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Titans of Mathematics Clash Over Epic Proof of ABC Conjecture (quantamagazine.org)

Two mathematicians have found what they say is a hole at the heart of a proof that has convulsed the mathematics community for nearly six years. Quanta Magazine: In a report [PDF] posted online Thursday, Peter Scholze of the University of Bonn and Jakob Stix of Goethe University Frankfurt describe what Stix calls a "serious, unfixable gap" within a mammoth series of papers by Shinichi Mochizuki, a mathematician at Kyoto University who is renowned for his brilliance. Posted online in 2012, Mochizuki's papers supposedly prove the abc conjecture, one of the most far-reaching problems in number theory. Despite multiple conferences dedicated to explicating Mochizuki's proof, number theorists have struggled to come to grips with its underlying ideas. His series of papers, which total more than 500 pages, are written in an impenetrable style, and refer back to a further 500 pages or so of previous work by Mochizuki, creating what one mathematician, Brian Conrad of Stanford University, has called "a sense of infinite regress."

Between 12 and 18 mathematicians who have studied the proof in depth believe it is correct, wrote Ivan Fesenko of the University of Nottingham in an email. But only mathematicians in "Mochizuki's orbit" have vouched for the proof's correctness, Conrad commented in a blog discussion last December. "There is nobody else out there who has been willing to say even off the record that they are confident the proof is complete." Nevertheless, wrote Frank Calegari of the University of Chicago in a December blog post, "mathematicians are very loath to claim that there is a problem with Mochizuki's argument because they can't point to any definitive error." That has now changed. In their report, Scholze and Stix argue that a line of reasoning near the end of the proof of "Corollary 3.12" in Mochizuki's third of four papers is fundamentally flawed. The corollary is central to Mochizuki's proposed abc proof. "I think the abc conjecture is still open," Scholze said. "Anybody has a chance of proving it."

60 of 105 comments (clear)

  1. In poor jest by Anonymous Coward · · Score: 3, Funny

    I guess it isn't as easy as 1,2,3...

    1. Re:In poor jest by sconeu · · Score: 3, Funny

      What about Do-re-mi? Or you and me?

      --
      General Relativity: Space-time tells matter where to go; Matter tells space-time what shape to be.
    2. Re:In poor jest by lgw · · Score: 5, Informative

      The ABC theorum is a bit hard to explain. The best I can do is taken from Wikipedia: If:
      * A, B, and C are co-prime
      * A + B = C
      * D = the product of the unique prime factors of A, B, and C
      Then D is usually not much smaller than C.

      Or, put a different way, if A and B are high powers of primes, C probably isn't. For example:
      * A = 64 = 2^6
      * B = 81 = 3^4
      * C = 145 = 5*29
      * D = 870 = 2 * 3 * 5 * 29

      In that example, the prime factors of C were to the first power, so D was a multiple of C. That's pretty normal.

      This apparently has much broader consequences when generalized broadly to number fields, but I've never gotten my head around "primes" in fields other than integers.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    3. Re:In poor jest by Anonymous Coward · · Score: 1

      My roommate at Caltech showed how you can "almost" prove Fermat's last theorem (only finitely large number of solutions possible for A and B being co-prime) using this conjecture and that is the time I learned the power of this conjecture. I am not a mathematician but still it felt very interesting.

    4. Re:In poor jest by TeknoHog · · Score: 1

      The ABC theorum is a bit hard to explain.

      Not as hard as it is to spell "theorem". *rimshot*

      --
      Escher was the first MC and Giger invented the HR department.
    5. Re:In poor jest by rtb61 · · Score: 1

      To put in another way maths geeks often get lost in the unreality of numbers. Maths might seem all hard and real like physics, but really it is not and for the most obvious reason. It is the number of 'somethings' that make math real, where there is no something, than maths becomes purely relative, an empty dance of numbers. It is the something that makes math real, applying the math to the actual real world, theoretical math, tends to drift off into a world of patterns. When you go there, as deep as you can go and you can end up with reality being 'patterns regimented by choice' and fractional infinity.

      Without something to tie the math to, the math theory becomes pretty fluid. The most interesting thing about math now, simulations, never ending calculations.

      --
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    6. Re:In poor jest by Anonymous Coward · · Score: 1

      Math is a priori, pure reason. It has no and needs no connection to the evidence which makes up reality.

      Math is not the language of the universe. Math is one language to describe the universe.

    7. Re: In poor jest by datavirtue · · Score: 1

      If my ten year old can't understand it it is wrong. Back to the drawing board dumbass.

      --
      I object to power without constructive purpose. --Spock
    8. Re:In poor jest by gringer · · Score: 1

      I've never gotten my head around "primes" in fields other than integers

      That might be because the integers aren't a field.

      --
      Ask me about repetitive DNA
    9. Re:In poor jest by lgw · · Score: 1

      Thank you captain pedantic. Does "primes other than integers" make you feel better?

      --
      Socialism: a lie told by totalitarians and believed by fools.
    10. Re:In poor jest by acvh · · Score: 1

      I'm sure your explanation works for some; but the linked article in the summary actually has a great layman's explanation that is extremely clear.

    11. Re:In poor jest by Hognoxious · · Score: 1

      They wear a funny hat, keep one hand down their pants and like to conquer most of Europe?

      --
      Confucius say, "Find worm in apple - bad. Find half a worm - worse."
    12. Re:In poor jest by lgw · · Score: 1

      My virtual funny mod to you this day.

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      Socialism: a lie told by totalitarians and believed by fools.
  2. Isn't this one of AI's applications? by mykepredko · · Score: 1

    I thought theorem checking was one of the applications that AI was being touted for. Just doing a quick check, there seems to be a large number of articles (like this one, which goes back a bit: http://www.dtic.mil/dtic/tr/fu...) written about this very topic.

    Rather that rely on a limited number of mathematicians, all of whom seem to know Professor Mochizuki, how about running his proof through these AI tools to see if they can validate the proof?

    1. Re:Isn't this one of AI's applications? by Pinky's+Brain · · Score: 2

      Considering how obtuse mathematician's found the proof, rewriting it into something a proof assistant could parse was almost certainly a mammoth task. Trying to nitpick errors in the proof was almost certainly a better use of time.

    2. Re:Isn't this one of AI's applications? by Anonymous Coward · · Score: 5, Funny

      I thought theorem checking was one of the applications that AI was being touted for. Just doing a quick check, there seems to be a large number of articles (like this one, which goes back a bit: http://www.dtic.mil/dtic/tr/fu...) written about this very topic.

      Rather that rely on a limited number of mathematicians, all of whom seem to know Professor Mochizuki, how about running his proof through these AI tools to see if they can validate the proof?

      Hi, My name is Euclid Pascal-Poincaré, Professer of Mathematics at the Nigerian Institute of the 409 Theorems. Nobody has ever had a thought as brilliant as yours my friend. And I should know, since I have received the fields medal three times, as the youngest (age 7), most successful (age 22) and oldest (age 57) awardee. The idea of applying an AI proof machine which could obviously solve the problem to a proof that is obviously too easy for it would be something that our institute would pay dearly for. Your place is guaranteed.

      I have a research lab and $1,500,000 (One billion and ifty million dollars) and twelve beautiful virgin assistants waiting for you in Nigeria. All you have to do to claim your position is to wire $432 + $71422 (four hundred thousand and twenty two pounds to) to UK Bank: Nat West, Sort code: 60-16-03 Account number: 73754900.

      I am looking forward to greet you at our newly built facility with it's four hundred swimming pools and banks of tens of mechanical calculating machines.

    3. Re:Isn't this one of AI's applications? by 110010001000 · · Score: 1, Troll

      You do know that AI isn't real, right? What they call "AI" is just "neural" networks which have been around for decades.

    4. Re:Isn't this one of AI's applications? by Anonymous Coward · · Score: 1

      Seems like rewriting it to something that could be followed is exactly what is needed.

    5. Re:Isn't this one of AI's applications? by lgw · · Score: 4, Funny

      Neural networks are "really AI" in the same sense that chickens are really dinosaurs: the experts in the field get to define the terms. Except for Pluto, which remains a planet regardless.

      --
      Socialism: a lie told by totalitarians and believed by fools.
    6. Re:Isn't this one of AI's applications? by gweihir · · Score: 1

      Only works for fully formalized proofs and a human has to explain the proof to the system in detail. That means it takes a lot of time to do and needs a human that fully understands the proof.

      Also, this is not actually AI in any meaningful sense, it only gets in there because of the AI hype.

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    7. Re:Isn't this one of AI's applications? by gweihir · · Score: 1

      In addition, interactive proof assist systems do not even use neural networks.

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    8. Re:Isn't this one of AI's applications? by pjt33 · · Score: 1

      As with much of AI, there has been progress but there is still a way to go. In particular, the input format for theorem checkers is not yet the mathematical paper. I'm not aware that anyone apart from Mohan Ganesalingam and his collaborator Thomas Barnet-Lamb have worked on parsing mathematical papers into something which could be supplied to a theorem checker; Ganesalingam's 2013 book The Language of Mathematics: A Linguistic and Philosophical Investigation gives an idea of the challenges and limitations of such an approach.

  3. Proofs are established subjectively by iMadeGhostzilla · · Score: 1

    That's true even for simple things: you look at the Pythagorean theorem and at some point the proof of the theory "clicks" somewhere inside you and you say yes this is true. A genius friend at the university argued with his mathematics professor on some advanced course as he didn't give my friend the full credit on some very complicated proof, and he said "see here, colleague" (they call all students "colleague"), "the mistake is you wrote this orientation here is clockwise but it's counter-clockwise". The student said "no it is clockwise." The professor looked back at the paper and asked (aware of the student's genius and reputation) "why is it clockwise?" And the friend said "But it must be!" And the professor looked again and said "yeah, you're right, it is."

    1. Re:Proofs are established subjectively by Krishnoid · · Score: 1

      "Now for extra credit: explain this to someone a couple levels dumber than either of the two of us."
      "Clockwise vs counter-clockwise, I can handle. But that? Now you're just being screwy."

    2. Re:Proofs are established subjectively by cb88 · · Score: 1

      Sometimes you establish a convention to do a calculation or proof, and that apparently was not well defined in that case but apparently it was used consistently otherwise the professor would not have conseded.

      And example is the right hand rule (a convention), and the + or - nature of electrons (we actually got it backwards from reality but since it's just a convention it doesn't matter in practice we just had to choose a polarity and go with it consitently).

    3. Re:Proofs are established subjectively by mlyle · · Score: 1

      Plenty of proofs have a very strong objective basis. E.g. all of the mathematics that has been proven (and verified) within systems of simple symbolic manipulation like Whitehead established in the Principia Mathematica.

    4. Re:Proofs are established subjectively by pjt33 · · Score: 1

      I think that GPPs point can perhaps be reworded as "We write proofs to convince other humans, not to convince theorem provers". There are some theorems whose proofs have been verified automatically, and others which only have computer-assisted proofs (e.g. the four colour theorem, or the theorem formerly known as the Kepler conjecture), but from a philosophical point of view a proof is considered a proof if it convinces the experts in the field.

  4. Humbling by ebonum · · Score: 2

    Understanding what the abc conjecture states takes effort. Proving it...
    A reminder of just how different a real mathematician's mind is from the rest of us.

    1. Re:Humbling by sycodon · · Score: 1

      Is this problem an academic one or are there real world implications for this turn of events?

      --
      When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
    2. Re:Humbling by neoRUR · · Score: 1

      Yes, even Geniuses don't always know how to get the answer, sometimes they just know the answer.
      Watch this movie, it's a good movie about a good Genius who's mind was faster then his though process.
      https://en.wikipedia.org/wiki/...

      Its a movie about Ramanujan.

    3. Re:Humbling by Anonymous Coward · · Score: 1

      Until sometime down the line, someone comes up with a use for it.

      Like taking prime number theory and making public private key encryption, that lets you safely conduct business online

  5. Re:The people wrong must be banned from Math by bobbied · · Score: 4, Insightful

    Let's start defining some stakes.

    If you come up with a proof and it's wrong, you're banned from Math.

    If you say a proof is wrong and it turns out you are wrong, you're banned from Math.

    Solving challenging problems can earn you "Unbanned from Math" cards, but they must be incredibly challenging.

    So... Einstein would have been banned from theoretical physics using your rules. His original theory of Special Relativity was wrong in some cases, so we got "general" relativity as a correction... With your rules we would have banned him.

    I wouldn't be too quick to "ban" anybody, unless they *should* have known better or they obviously violated the rules of math with their work and tried to hide it. You punish willful deception (those who are lying and know it), but mistakes and oversights are part of the human experience and why we have peer reviews. If you get found to have made mistakes or overlooked something, your reputation will suffer but you should be allowed to correct and proceed.

    --
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  6. Re:Socialism by AutodidactLabrat · · Score: 1

    Famous Russian Troll error, unable to incorporate THE and A into the language.

  7. Re:Socialism by fattmatt · · Score: 1

    I think technically they are FCC 1984 phones (Reagan phones) but who cares, those who keep beating that drum are already dead for the most part.

  8. How is any of this relevant by halfdan+the+black · · Score: 1

    Seriously, how is this relevant to anyone on the planet besides the author himself, and the 10 other people who've read his work.

    1. Re:How is any of this relevant by Kaenneth · · Score: 1

      Possibly to generating large prime numbers for cryptography?

      Or has everyone moved on to elliptic curves anyway?

    2. Re:How is any of this relevant by novakyu · · Score: 1

      10? Which optimism training school did you go to?

    3. Re:How is any of this relevant by gweihir · · Score: 3, Insightful

      You know what most of modern CS is based on? Mathematics, sometimes done thousands of years ago. This is relevant and that is why we keep these people around.

      --
      Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
    4. Re:How is any of this relevant by 101percent · · Score: 1

      The whole thing that makes a mathematicianâ(TM)s life worthwhile is that he gets the grudging admiration of three or four colleagues. -knuth

  9. Numberfile explains the ABC conjecture by swm · · Score: 3, Informative
    Numberfile gives a good intro to the ABC conjecture

    https://www.youtube.com/watch?...

  10. Re:The people wrong must be banned from Math by cowpie · · Score: 2

    Why is this voted up!?!?

    General Relativity was not a correction to Special Relativity. They're about completely different things! Special Relativity is about the speed of light being a constant in all reference frames and the implications of that. General Relativity is about how mass distorts spacetime giving rise to gravity.

    I agree with your point that bans are bad, but stop trying to sound smart using Einstein as an example until you learn more about him, OK?

  11. Re:The people wrong must be banned from Math by Pseudonym · · Score: 1

    Special Relativity is about the speed of light being a constant in all reference frames and the implications of that.

    If you actually read Einstein's original paper on special relativity, you'll find that it's about electrodynamics.

    --
    sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
  12. actually by thePsychologist · · Score: 4, Interesting

    I think the title here is misleading. Outside of Mochizuki's friends (and perhaps even including them), every mathematician involved has had serious doubts about this purported proof since the beginning. That's simply because the papers are written very different than the usual math paper ---- that is to say, leaving very many things not explained or explained poorly.

    --
    "What lies behind us, and what lies before us are tiny matters compared to what lies within us." Ralph Waldo Emerson
    1. Re:actually by the+phantom · · Score: 1

      This is not at all true. First off, mathematics itself has many different highly specialized sub-fields, many of which don't communicate effectively between each other. An complex analyst and a homotopy theorist speak very different mathematical languages, and may have difficulty communicating their ideas to each other. It is reasonable to suggest that this represents a different "cultural" background (as per Tylor's definition, these differences are differences in knowledge and belief, as well as differences in language).

      Additionally, mathematicians from different parts of the world conduct mathematics differently. The internet and the wide-spread adoption of English as the de facto language of discourse has ameliorated this problem some in recent history, but there are still very significant cultural differences between American, European, Russian, and Japanese mathematics (for example). The approach that one takes in tackling a mathematical problem does depend quite a bit on where one learns it. As a historic example, Ramanujan was interesting to Hardy not just because he was producing interesting results, but because he was producing these results in an idiosyncratic way which differed immensely from the British approach.

      Hence the original question

      is it obtuse because he's trying to pull a fast one, or does it appear obtuse because he's form a different cultural background than?

      is entirely reasonable.

    2. Re:actually by the+phantom · · Score: 1

      Shinichi Mochizuki has a solid history of producing good mathematics. While it is possible that he is trying to pull a fast one, that seems quite unlikely, given his reputation. The most charitable explanation is that he has invented a new branch of mathematics (the "inter-universal Teichmüller theory") in order to resolve the ABC Conjecture, and that the "newness" of this approach is causing difficulty for outsiders.

  13. Re:The people wrong must be banned from Math by thePsychologist · · Score: 1

    If you come up with a proof and it's wrong, you're banned from Math.

    If you say a proof is wrong and it turns out you are wrong, you're banned from Math.

    This is not a published paper. It is being reviewed now to determine whether it should be published. That's partially why peer-review exists in the first place. Mochizuki just made his opus available to other mathematicians so that they can determine whether it makes sense to them. That's how research works.

    --
    "What lies behind us, and what lies before us are tiny matters compared to what lies within us." Ralph Waldo Emerson
  14. Re:The people wrong must be banned from Math by UperPoti · · Score: 1

    On the one hand, I would like to give Peter and Jacok a big round of applause for taking the time to understand and publish the error in the original publication (shoveling stool). On the other hand, even though it is still possible that there may be a solution if Mochizuki was really that confident to have claimed to have the solution instead of asking for review, then given what I know about Japanese culture I would be more worried that Mochizuki is heading towards Aokigahara right about now than the possibility that he could be somehow "banned" from submitting a PDF to the interwebz.

  15. A line of reasoning near the end of the proof... by nuckfuts · · Score: 1

    In their report, Scholze and Stix argue that a line of reasoning near the end of the proof of "Corollary 3.12" in Mochizuki's third of four papers is fundamentally flawed.

    I am definitely incapable of reading Mochzuki's proof, but it would have been interesting if the article had cited the line in question.

  16. Re:The people wrong must be banned from Math by sexconker · · Score: 1

    If you actually read Einstein's original journals, you'll find that it's about the subjugation of the working class.

  17. Re:The people wrong must be banned from Math by hcs_$reboot · · Score: 1

    Ban is too strong. Right: +10 points, wrong: -2

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  18. Re:The people wrong must be banned from Math by hcs_$reboot · · Score: 1

    ...and everyone wrong here should be banned on slashdot?

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  19. Re:A line of reasoning near the end of the proof.. by hcs_$reboot · · Score: 2

    Well, to comprehend page 500 you have first to understand the 499 previous pages, which is why the flaw "near the end" is hard to spot.

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  20. ABC conjecture by rossdee · · Score: 1

    Have NBC and CBS confirmed it?
    How about CNN?

  21. Re:The people wrong must be banned from Math by Trogre · · Score: 1

    All of it or none of it?

    FTFY

    --
    "Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
  22. Re:The people wrong must be banned from Math by AchiestDragon · · Score: 1

    re quote "So... Einstein would have been banned from theoretical physics using your rules. His original theory of Special Relativity was wrong in some cases, so we got "general" relativity as a correction... With your rules we would have banned him." no theoretical physics is what it says on the tin theoretical , you could come up with a theory that the universe is just a magnified representation of a bacteria that resides in the gut , and it would still be valid theoretical physics , then its up to scientists to ether prove or disprove the theory , if proven it becomes science fact if not then try again , that's how theoretical physics works , but for science to say its this or that then you would be banned for giving false or inacurate results that you declared as facts not theory

  23. Re:The people wrong must be banned from Math by Calydor · · Score: 1

    You have just created the best incentive ever to NOT say that something is wrong even if you're 99.9% sure it is.

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  24. Re:The people wrong must be banned from Math by tehcyder · · Score: 1

    ...and everyone wrong here should be banned on slashdot?

    *tumbleweed*

    --
    To have a right to do a thing is not at all the same as to be right in doing it
  25. Re:The people wrong must be banned from Math by bobbied · · Score: 1

    I could live with that, if folks where actually keeping score.

    Personally, I'd give points for coming up with a theory and trying to prove it correct without resorting to deception, even if you are eventually shown to be wrong. Such things happen, folks propose ideas which turn out to be bad all the time; it's part of the process. My issue is when folks propose bad ideas, then insist they must be true and resort to lying and deception to gain notoriety. If you are honestly trying, great, if you are not being honest about the idea's problems, then that's bad.

    So, being credited with coming up with a theory that proves true is good for positive points based on the importance of the theory. If you propose a theory that turns out to be false, then that's neither good or bad. If you propose a theory and make grandiose claims in the press then use your notoriety to bury competing theories or those who are pointing out flaws in your theory, THEN I'm likely to be done with believing your claims until independently verified.

    --
    "File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
  26. Faith? by blindvic · · Score: 1

    So, if in a statement (theorem) nobody spots an error, it's considered proven and true? I wonder how many such theorems are out there in which we have faith?

  27. Re:The people wrong must be banned from Math by DRJlaw · · Score: 1

    If you come up with a proof and it's wrong, you're banned from Math.

    If you come up with an idea and it's wrong, you're banned from Ideas.

    *BANNED*