of the mass of chapter 2 is devoted to prizes and other forms of recognition, large and small, institutionalized or informal; but only André Weil is represented as actually craving prestige, and the context makes him recognizably an outlier.  An obsession with ordered lists and rosters of Giants and Supergiants is attributed to the community, rather than to individual mathematicians who hunger for recognition.  This obsession is such a visible feature of contemporary mathematics that it deserves explanation, and chapter 2 suggests an explanation that is so counter-intuitive that it seems not to have been noticed by anyone (on pp. 18-19):

The bearer of mathematical charisma… contributes to producing the objectification—the reality—of the discipline, in the process producing or imposing the objectification of his or her own position within the discipline.…The symbolic infrastructure of mathematical charisma is… the “objectification” of mathematics:  the common object to which researchers refer… In other words, it’s not just a theory’s contents that are defined by a social understanding:  so are the value judgments that organize these contents.

This brings me to Urs Schreiber’s instructive misreading of MWA‘s intentions, quoted above.  Most likely it’s a misreading based on no reading at all of MWA, because he seems not to be aware that the words “meaning” and “reality” that he cites as the aims of a self-aware mathematician are examined repeatedly in MWA, especially in chapters 2, 3, and 7.

Chapter 3 refers to three main forms of “apologies” for mathematics, labelled in keeping with the western philosophical tradition as “good, true, and beautiful.”  The word “tradition” is fundamental.  The one thing I find unforgivable when mathematicians make general comments about the values and aims of mathematics is the suggestion that they are saying something original.  Talk of values and aims is necessarily embedded in a philosophical and literary and social tradition; a failure to acknowledge this is merely a sign of ignorance, not of intellectual independence.  THAT is why MWA has nearly 70 pages of endnotes and more than 20 pages of references:  in order to record the author’s efforts to purge himself of the notion that his ideas are his own — and, no doubt, to encourage others to take the same path.

MWA cites those three main forms of “apologies” because they are the ones actually on offer; writing about them is my way of grappling with “reality.”  I attended the meetings described in chapter 10 not out of masochism (the champagne receptions were not bad at all) but because they were really happening, they were organized and attended by real decision-makers (“Powerful Beings”) whose decisions have real consequences for the future of the discipline; and the representations of mathematics (and of scientific research more generally) presented at those meetings were the real attempt of the community to procure the external goods necessary for its survival in its present form.  (I procured no pleasure, not even Schadenfreude, when I read the documents listed in the bibliography under “European commission”; but they are terribly important for anyone who is concerned about the future of mathematics.)

Anyway, Schreiber’s speculations cited above are irrelevant to MWA, but they are instructive nevertheless, because they exemplify what might be considered a fourth kind of apology that might be called Theologico-teleological.  One doesn’t need to believe in a supreme being to be a seeker of “answers to deep questions” or “meaning” or “reality,” but one has to believe in something.  I don’t know how to attach consistent meanings to the terms in quotation marks in the last sentence, and I don’t think Schreiber does either.  But I do know one name that has been given to the process by which meanings accumulate around terms like that:  tradition-based practice, specifically in the writings of Alasdair MacIntyre.  Two separate texts, both cited in the bibliography, led me to MacIntyre:  David Corfield’s article Narrative and the Rationality of Mathematics Practice and Robert Bellah’s book Religion in Human Evolution, which I read at the suggestion of Yang Xiao.  Both texts propose ethical readings of important human social phenomena, and this is important to me, because I have found that most arguments about the nature of mathematics, including Schreiber’s comments, turn out to be ethical arguments in disguise.

(Like “beauty,” the “answers to deep questions” or “meaning” or “reality” that Schreiber appears to be seeking can also be interpreted as euphemisms for “pleasure,” but I will leave this for another occasion.)

The seven figure advance

It’s not a myth.  Two people I know reported this spring that they were offered, and accepted, advances for forthcoming books in excess of $1,000,000.  The authors are serious and knowledgeable people and their books will be informative and will probably sell pretty well.  After their agents take their cuts, they will be able to live comfortably in New York City for several years while planning their next projects.

But will the publishers recover their investment?  [The contributor of this comment will want to skip the rest of this paragraph.]  They will undoubtedly try.  The authors both warned me that accepting a sizable advance entails surrendering control to the publisher of the final product, as well as much of one’s free time.  There will be unwelcome editorial changes as well as a grueling schedule of book tours, often with wine and cheese.   But a quick calculation (not taking into account eventual sales of merchandise, video games, TV contracts, ringtones, and secret revenue streams that the profession has yet to reveal to me) suggests that the publisher will have to count on six figure sales to recover a seven figure advance.  How realistic is that?

Not very, according to Lynn Neary, reporting last September on Weekend Edition:

So what is a good sales figure for any book?

“A sensational sale would be about 25,000 copies,” says literary agent Jane Dystel. “Even 15,000 would be a strong enough sale to get the publisher’s attention for the author for a second book.”

But if that second book doesn’t sell, says Dystel, odds are you won’t get another chance.

By this measure, Eugenia Cheng’s How to Bake π: An Edible Exploration of the Mathematics of Mathematics has been a sensational success, according to a richly illustrated feature article that appeared in the New York Times two weeks ago.   The Times reports that Cheng’s book has sold just about 25000 copies in the US alone, not counting translations.   As for other aspiring writers, Neary’s news is not good.

Just over 1,400 full- and part-time writers took part in the [2015 Authors Guild survey], the Guild’s first since 2009. There has been a 30 percent decline in author income since then and more than half of the respondents earned less than $11,670 (the 2014 federal poverty level) from their writing related income.

“No one likes to see the word ‘poverty level’ on a survey that has anything to do with people you know,” says Roxana Robinson, president of the Authors Guild. “You used to be able to make an absolutely living wage as a writer. You wrote essays and you published them in journals. You wrote magazine pieces and you got paid very well for those. And you wrote books and you got good advances. So being a writer, it didn’t usually mean you would be rich, but it had meant in the past that you could support yourself.”

What happened?

The Authors Guild blames the decline in writers’ income on a combination of factors: online piracy of digital material, consolidation within the publishing industry which has led to more focus on the bottom line, the dominance of Amazon and the rise of self-publishing which has cut into the market for traditional publishers.

The Times portrait of Cheng was charming but mathematically slight.  Steve Strogatz had a cameo, which is not so surprising, since he’s well-known to Times readers for his Joy of X columns, and maybe also because he has managed the exceedingly rare feat of writing successful popular books about mathematics with real content.  More unexpected is a quote from John Baez that gives the reader only the slightest hint of his legendary exuberance:

“Eugenia has gone all the way in,” he said. “She’s trying to explain math to everybody, with or without pre-existing expertise, and I think she’s doing wonderfully.”

The Times author, it’s safe to say, did not go “all the way in.”  There is Cheng’s helpful illustration of associativity with a custard recipe.

You must first combine the sugar and egg yolks and whisk them into a froth before you pour in the cream.

Blend the ingredients in a different order, [Cheng] said, “and you end up with a runny mess.”

To illustrate mathematics, on the other hand, the Times author chose a problem from elementary algebra; hardly the Baez-Dolan Cobordism Hypothesis.

Now for the question on all your lips:  how is MWA doing, on literary agent Jane Dystel’s scale?  Well, it has a long way to go before anyone will call its sales “sensational,” and it may never get there.  But the book is in its second printing, Princeton University Press has more than recovered its (modest!) advance, and discussions of motion picture rights — as it says in my contract

(b) For the licensing of dramatization, public reading, radio, video, sound recording, and motion picture rights, you will receive 75% of the net amounts received by the Press. —

have yet to begin.