[HN Gopher] Mathematicians hunting prime numbers discover infini...
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       Mathematicians hunting prime numbers discover infinite new pattern
        
       Author : georgecmu
       Score  : 126 points
       Date   : 2025-06-19 03:28 UTC (2 days ago)
        
 (HTM) web link (www.scientificamerican.com)
 (TXT) w3m dump (www.scientificamerican.com)
        
       | wewewedxfgdf wrote:
       | This sort of thing makes me feel there is some deep understanding
       | of reality only inches away from us, we glimpse it through these
       | patterns but the secret remains hidden.
        
         | freed0mdox wrote:
         | and it will be something so trivial and obvious, those who were
         | looking for it will be kicking themselves for missing it
        
           | seanmcdirmid wrote:
           | It's a huge refrain that shows up again every 20 years or so.
           | Wolfram wrote a huge book with this premise, but I don't
           | think it's gone anywhere even though it's surely 25 years old
           | by now.
        
             | burnt-resistor wrote:
             | GEB was similar in a cycle prior. It's cool to dream but
             | the limits of accepted knowledge requires the hard work of
             | assembling data, evidence, and reasoning.
        
             | A_D_E_P_T wrote:
             | It's arguably ~2500 years old, dating back to the
             | Pythagoreans, who believed that "all is number" and had a
             | very large and complex system of musical rituals.
             | 
             | The modern manifestation is mostly the intellectual product
             | of Konrad Zuse, who wrote "digital physics" in 1969.
             | 
             | > https://en.wikipedia.org/wiki/Digital_physics
             | 
             | Wolfram, Tegmark, Bostrom, etc. are mostly downstream of
             | Zuse.
        
             | Kaijo wrote:
             | Wolfram came to our evolutionary biology department to
             | preach that book about 20 years ago. We all got our heads
             | into cellular automata for a while, but in the end they
             | just don't have the claimed profound explanatory power in
             | real biological systems.
        
             | robin_reala wrote:
             | You can read it for free at
             | https://www.wolframscience.com/nks/ if you're interested.
        
           | e1ghtSpace wrote:
           | honestly this would be it, wouldn't it?
           | https://www.icloud.com/iclouddrive/07fRJGiC51VEHPqYRfNaFjnEA
        
             | lukan wrote:
             | Did you tried to share a hollywood action movie with us to
             | tell us what exactly?
        
               | e1ghtSpace wrote:
               | Did you listen? The audio is different yet it still
               | works.
        
               | lukan wrote:
               | No, I did not download a big movie and likely won't to
               | get a point on HN.
        
               | e1ghtSpace wrote:
               | All you want is points on HN when you comment? Anyway,
               | try to only focus on the top middle screen in this video.
               | https://www.youtube.com/watch?v=T_dLx_J2oVs
        
               | lukan wrote:
               | Your point of argument/information. Not karma points.
        
           | amelius wrote:
           | Or someone proves that there is no pattern and they will be
           | kicking themselves for wasting their time searching.
        
             | mensetmanusman wrote:
             | The experience gained along the journey is more valuable
             | than the result.
        
         | waltbosz wrote:
         | Wouldn't it be fun if someone out there already knows a simple
         | way to determine if a number is prime without factoring, but to
         | them it is so obvious that they didn't even consider others may
         | be interested.
        
           | vasvir wrote:
           | Well I have a really elegant proof for this but I don't have
           | enough space in the HN reply box to write it out -- but it is
           | trivial, I am sure you will work it out.
           | Fermat Reincarnation.
        
           | kevinventullo wrote:
           | As far as I know, the Lucas-Lehrer test used by GIMPS does
           | not actually factor: https://en.m.wikipedia.org/wiki/Lucas%E2
           | %80%93Lehmer_primali...
        
             | Someone wrote:
             | That works for very few numbers. From that Wikipedia
             | article: _"In mathematics, the Lucas-Lehmer test (LLT) is a
             | primality test for Mersenne numbers"_
             | 
             | That's fine for GIMPS, which only searches for Mersenne
             | primes, but doesn't work in general.
             | 
             | https://en.wikipedia.org/wiki/Primality_test#Fast_determini
             | s... mentions several tests that do not require
             | factorization, though.
        
           | throwaway81523 wrote:
           | Pseudoprime test usually works, and AKS algorithm always
           | works, both are much faster than factoring.
        
           | adgjlsfhk1 wrote:
           | Since 2002 this has been known, and it's one of the least
           | intuitive things in modern math. (versions with probability
           | of 1-\epsilon have existed since Miller-Rabin in 1976)
        
         | briffid wrote:
         | I had a similar feeling. But I think this is indeed a glimpse
         | to the intrinsic structure of reality itself, not just a
         | promise of seeing reality. Like we can have a blink of turning
         | around in Plato's cave. I think the patterns of the Mandelbrot
         | set is a similar thing. And there are only a handful of other
         | things that shows the very basic structure of reality. And the
         | encouraging thing is that it seems the core of reality is not
         | an infinite void.
        
         | dcow wrote:
         | I don't think this understanding will be related to the
         | structure of reality but instead the structure of discrete
         | math. Math is not an observed property of reality it's a system
         | of describing quantities and relations between them, often with
         | plenty of practical application. Math is applied philosophy and
         | physics is applied math.
        
           | bmacho wrote:
           | Discrete math is the single most "observed property of
           | reality", and nothing else comes even close.
        
             | swayvil wrote:
             | I for one never saw a "number 2" in the wild. But I'm a
             | homebody.
        
               | curtisblaine wrote:
               | I guess you saw two things in the wild though.
        
               | alphazard wrote:
               | If I handed you 1 apple, and then handed you another
               | apple, you wouldn't be surprised to find that you had 2
               | apples. The same trick works with oranges and pears.
        
               | verzali wrote:
               | But not necessarily with rabbits. Can easily end up with
               | dozens of 'em when you ony started out with two.
        
               | brookst wrote:
               | Whoa
        
               | FredPret wrote:
               | > If I handed you 1 apple,
               | 
               | At this point I hold one object that we agree to label
               | "apple". Note that even seeing it as a single object is a
               | layer of abstraction. In reality it's a clump of
               | fundamental particles temporarily banding together
               | 
               | > and then handed you another apple,
               | 
               | What's "another apple"? What does it have in common with
               | the thing I'm already holding? We label this thing to be
               | also an apple, but it's a totally different set of atoms,
               | from a different tree, perhaps from the other side of the
               | planet. Perhaps the atoms formed in stellar processes
               | light years away from that of the other apple.
               | 
               | Calling both of these things "apple" is a required first
               | step to having two of them, but that is an of
               | abstraction, a mental trick we use to simplify the world
               | so we can represent it in our minds.
               | 
               | I'm not a particle physicist but I hear electrons *can*
               | be counted without any unwitting help from our lower-
               | level neural circuitry.
        
               | swayvil wrote:
               | I wouldn't even go with particles. I'd call it a stream
               | of sensations.
        
               | swayvil wrote:
               | There are a dozen leaps of abstraction occuring before
               | you arrive at "2 apples".
               | 
               | You are differentiating, classifying, etc.
        
               | pixl97 wrote:
               | Zero, one, infinity.
        
               | datameta wrote:
               | Infinity, aka 2 or more. I agree that those are truly
               | three distinct classes of quantity/identity
        
               | konfusinomicon wrote:
               | bears shit in the woods so they're out there if you look
               | in the right place
        
               | ndsipa_pomu wrote:
               | I've never seen gravity, but here I am, stuck to the
               | ground
        
             | hausrat wrote:
             | The very notion of discreteness depends on subjective
             | definitions of "objects". We take concepts of objects for
             | granted because they make interacting with the world
             | tractable, but it's really hard to define them outside of
             | minds.
        
               | yunwal wrote:
               | As far as we know, the universe is made up of discrete
               | units and any other type of math is an abstraction over
               | discrete math.
        
               | giardini wrote:
               | As far as we know, the universe is a single unity, and
               | any discrete units and any other type of math are human
               | distinctions overlaid upon that unity.
        
               | random3 wrote:
               | Can you explain what you mean here? I mean yes there's a
               | universe so it can be see as a unit. There's also quantum
               | mechanics, telling us we can only distinguish discrete
               | objects at the bottom of the scale. Can you give an
               | example of a non-human distinction, or explain what you
               | mean by that concept?
        
               | Keyframe wrote:
               | I thought it was a smooth continuous manifold
        
               | datameta wrote:
               | To what extent are the Planck length and Planck second
               | confirmed smallest discrete units?
        
               | Keyframe wrote:
               | I was referring to spacetime in GR is modeled as smooth
               | continuous manifold. In case you're serious though,
               | planck length are not some fine-grained pixels/voxels in
               | the cartesian 3d world, at least not confirmed; in-fact
               | planck units are derived scales.
        
               | feoren wrote:
               | No, discrete math is exactly the same regardless of your
               | definition of "object". It is completely _independent_ of
               | that. Discrete math is important to any theoretical
               | beings that have any concept of  "objects" whatsoever. It
               | would be mostly irrelevant to entities that have no such
               | conception, but those entities are not writing math
               | papers.
        
               | random3 wrote:
               | No, the discreetness comes from physical experiments. I
               | do see a problem defining something outside of one's mind
               | or outside the universe though :)
        
           | swayvil wrote:
           | Even counting and measurement are contrived abstractions. If
           | any big ultimate truth is delivered it will probably be
           | referring to our psychology.
        
           | m3kw9 wrote:
           | Math defines all that we do. Why do we want more? Because of
           | addition.
        
       | andsoitis wrote:
       | https://archive.is/2025.06.17-194128/https://www.scientifica...
        
       | gnabgib wrote:
       | Paper: https://www.pnas.org/doi/10.1073/pnas.2409417121
       | (https://news.ycombinator.com/item?id=44323658)
        
       | Sniffnoy wrote:
       | I'm a little confused at the significance here. Before I read the
       | definition of the M_a, this seemed crazy, but on actually reading
       | it, M_1 is just the sum-of-divisors function (usually denoted
       | sigma).
       | 
       | So, n is prime iff M_1(n)=n+1. That's much simpler than the first
       | equation listed there!
       | 
       | Indeed, looking things up, it seems that in general the functions
       | M_a can be written as a linear combination (note: with polynomial
       | coefficients, not constant) of the sigma_k (sigma_k is the sum of
       | the k'th power of the divisors). So this result becomes a lot
       | less surprising once you know that...
        
         | bubblyworld wrote:
         | Can you elaborate? How does this result become less surprising
         | if you know that? Personally I would not have guessed that
         | there are infinitely many characterisations of P involving
         | sums-of-powers-of-divisors either.
        
           | Sniffnoy wrote:
           | I mean, if you can do something a simple way, it's not that
           | surprising that you can also do it a complicated way, I'd
           | say.
        
         | isaacfrond wrote:
         | The M functions are the MacMahon's partition functions (see the
         | paper [1]). They were not known to relate to the sum of
         | divisors. The M_a function counts partitions in a parts but
         | weighing multiplicities in the partion.
         | 
         | [1]: https://arxiv.org/abs/2405.06451
        
           | boothby wrote:
           | Sorry, but M_1 is simply the sum of divisors, and I don't
           | think that was ever a mystery. Specializing the notation from
           | the paper for M_a, to a=1, and writing pythonic with finite
           | bounds for clarity...                 M_1(n) = sum(         m
           | for m in range(1, n+1)         for s in range(1, n+1)
           | if m*s = n       )
        
           | Sniffnoy wrote:
           | M_1 is obviously just sigma. That's straight from the
           | definition, you can't tell me that wasn't known.
           | 
           | As for the higher ones, I'm having trouble finding a proper
           | citation saying that this was known earlier, but this
           | math.stackexchange answer asserts that MacMahon himself
           | worked some of this out:
           | https://math.stackexchange.com/a/4922496/2884 No proper
           | citation though, annoying.
           | 
           | When you say "this wasn't known", on what basis is that? It's
           | very hard to be sure that something wasn't known unless
           | you're an expert on that particular thing!
        
         | boothby wrote:
         | I agree that the observation "M_1(n) = n+1 iff n is prime" is
         | elementary. It certainly motivates some intuition behind the
         | investigation in this paper, but I'd loathe to call it obvious.
         | 
         | Note that the paper studies equations with polynomial
         | coefficients on McMahon series. That is, the _n+1_ in our
         | trivial observation is  "stray" in a sense.
         | 
         | For an at-a-glance indication of nontriviality, look no further
         | than the conjecture associated with Theorem 1.2 -- that there
         | are exactly five equations of this sort which are prime
         | indicators. That seems spooky, to me; I can't help but wonder
         | what structure underlies such a small number of relations.
        
       | anthk wrote:
       | Prime generating functions in polynomials? That's almost Lisp
       | domain.
       | 
       | Mathematicians should play with Scheme and SICP.
        
       | swayvil wrote:
       | Yeah but can we get a pretty picture out of it? A cool fractal is
       | worth a thousand words.
        
       | nprateem wrote:
       | Oh. (3n3 - 13n2 + 18n - 8)M1(n) + (12n2 - 120n + 212)M2(n) -
       | 960M3(n) = 0.
       | 
       | I'd have thought that was obvious.
        
       | drdunce wrote:
       | This have implications for public key cryptography?
        
         | datameta wrote:
         | My naive notion on this is yes, iff the new method is
         | computationally or memory-wise of lower complexity
        
         | boothby wrote:
         | Computing M_a(n) appears to be at least as hard as factoring n
         | for a=1, so I think you're safe here.
        
       | ysofunny wrote:
       | I hope the twin prime conjecture will become a theorem during the
       | remainder of my lifetime
       | 
       | that's why I already got the double twin prime conjecture ready:
       | 
       | there exists an infinite number of consecutive twin primes. 3
       | examples: 11,13; 17,19. 101,103;107,109, AND 191,193;197,199... I
       | know of another example near the 800s
       | 
       | there's also the dubious, or trivial, or dunno (gotta generalize
       | this pattern as well) of the first "consecutive" twin prime but
       | they overlap which is 3,5 and 5,7.... which reminds me of how
       | only 2 and 3 are both primes off by one; again, I need to
       | generalize this pattern of "last time ever primes did that"
        
         | D-Coder wrote:
         | BTW the phone number in Jenny's song, 867-5309, is a twin prime
         | (867-5311).
        
           | jsisto wrote:
           | Twin towers prime 9/11
        
         | adgjlsfhk1 wrote:
         | The broader generalization you're headed towards is
         | https://en.wikipedia.org/wiki/Dickson%27s_conjecture (or the
         | even more general
         | https://en.wikipedia.org/wiki/Schinzel%27s_hypothesis_H) which
         | basically say that the twin prime conjecture is true for every
         | linear/polynomial generalization of twin primes.
        
         | zck wrote:
         | > there's also the dubious, or trivial, or dunno (gotta
         | generalize this pattern as well) of the first "consecutive"
         | twin prime but they overlap which is 3,5 and 5,7.... which
         | reminds me of how only 2 and 3 are both primes off by one;
         | again, I need to generalize this pattern of "last time ever
         | primes did that"
         | 
         | For the triplet n, n+2, n+4, exactly one of those numbers is
         | divisible by 3. So the only triplet n, n+2, n+4 where all
         | numbers are prime contains 3: 3, 5, 7.
        
       | munichpavel wrote:
       | Ken Ono, one of the authors, is the mathematician behind the
       | University of Virginia women's swimming team's dominance in
       | recent years, including world records and gold medals.
       | 
       | https://news.virginia.edu/content/faculty-spotlight-math-pro...
        
       | noqc wrote:
       | Because the article doesn't actually say so (presumably because
       | the author doesn't know the difference between "if" and "if and
       | only if") the statement:
       | 
       | (3n^3 - 13n^2 + 18n - 8)M_1(n) + (12n^2 - 120n + 212)M_2(n) -
       | 960M_3(n) = 0
       | 
       | is _equivalent_ to the statement that n is prime. The result is
       | that there are infinitely many such characterizing equations.
        
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