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60-Year-Old Maths Problem Partly Solved By Amateur (theguardian.com)

An amateur mathematician has made the first breakthrough in more than 60 years towards solving a well-known maths problem. From a report: Aubrey de Grey, who is more widely known as a maverick biologist intent on extending the human lifespan, has taken the academic world by surprise after announcing a new solution to the so-called Hadwiger-Nelson problem. The problem sounds deceptively simple, but despite some professionals spending years trying to crack it, progress has stalled since shortly after the puzzle was first posed in 1950. "Literally, this is the first progress in more than 60 years," said Gil Kalai, a mathematician at Hebrew University of Jerusalem.

The problem is as follows. Imagine a collection of dots connected by lines. The dots can be arranged any way at all, the only rule is that all the connecting lines must be of equal length. For instance, in a square the diagonal would not be joined up, but the outer edges would be. Now, colour in all the dots so that no two connected points have the same colour. How many colours are required. For a square, the answer would be two. But the Hadwiger-Nelson problem asks what the minimum would be for any configuration -- even one that extends across a plane of infinite size.

29 of 161 comments (clear)

  1. Correct Wikipedia Link by zmaragdus · · Score: 5, Informative
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    (((dB)))
    1. Re:Correct Wikipedia Link by tonique · · Score: 2

      Wikipedia uses, in its infinite wisdom, the character U+2013 (en-dash) in article names like those. You get the correct link to the article with decoded characters when you copy the link from the tab heading "Article" at the top of the article. It shows the en-dash as %E2%80%93, as it should.

  2. Not quite by Anonymous Coward · · Score: 3, Informative

    If you read the articles, he pushed the instance of contradictory evidence from N=4 to N=5, but has no proof that N=6 isn't a instance.

    Thus, it is a new piece of evidence that N>=5, but not that it is solved.

    1. Re:Not quite by NicknameUnavailable · · Score: 5, Informative

      He did limit the potential solution space by 25% - that's not nothing, it was known to be 4-7, now it's known to be 5-7.

  3. Professional just means you get paid... by Kenja · · Score: 2, Insightful

    it does not mean you're any good at what you do.

    --

    "Have you ever thought about just turning off the TV, sitting down with your kids, and hitting them?"
    1. Re:Professional just means you get paid... by TechyImmigrant · · Score: 2

      He gives a pretty good talk too:
      https://www.youtube.com/watch?...

      --
      I should use this sig to advertise my book ISBN-13 : 978-1501515132.
  4. Mathematical collaboration by tgibson · · Score: 4, Informative

    Aubrey De gray's finding has the attention of the Polymath Project, "a collaboration among mathematicians to solve important and difficult mathematical problems by coordinating many mathematicians to communicate with each other on finding the best route to the solution."

    You can follow their current conversation here.

    1. Re:Mathematical collaboration by deesine · · Score: 2

      Interesting, according to Aubrey "I got lucky and [Dan P. Ismailescu] got unlucky". Also, the "problem was ripe for the picking. And while we like your proof better, we are very happy that ours is different." says Dan P. Ismailescu about teaming with Geoffrey Exoo for three years. Refreshing the respect these guys show each other.

      Think I'm done reading /. today, thanks for the link.

      --
      damaged by dogma
  5. Re:Jesus by jellomizer · · Score: 4, Insightful

    It could, the geometric shape can be abstracted into other things. Such as time, and process, I could see this being used to help optimize a parallel programming process where a particular code takes so long to run, but to avoid collisions the different elements in time, will need to hit different process points at different time, then you need to span it up, so how many unique process points will you need. Say with a massively parallel system, such as an advanced quantum computer.

    --
    If something is so important that you feel the need to post it on the internet... It probably isn't that important.
  6. Re:why the s? by alvinrod · · Score: 3, Informative

    It's the British English spelling, which makes sense given the story is from the Guardian. I guess we could squabble about whether maths or math is more appropriate, but they're both contractions of mathematics.

  7. Actual article and news. by will_die · · Score: 5, Informative

    https://www.quantamagazine.org...

    Is the article article about what was done, not the cut down version from a gossip rag sheet which is given in the summary.

  8. Maverick science is just getting started by paradigmsareconstruc · · Score: 2

    Big Science and maverick outsiders can actually greatly benefit from each others' existences, for the mavericks are free to ask questions which might be out-of-bounds in academic circles -- and so, they are much better positioned to start new groundbreaking lines of investigation. We can solve the publish-or-perish problem with this exact approach, but it will require us to care more about long-term innovations than our short-sighted desires to confirm our pre-existing worldviews.

    The top-down philosophical approach of specialist science has left us with a sort of vacuum of tools to support the outsider maverick thinkers. To the extent that it is acknowledged that outsiders can contribute in important ways, we will inch closer to creating these tools.

    1. Re:Maverick science is just getting started by gtall · · Score: 2

      "they are much better positioned to start new groundbreaking lines of investigation" I do not think so. Science these days requires lots of years of experience. You get the one or two odd contributions from outsiders, but largely scientific progress is made in the trenches slogging it out year after year. Care to explain any advances in string theory due to outsiders to physics?

    2. Re:Maverick science is just getting started by lgw · · Score: 2

      Well, I don't know how generally true that is, but certainly in Math there is a class of old, unsolved problems that professors don't want to be seen as working on, as they are assumed to be a waste of time and thus it's somewhat embarrassing to be working on them. Obviously, that concern doesn't apply to anyone who doesn't have "math professor" as their day job.

      --
      Socialism: a lie told by totalitarians and believed by fools.
  9. To expand on the summary by JoshuaZ · · Score: 2

    It was well known that one never needs more than 7 colors- this comes from a little work where one can tile the plane with hexagons and then pick 7 distinct colors cleverly. It was also known that you needed at least 4 colors, since one can construct configurations which require 4 colors. Both of these parts are simple enough that working out the details are fun exercises. What Aubrey de Grey did is use a careful construction involving certain specific subconfigurations to aid a computer search to construct a very big configuration which was highly likely to need 5 colors; he then verified using a computer system that this configuration did require 5 colors. But note that while this is progress this isn't a full solution; this shows that the number of colors needed is at least 5, but whether it is 5,6 or 7 is unclear. My own guess based on his work is tentatively towards 6 because it looks like there's a lot of room in his configuration that might allow one to bump it up to 6 with a few more ideas and the argument for why one needs at most 7 is so simple that it seems like something should be able to reduce that even if no one has figured it out yet.

  10. Who cares about "amateur" status by sjbe · · Score: 2, Informative

    An amateur mathematician has made the first breakthrough in more than 60 years towards solving a well-known maths problem.

    Why is it relevant whether he gets paid to solve mathematical problems or not? Amateur just means that someone doesn't derive any income from the task. It has nothing to do with competence or the lack thereof. Plenty of people are very talented at things they don't get paid for.

    1. Re:Who cares about "amateur" status by ChrisMaple · · Score: 2

      It's relevant because someone paid to do mathematics is presumed to have the time, inclination, motivation, and ability to advance the field. An amateur is presumed to only be able to work on problems in his scant spare time, with a mind trained to handle problems in another field. This implies either that the amateur is a truly superior intellect or that the professionals are slackers.

      Not correct, of course, but it's similar to rooting for the underdog.

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  11. Re:four color theorem? by nasch · · Score: 2

    Perhaps this could lead to a proof for the somewhat similar four color theorem?

    No need.

    "The four color theorem was proved in 1976 by Kenneth Appel and Wolfgang Haken... To dispel remaining doubt about the Appel–Haken proof, a simpler proof using the same ideas and still relying on computers was published in 1997 by Robertson, Sanders, Seymour, and Thomas. Additionally, in 2005, the theorem was proved by Georges Gonthier with general-purpose theorem-proving software."

    https://en.wikipedia.org/wiki/...

  12. Re:N=6 by sysrammer · · Score: 2

    We all know when using graphs at the large scale every shit is converging towards number 6.

    As proven by the "Kevin Bacon Six Degrees of Separation" theory.

    --
    His ignorance covered the whole earth like a blanket, and there was hardly a hole in it anywhere. - Mark Twain
  13. Re:why the s? by NicknameUnavailable · · Score: 2

    It's the British English spelling, which makes sense given the story is from the Guardian. I guess we could squabble about whether maths or math is more appropriate, but they're both contractions of mathematics.

    As long as we can agree that the British don't belong in the American internet I think we're all on the same page.

  14. New lower bound identified by Anonymous Coward · · Score: 2, Informative

    Essentially, it has been known for a while that the answer is either 4 or 5 or 6 or 7.

    This paper identifies a graph that cannot be colored with just 4 colors, so it establishes 5 as the new lower bound.

  15. Re:Jesus by gtall · · Score: 4, Insightful

    Hmmm...lemme guess, when Evariste Galois was inventing group theory, you'd be in the peanut gallery claiming you couldn't see any use for it (hint, he did it in the early 1800s). And when those wild and crazy guys were screwing up developing the math for quantum mechanics, you'd be asking them for a practical use (hint, they did it in the early 1900s).

    In short, if someone cannot point to a use of something, it shouldn't be done. How enlightened of you? Have you explained your theory to scientists? I'm sure they'd listen to you.

  16. Re:It would be a wonderful world by Ghostworks · · Score: 4, Informative

    There's no reason to argue... it's actually pretty easy to explain how the (modern) English are wrong:

    Separated by a Common Language: Math(s)

    The British often linguistically treat "mathematics" as though were the plural of some noun "mathematic". But the -s is the nominative -s.

    How do we know that these are really different affixes, and not just the same affix doing a range of jobs? Partly we know from history. The plural -s comes from an Old English case suffix (-es or -as). The verb one has derived from the suffix -eth (or -ath) in earlier Englishes. The adverbial one is related to the possessive 's. And our friend the nominali{s/z}ing (=noun-making) suffix generally affixes to roots from classical Greek.

    It's easy to find other uses of the nominative -s -- for example, almost any high-level subject of study such as mechanics, physics, economics, linguistics -- but now many are long and common enough to be frequently abbreviated by common people. For example, few people talk about "economics" often enough to shorten it to "econ" or "econs" (though when they do, it's usually "econ").

    This also is one of the cases that led me to rule of thumb "(modern) English people can't speak English". Americans seem to hang on to the "old way" of speaker longer than the British do.

  17. Re:It would be a wonderful world by arth1 · · Score: 2

    The British often linguistically treat "mathematics" as though were the plural of some noun "mathematic". But the -s is the nominative -s.

    Yes, as you say mathematics, like pyrotechnics, the s is an integral part of the noun, and not a plural. It comes from Greek -ikos.

    Exceptions exist, like "music" which perhaps should have been musics (from mousikos), given that the (once synonymous) technikos became technics.
    On the other hand there is "chiropractic", where the name is as made up as the practice, and it doesn't have an s at the end.

  18. Re:hmmm by lgw · · Score: 2

    No matter how much sense a definition makes in your own head, that's not how language works.

    --
    Socialism: a lie told by totalitarians and believed by fools.
  19. Re:hmmm by lgw · · Score: 2

    Only in the same way that math is a subfield of biology, since it's done by humans.

    He's not paid to publish math papers, is the point.

    --
    Socialism: a lie told by totalitarians and believed by fools.
  20. Re:Jesus by mikael · · Score: 2

    That would be Hilbert space filling curves. Those are used to optimize parallel processing. Also used in a way to arrange the folding of the brain so that every region is a minimum distance from the spinal cord and optic nerves.

    --
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  21. Re:3D is infinite - rough argument by wisnoskij · · Score: 2

    Exactly, but don't we have a countable number of rotations, therefore necessitating a countable solution?

    But I am starting to see why this problem is so hard. If i understand it correctly, dots can be any distance apart, it is just that the ones equal distance apart have lines.

    So the solution is probably not a pretty looking pattern, where all neighbor dots are equal distance but instead a bloody mess of thousands of patterns overlapping each other and all you can see is chaos.

    --
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  22. Re:2D is the hard question by slew · · Score: 2

    In 3D the number most likely jumps to infinity. This is like the how many colours does it take to colour a map so that no adjacent countries have the same colour. 1D is trivally 2, 2D is four but the proof sucks, 3D is clearly infinity.

    Although it might be tempting to "analogize" the problem the 4 color map problem, in fact the problems are not at all similar and have a different answer.

    Even, the wikipedia entry on this problem has an answer to this particular generalization to 3D...

    The problem can easily be extended to higher dimensions. In particular, finding the chromatic number of space usually refers to the 3-dimensional version. As with the version on the plane, the answer is not known, but has been shown to be at least 6 and at most 15.

    This is a pointer to paper the illustrates the upper bound for R^3 in case you are interested.