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There Are Infinitely Many Prime Twins

fustflum writes "R. F. Arenstorf from Vanderbilt University has presented a 38-page possible proof of the twin-prime conjecture using methods from classical analytic number theory. The paper is on arxiv.org and is freely available to the public. Twin primes are pairs of primes where both p and p + 2 are prime. "It is conjectured that there are an infinite number of twin primes ... but proving this remains one of the most elusive open problems in number theory." More information about twin primes can be found on Mathworld."

85 of 479 comments (clear)

  1. Number theory by PHP+Wolf · · Score: 5, Funny
    but proving this remains one of the most elusive open problems in number theory

    I think we all know the most elusive open problem in number theory is "How many licks does it take to get to the center of a tootsie pop?"

    --

    Double Compile

    1. Re:Number theory by DarkHelmet · · Score: 3, Funny

      Let's leave the proof to Physics:

      One... two... three... *BITE*

      ............Three.

      --
      /^[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,4}$/i
    2. Re:Number theory by Da+Fokka · · Score: 5, Funny

      Reminds me of a funny story I heard at an algorithm course in college.
      Supposedly this guy thought up this new algorithm to calculate large primes in relatively short time. He was granted the use of the university mainframe. He implemented the progam and ran it.
      After a couple of days the printer started printing out the number, which was so large it needed a pack of sheets to fit on.
      Excited, he looked at the sheets to be gravely disappointed. The last digit was an 8.

      Probably an urban legend, but a nice one for sure :)

    3. Re:Number theory by drinkypoo · · Score: 2, Funny
      It probably did happen, but he wrote the bytes out to the file in endian-order a word at a time rather than using sequential bytes, and the last two digits were transposed...

      A story like that can never be true unless it is ultimately cruel.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    4. Re:Number theory by drinkypoo · · Score: 4, Funny
      By making what has to be approximately the eleventy-teenth reference to the HHGttG you have only made slashdot a more trite place.

      Put another way, you have entirely failed to receive a wrapper depicting an indian shooting a star.

      --
      "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
    5. Re:Number theory by sbaker · · Score: 3, Interesting

      My son figured this out - with the help of some Lego - the answer is 332 (except for the Cherry ones that take a few less):

      http://www.sjbaker.org/gallery/lickomatic/index.ht ml

      --
      www.sjbaker.org
  2. One smart dude by overbyj · · Score: 4, Informative

    I was a grad student at Vanderbilt in a different department but I had some friends in math that really knew this guy. Needless to say, this guy is brilliant. I don't really know much about his work but honestly, I am surprised it took him as long as it did to do this.

    Score another for number theory thanks to this dude.

    --
    No trees were harmed in the composition of this; however, numerous electrons were inconvenienced.
    1. Re:One smart dude by fatphil · · Score: 5, Insightful

      Slow down!
      It's not been reviewed yet.

      I'm waiting until Granville, Odlyzko, Mihailescu, or someone similar gives it the thumbs up.
      However, it's not obvious tosh, and therefore if it does have flaws it may well be correctible, or at least provide new insight.

      The guy certainly _was_ brilliant, but given that he started his peak in the mid-60s, there's no guarantee he's still at it.

      FP.

      --
      Also FatPhil on SoylentNews, id 863
    2. Re:One smart dude by PDAllen · · Score: 3, Insightful

      It's quite easy to write a program that will verify any proof written out in formal logic.
      The problem is that to write out any proof that isn't really obvious anyway in formal logic requires huge amounts of time and space (think 3000+ pages rather than 38, mainly proving the equivalent of 2+2=4).
      There are a few people trying to produce a language for mathematics that a computer can understand and check which isn't quite so completely painful and allows you to quote theorems; but they're still quite messy and most of the theorems you might want to use haven't been included yet.
      So people go for the time-honoured method of writing proofs in a way that makes sense to a human, and then having people check the logic by hand. Then you need someone who works in the same field to verify it, because people working in different fields won't know the theorems and would have to spend a year or so learning the background.
      The reason people don't want to assume something is true until it's been checked is that if you assume that X's proof of a theorem is valid, and you then produce a 200-page proof of the Riemann Hypothesis which assumes the theorem X said he'd proved, then someone checks X's proof and finds a mistake, your proof also collapses.

  3. This is why mathematicians are soooo popular. by The+I+Shing · · Score: 3, Funny

    This stuff is so fascinating that I'm just sure I'll be the life of the party when I start talking about it!

    "You know, mathematicians theorize that there's an infinite number of prime twins, and... hey, where are you going?"

    --
    You are in error. No-one is screaming. Thank you for your cooperation.
    1. Re:This is why mathematicians are soooo popular. by servognome · · Score: 5, Funny

      "You know, mathematicians theorize that there's an infinite number of prime twins, and... hey, where are you going?"
      You would have gotten farther if you had said that without staring the whole time at her "prime twins"

      --
      D6 63 0D 70 89 81 BB 8E 7B 7C 5F 5D 54 EA AB 73
  4. Old news by Hamster+Of+Death · · Score: 4, Funny

    Glancing at my list of twin primes I can see it's infinite.

  5. I have a better proof by Anonymous Coward · · Score: 5, Funny

    but it hit /.'s maximum post size limit :(

  6. Can someone buy the editors a dictionary by Timesprout · · Score: 2, Funny

    possible proof of the twin-prime conjecture

    The words possible and conjecture appear above. Where does the definitive statement "There Are Infinitely Many Prime Twins" come into it? Have the the /. editors secretly managed to prove this theory before posting it ?

    --
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    What truth?
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  7. 38 pages? by Wakkow · · Score: 5, Funny

    They should have put it in 37 pages..

    1. Re:38 pages? by Anonymous Coward · · Score: 2, Funny
      They should have put it in 37 pages..

      Yes 37 is prime, but 41 is the nearest *twin* prime (with 43). So they should add 3 pages.

  8. Well, one thing's for sure.. by robbo · · Score: 5, Funny

    they're all odd.

    (Waiting for my spot in the math hall of fame)

    --
    So long, and thanks for all the Phish
    1. Re:Well, one thing's for sure.. by philntc · · Score: 2, Informative

      erm. except one, 2.

    2. Re:Well, one thing's for sure.. by ronsonal · · Score: 3, Informative

      2 isn't a twin prime.

    3. Re:Well, one thing's for sure.. by Anonymous Coward · · Score: 2, Funny

      0/0 = 0 I was going to refute your post, but got a divide by zero error while thinking about it. Please be more careful next time.

    4. Re:Well, one thing's for sure.. by TheOtherChimeraTwin · · Score: 2, Insightful

      Two is the only even prime number, which certainly makes it odd.

    5. Re:Well, one thing's for sure.. by mblase · · Score: 2, Funny

      erm. except 2.

      And don't you find that a bit odd? *rimshot*

  9. Prime Arithmetic Progression also in the news by micha2305 · · Score: 5, Interesting

    Something I read in Science the other day: There's a new proof in review that there are infintely many sequences such as 199, 409, 619, 829, 1039, 1249, 1459, 1669, 1879, 2089 -- primes that differ by a constant offset. See also Mathworld.

    1. Re:Prime Arithmetic Progression also in the news by aardvarkjoe · · Score: 4, Informative
      Quoting directly from the linked article:
      An arithmetic progression of primes is a set of primes of the form p1 + kd for fixed p1 and d and consecutive k, i.e., {p1, p1 + d, p1 + 2d, ...}. For example, 199, 409, 619, 829, 1039, 1249, 1459, 1669, 1879, 2089 is a 10-term arithmetic progression of primes with difference 210.

      In a recently published in preprint, Green and Tao (2004) use an important result known as Szemerédi's theorem in combination with recent work by Goldston and Yildirim, a clever "transference principle," and 48 pages of dense and technical mathematics, to apparently establish the fundamental theorem that the prime numbers do contain arithmetic progressions of length k for all k (Weisstein 2004).

      Take it for what it's worth. This stuff is way over my head.
      --

      How can we continue to believe in a just universe and freedom to eat crackers if we have no ale?
  10. Calm down, boys ... by RealAlaskan · · Score: 4, Funny

    That's ``twin primes'', not ``prime twins''. So, no, there is not an infinite supply of hot double dates.

  11. Alien by Juiblex · · Score: 4, Funny

    In what Alien language is the article written???

  12. twins by sacrilicious · · Score: 4, Funny
    Twin primes are pairs of primes where both p and p + 2 are prime.

    Even rarer are those pairs of primes known as the "conjoined twin" primes: those of the form p and p+1. Not many examples are known, but perhaps an infinite number are waiting to be discovered.

    --
    - First they ignore you, then they laugh at you, then ???, then profit.
  13. Re:cursed mathmaticians by fatphil · · Score: 3, Insightful

    "Hopefully this new paper will have some good cryptographic applications"

    It won't. Sorry. Just like AKS, this is something that's entirely in the realm of the theoretical.

    FP.

    --
    Also FatPhil on SoylentNews, id 863
  14. Ugh... math... by gwoodrow · · Score: 3, Funny

    I tried to read through some of the paper and math websites... and I was suddenly reminded why the diploma that will be handed to me at the end of the summer will say:
    "Steven Gregory Woods... ENGLISH major"
    Hopefully, math will turn out to be just a fad :)

  15. Thank goodness! by DanielMarkham · · Score: 3, Funny

    Now I have something to use at the bars to pick up chicks this weekend! "Hey babe, I don't know how cute you think you are, but I know there are an infinite number of prime twins just waiting to factor this integer." That number theory talk always gets them interested.

  16. Re:I didn't RTFA by RackinFrackin · · Score: 2, Informative

    The fact that there are an infinite number of integers doesn't, by itself, imply the infinitude of the primes, the twin primes, or the perfect numbers. Seeing a bunch of them is good evidence, but
    in order to know that they are infinite, a proof is required. There are many proofs of the infinitude of the primes; there are an infinite number of perfect numbers, but this was not known for a fact until Euclid proved it. Thus far, no one has been able to produce a proof that there are infinitely many twin primes, and thus it is still at the conjecture stage. If this guy's proof is good, then it is definitely newsworthy.

  17. Lehrer by pjt33 · · Score: 4, Insightful

    Have you never heard of Tom Lehrer? If not, shame on you.

  18. Re:Proof by Jim+Starx · · Score: 2, Insightful

    Irrational numbers are mysterious as a whole, I don't think pi is special in that respect. The prrofs are fascinating though. Prooving incommensurability(sp?) takes some very creative thinking.

    --
    The darkness... controls the music. The music... controls the soul.
  19. we've known since 1761 by Anonymous Coward · · Score: 3, Informative

    we've known since 1761

  20. Re:I didn't RTFA by Geoffreyerffoeg · · Score: 4, Informative

    Because as numbers get higher, there are a lot more numbers below that can be factors, and thus the frequency of prime numbers decreases. E.g., between 1-10 we have 5 prime numbers, but between 1000-1030 there are only 4. This amusing animation that generates prime numbers demonstrates that prime numbers are more rare as you approach infinity (i.e., the program's "prime density" drops).

    Thus it would make sense that the probability of having a twin prime would drop. The question is if it drops to zero or not.

    It can be demonstrated that there are infinite primes, though, by saying that if there were a finite set of primes, you can get a new number by multiplying all the known primes and adding one. This number divided by any of the known primes always gives a remainder of one. Thus it has no prime factors, and is prime. We would then tend to believe there are infinite twin primes, but this is not so easily proven.

  21. Re:I didn't RTFA by Dominic_Mazzoni · · Score: 5, Informative

    OK, I'm too lazy to RTFA, but, if there are infinite numbers, why would there not be infinite prime numbers, and infinite prime twins? Are there also not infinite perfect numbers, or ...?

    That's a good question.

    The fact that there are an infinite number of numbers doesn't immediately imply that there are an infinite number of primes, but Euclid figured out how to prove this is true in about 300 BC. It only takes a few sentences to explain it; here's one example.

    It is definitely not obvious that there are an infinite number of twin primes. It has been an open question for more than a century, and some of the greatest minds in mathematics have worked on it. If this proof is correct, it will be a major result.

    I was trying to think of a good example of something that there is not an infinite number of. Browsing through MathWorld, I found Truncatable Primes - there are only 83 of these.

    Can anyone think of any other examples of a type of number that only has a finite number of them, even though at first glance it seems like there might be an infinite number of them?

  22. This took 20 years by ortholattice · · Score: 4, Informative
    Interesting quote from the paper (p. 3 of the PDF file):
    This work is the outcome of about twenty years of "on and off" search and research on this and the related binary Goldbach problem; in the interim having been lured onto various misleading paths or frustrated by (for me) insurmountable difficulties, before ultimately recognizing and constructing a workable approach.
  23. He makes a mistake... by b0r0din · · Score: 5, Funny

    Look on page 27. He's trying to integrate homeomorphic convergence using a Baxter-Bates supermodality, which Krause clearly explained is impossible for T(s) in a non-linear progression.

    Ok, just fuckin with ya. My mind wandered after I saw the word 'Abstract.' ;)

    1. Re:He makes a mistake... by Lord+Graga · · Score: 2, Funny

      I wonder if it's just me, or did a horde of really scary math geeks just mod that up? I sure didn't get it ;)

    2. Re:He makes a mistake... by Anonymous Coward · · Score: 5, Funny

      Yeah, I see a lot of people attempting to integrate homophobic conformance using Master-Bates supermoodality, which Krauds exploded as impenetrable for T/bag in a non-lesbian prostation.

    3. Re:He makes a mistake... by Theatetus · · Score: 2, Informative
      A nice thing to have: a computer program that knows many important theorems I1, I2, I3, ... so that the user can specify "apply I12" followed by an application of I19 and then I6 and so on. The program doesn't have to understand the theorems, just use them in a sequence of deductions, as directed by a mathematician.

      Yeah, it's amazing nobody ever thought of that.

      --
      All's true that is mistrusted
  24. I have a better proof, and it fits by Atario · · Score: 3, Funny
    1. Given: There are infinitely many primes.
    2. Given: A certain positive percentage of primes differ by two.
    3. Given: Infinity times any positive number is infinity.
    4. Therefore: There are infinitely many primes that differ by two.
    That's my story and I'm stickin' to it.

    (Spot the logical error and you win a cookie!)
    --
    "A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
    1. Re:I have a better proof, and it fits by hoggoth · · Score: 3, Insightful

      > 2. Given: A certain positive percentage of primes differ by two.

      Not necessarily true. It's equally possible that a certain finite number of primes differ by two, not an infinite percentage of primes.

      Give me my cookie now.

      --
      - For the complete works of Shakespeare: cat /dev/random (may take some time)
    2. Re:I have a better proof, and it fits by cubic6 · · Score: 3, Interesting

      You can't assume that a certain positive percentage of *all* primes differ by two as stated in number two, because that's an analogous statement to what you're trying to prove.

      Say I have an infinite number of socks. All are white, except 3, which are grey. I have a positive percentage of grey socks, but that doesn't mean anything since that percentage is infinitessimal. It will be infinitessimal for any number of grey socks, so you can't say that you are assumed have a positive percentage of grey socks *unless* you have an infinite number of grey socks, and that's a tautological argument.

      Chocolate chip, please ;)

      --
      Karma: Contrapositive
    3. Re:I have a better proof, and it fits by SashaM · · Score: 4, Informative

      It's equally possible that a certain finite number of primes differ by two, not an infinite percentage of primes.

      Talking about infinite percentages is meaningless. Think about this question - what percentage of all natural numbers are even? On the one hand, it seems that since every second number is even, there would be 50%, right? But what if I pair each and every natural number to an even number so that two different numbers are paired to different even numbers (a one-to-one map)? Would that mean that 100% of all natural numbers are even? But it is done easily - I would pair each number n to 2*n.

      You could try and wiggle out of this problem by defining the infinite percentage to be the limit of the normal percentage until N when N goes to infinity. This would work for some sets, like the even numbers and would even give you a seemingly reasonable answer - 50%. But then consider this question - what percentage of all natural numbers are powers of 2 by this definition? I'll leave that as an exercise to the reader :-)

      See Cardinality

    4. Re:I have a better proof, and it fits by SashaM · · Score: 3, Interesting

      Exactly, which is why that definition is no good either - there is an infinite amount of numbers which are a power of 2, so saying their percentage is 0% makes no sense, or conveys no interesting information. By that definition, an empty, a finite and even an infinite set could be 0% of all natural numbers.

    5. Re:I have a better proof, and it fits by SashaM · · Score: 4, Informative

      I'll explain it like my prof. did :-)

      Imagine you arrive at a party and see that some number of men and women are dancing in pairs - each woman is dancing with one man and each man with one woman. You can immediately observe, without counting the actual number of men and women that there is an equal amount of them, right? The same idea is applied to sets (even infinite ones) - if you can pair each element in set A to an element in set B in such a way that each element in B has a pair in A then the two sets have the same "amount" (cardinality is the mathematical term) of elements.

      Now, let's take A to be the set of all natural numbers and B to be the set of all even natural numbers. I will then pair each natural number n, to an even number - 2*n. Now, each even number N has a pair - N/2, so we conclude that the "amount" of even numbers equals the "amount" of natural numbers (100% of them, by the naive definition).

      You might conclude from this that any two infinite sets have the same "amount" of elements, which seems true at first glance - after all, infinity is infinite, so surely there will be enough elements in any infite set to pair to the elements of another infinite set! This, however, turns out to be wrong. For example, there are "more" real numbers than there are natural numbers. That is, there exists no one-to-one and onto function (Bijection) from the set of natural numbers to the set of real numbers.

    6. Re:I have a better proof, and it fits by Atario · · Score: 3, Funny

      Ding ding ding! We have a winnah!

      You will find your cookie on your hard drive, assuming you're logged in to Slashdot.

      --
      "A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
  25. Other Number Theory Tricks? by CoolGuySteve · · Score: 4, Interesting

    The sum of any two consecutive odd numbers is divisible by 4. I misread a question in first year and proved it.

    I thought that was fairly neat, it makes me the life of the party when I tell it to people. (Well, not really. Depressing.) Does anyone know any other little tricks like that?

    1. Re:Other Number Theory Tricks? by Anonymous Coward · · Score: 2, Insightful

      Well, duh -- (2n-1) + (2n+1) = 4n. ;^)

      Here's my neat math trick: Take a multiplication table and go down the diagonal with all the perfect squares. Take one step northeast or southwest on the grid, and the new number is always one less than the one you came from.

      The only person I told this to, however, pretty much replied "Well, duh -- (n-1)(n+1) = n^2 - 1."

    2. Re:Other Number Theory Tricks? by CoolGuySteve · · Score: 2, Informative

      Here's the proof because I'm bored.

      Any two consecutive prime numbers can be represented as e + 1 and e + 3 where e is an even number. Their sum is: (e + 1) + (e + 3) = 2e + 4. Because e is even, it's divisible by 2, so let o be e|2.

      So 2e + 4 = 2(2o) + 4 = 4o + 4 = 4(o + 1) which is divisible by 4. .`. the sum of any two consecutive odd numbers is divisible by 4.

    3. Re:Other Number Theory Tricks? by Jim+Starx · · Score: 3, Funny
      Here's an interesting one, this is guarenteed to piss off any math student that doesn't get it.

      if a=b, then:

      a^2=ab
      a^2-b^2=ab-b^2
      (a-b)(a+b)=b(a-b)
      a+b=b

      substitute in the original a=b equation

      2a=a
      2=1

      wtf? So where's the error? :)

      --
      The darkness... controls the music. The music... controls the soul.
    4. Re:Other Number Theory Tricks? by Sycraft-fu · · Score: 4, Informative

      "So where's the error?"

      I'm guessing that's a rhetorical question, but the error is you divide by zero. On line three you are actually are showing 0=0 since anything minus itself is zero and anything times 0 is 0. You then try to divide out (a-b), which is zero, and can't be done.

      I can see this fooling people who aren't good at math but probably not math students. It's not like I ever got very far in math, and the problem is easy to spot.

  26. You are either on crack or joking. by mcc · · Score: 2, Informative
    There are no "conjoined twin" primes other than 2 and 3. Rather trivial proof follows:
    • Assume p and p+1 to be primes, and p>2
    • Since p is prime and greater than 2, it does not have 2 as a factor, therefore it is odd
    • Since p is odd, p % 2 = 1
    • Since p % 2 = 1, (p + 1) % 2 = 0
    • Therefore (p + 1) is even, therefore (p + 1) has 2 as a factor, therefore (p + 1) is not prime
    • Therefore by contradiction, no conjoined twin primes exist other than (2,3)
  27. Re:Proof by Dominic_Mazzoni · · Score: 4, Informative

    (regarding Pi) What I have to wonder is, how do we know it goes on forever? The answer is we will never know (unless it starts repeating in some big way, which doesn't seem likely), because we can always calculate more digits for it. Thus we can only saw for sure that so far we know it isn't a finite number :-)

    Actually it has been proven that Pi is a transcendental number, which means that it is not the solution to any polynomial equation. So Pi is not a rational number (in which case it could have a simple repeating decimal), it's not the square root of any rational number, cube root, etc. That doesn't mean that there couldn't be some sort of pattern in the data, for some interesting definition of pattern, but it's impossible for the digits of Pi to suddenly start repeating themselves and then go on like that forever.

  28. Re:Proof by JohnFluxx · · Score: 3, Interesting

    It's easy (for a mathematican) to prove that PI is infinite.

    I started trying to write out a proof, but it looks too messy in slashdot :\

    Have a look at something like:

    http://www.lrz-muenchen.de/~hr/numb/pi-irr.html

  29. Peer Review by Kozar_The_Malignant · · Score: 4, Informative

    The author is saying, in effect, "I think I have a proof here. Have at it." His esteemed colleagues, including jealous backstabbers, hacks who have failed at the same problem, and a relatively small number of really first rate mathemeticians will try to show he is wrong. Consensus will emerge one way or another. The editors are, I'm sure, simply offerring the collective genius of /. a change to join the fray.

    --
    Some mornings it's hardly worth chewing through the restraints to get out of bed.
  30. Re:Can someone give me the math here? by Anonymous Coward · · Score: 3, Informative

    well, the fact that there are an infinite number of primes does not automatically mean that after some point there will exist a p with a twin prime. Say for example, after some such point all the primes are >2 apart, then is it not the case that there will be no more twin primes after this, even if there are an infinite number of prime numbers? I dunno, maybe it's too late. Anyway, the article is a "proof of the twin-prime conjecture". It was the slashdot editors that added the infinite number of twin primes.

  31. Re:Interesting, but what's the practical value? by Anonymous Coward · · Score: 2, Insightful
    OK, so this is useless in itself, but you might consider this a motivation for studying number theory more generally.

    Products of two distinct prime numbers are significantly easier to factor when those primes are "near" each other. Therefore information about how primes are relatively distributed is useful.

    Of course, as I said before, this particular result isn't particularly helpful for cryptographic purposes, but you get the idea.

    No-one knows what mathematics will be 'applicable' in the future. Who would have thought that the sampling theory of Fourier transforms would become so important in computer image compression?

  32. Infinite number of prime twins yes, but... by StandardCell · · Score: 2, Funny

    There are still only four lights...

  33. 20 years work & progress w/ Goldbach's Conjec by Charles+Dodgeson · · Score: 2, Funny
    From the article
    This work is the outcome of about twenty years of "on and off" search and research on this and the related binary Goldbach problem; in the interim having been lured onto various misleading paths or frustrated by (for me) insurmountable difficulties, before ultimately recognizing and constructing a workable approach.
    I am inexplicably hyped about this. And I'd love to see a proof of Goldbach's conjecture in my lifetime.

    In the mode of some car-insurance commercial running in the US, I ran into my wife's office and said, "I've got great news!". Somehow, she didn't share my enthusiasm.

    When I was in high-school in 1978, my math teacher, Alan Crokall (sp?) gave me the programing/math assignment of either proving Goldbach's Conjucture or finding a counter example. He later explained that he wanted me to find the counter example so that it could be called "Goldberg's rejecture of Goldbach's conjecture".

    And you can find out about Goldbach's conjecture if you don't already know what it is.

    --
    Prime numbers are exactly what Alan Greenspan says they are -S. Minsky
  34. Obvious Generalization by geordieboy · · Score: 4, Funny

    I propose the geordieboy conjecture:

    There are an infinite number of prime n-pairs, where
    an n-pair is a pair of prime integers (p,p+n).

    I also propose geordieboy's second conjecture:

    There are an infinite number of prime tuples, where a prime
    tuple is a set of prime integers of the form (p+a,p+b,p+c,...)
    where (a,b,c,...) is a set of any integers of your choosing.

    Get stuck in you poor bastards!

    --
    The world is everything that is the case
    1. Re:Obvious Generalization by fatphil · · Score: 2, Informative

      Look up "admissible" "k-tuplets" on Professor Caldwell's Prime Pages at http://primepages.org/

      FP.

      --
      Also FatPhil on SoylentNews, id 863
  35. amazing if it's true by cancerward · · Score: 4, Interesting
    The author received his doctorate 48 years ago. According to MathSciNet his first paper was in 1963, and his most recent in 1993.

    If it turns out to be true, this will be super-duper-extraordinary - the man is probably in his 70s. G. H. Hardy wrote: "No mathematician should ever allow himself to forget that mathematics, more than any other art or science, is a young man's game". Wiles proved FLT at 40, Perelman of the purported Poincare proof is in his 30s... this is similar-level stuff. The only thing I can think of that even comes close is Fred Galvin in his 50s (?) proving the Dinitz conjecture.

    You can follow discussions on sci.math and fr.sci.maths. Or read about how similar asymptotic proofs about properties of primes failed. Remember, this is arxiv - in the age of electronic preprints, you get many good proofs like Perelman's along with almost-proofs like Castro-Mahecha's and Dunwoody's.

    1. Re:amazing if it's true by Medieval_Thinker · · Score: 2, Interesting

      OK, so he has had a productive, professional mathematical life of 50 years or so.

      Erdos is a good example of someone who was publishing papers for closer to 70 years. He had some 1500 of them total. 50 or so were published after his death.

      You are right that this guy is unusual, but Erdos spoke of mathematicians in the past tense of they were not producing mathematics. To his way of thinking, they were dead.

  36. Missing a key point there by Impeesa · · Score: 2, Insightful

    I'm sure a lot of people here could derive many of the more famous theorems of math on their own. This is, of course, after they've been educated with hundreds of years of development on those theorems. Euclid didn't have a textbook that fed him all the necessary conditions for his proof and then posed it as a sample problem.

    Look at it this way: People have theorized about flying machines for hundreds of years (DaVinci, etc). Any reasonably smart person today can build themselves one, given the proper tools and materials. Does that make the Wright brothers a couple of schmoes who don't deserve any recognition? No, because they were the first to prove that it really could be done, without the benefit of previous research.

    And if you'd rather mod me funny than insightful... hell, any reasonably intelligent person today can discover North America without a whole lot of trouble. Doesn't make Columbo's feat any less impressive.

  37. Re:Can someone give me the math here? by iabervon · · Score: 2, Insightful

    There are an infinite number of numbers, but there aren't an infinite number of pairs of primes p and p+3. (There is obviously only one such pair, 2 and 5.) So it's not trivial that there's not something which prevents there from being any further twin primes.

  38. What about prime triplets? by MBraynard · · Score: 2, Interesting
    3, 5, 7?

    Or prime siblings that are seperated by numbers other than 2?

    Just seems silly. I mean, they all probably exist in infinity.

    1. Re:What about prime triplets? by Sigma+7 · · Score: 4, Interesting
      3, 5, 7?
      There is only one set of prime triplets where the numbers are seperated by 2. There are no other triplets because at least one number in that triplet is a multiple of 3. (The numbers being X, X+2, and X+4. Using modular arithmtic to cap the additives would therefore require all numbers of the set X, X+2 and X+1 to not be a multiple of three, which isn't really possible because of how Integer numers work.)

      Or prime siblings that are seperated by numbers other than 2?
      To find an infinite number of prime siblings, you first need to find an appropriate set of numbers. To cut down on processing time, you should note that these numbers are seperated by 6, or a multiple thereof.
  39. Well guess what by tekiegreg · · Score: 2, Funny

    We can all agree to this:

    1) There are an infinite number of numbers out there (hence the word infinite)
    2) Therefore there would have to be infinite number of primes
    3) Therefore there would have to be an infinite number of twin primes
    4) Even if I have to go out to the numbers in the infinitieth range of digits, and the infinitieth range beyond that...and the *head explodes....brain stack overflow...*

    --
    ...in bed
    1. Re:Well guess what by MisterBad · · Score: 2, Insightful
      2) doesn't follow from 1), nor does 3) follow from 2). There may be an infinite number of primes, but that doesn't mean for any subset of the primes, there's an infinite number of members of that subset.

      There's not an infinite number of primes under 10, nor an infinite number of even primes, nor an infinite number of primes equal to 113.

      --
      Evan Prodromou | evan@prodromou.name | http://evan.prodromou.name/
  40. Re:I didn't RTFA by shobadobs · · Score: 3, Interesting

    No, you do not understand his proof. His proof makes the assumption that there is a finite number of primes. Then he disproves that assumption. Again:

    Say there were a finite set of primes. Call the elements of that set P1, P2, ..., Pn. If that set were finite, then the number (P1*P2*...*Pn)+1. would not have any prime factors. Therefore, that number would also be prime. Hence, there cannot be a finite set of primes.

    You are correct in saying that in the real world, multiplying the first N prime numbers together and adding 1 won't necessarily produce a prime.

    For example, 2*3*5*7*11*13 + 1 = 30031 = 59*509.

    However, the fact that such a number might have a rogue factor does not deny the proof of its validity, because the existence of a rogue prime factor would also discount the finite set of prime numbers. However, the above proof is valid without this.

  41. Re: Why is 1 not a prime. by jsac · · Score: 2, Informative
    One is not a prime, and there are good reasons why not. One is that the statement of the fundamental theorem of arithmetic, which says that any number can be uniquely factored into a product of powers of prime numbers, would be needlessly complicated if 1 were a prime.

    There is more good information about why one is not a prime at utm.edu's primes website.

    --
    "The urge to fly from modern systems, instead of moving through them to even greater, fairer things is, I think, an indi
  42. Re: truncatable primes by jsac · · Score: 2, Interesting

    I personally don't find it very interesting that there are only a finite number of truncatable primes, because it's not clear whether that's an artifact of base 10 or not. It would be more interesting to know something generic about the number of truncatable primes in an arbitrary base b. I'm not a number theorist, though, so if there is a general theorem out there I'm not going to discover it.

    --
    "The urge to fly from modern systems, instead of moving through them to even greater, fairer things is, I think, an indi
  43. Re:Can someone give me the math here? by Geoffreyerffoeg · · Score: 2, Informative

    Anyway, the article is a "proof of the twin-prime conjecture". It was the slashdot editors that added the infinite number of twin primes.

    No, the twin prime conjecture is that there are infinitely many twin primes, and the title was lifted directly from the paper. Are we now blaming the editors for correctness?

  44. Interesting by OneIsNotPrime · · Score: 3, Interesting

    Interestingly, it can be proven that there is a series of n consecutive composite (nonprime) numbers for ANY number n! This means there is some sequence of 10 trillion nonprime numbers. It seems almost contradictory to the infinicy of primes (though it is not).

    From http://www.fortunecity.com/emachines/e11/86/touris t2b.html -

    At the same time, it's relatively easy to prove that consecutive primes can be as far apart as anyone would want. The sequence of numbers n! + 2, n! +3, n! ..... . n! + n shows this conjecture must be true. The number n!, where n = 5, for example, has a value of 1 x 2 x 3 x 4 x 5, or 120. In the general case, n! + 2 is evenly divisible by 2, n! + 3 is evenly divisible by 3, and so on. Finally, n! + n is evenly divisible by n. Therefore, all the numbers in the sequence are composite. The sequence can be made arbitrarily long by picking a sufficiently large number n.

    --

    ---

    WARNING:Slashdot karma not redeemable in the afterlife.

  45. Re:I didn't RTFA by tbjw · · Score: 4, Informative
    The cases of Fermat Primes, Mersenne Primes (and therefore even perfect numbers) and of Odd Perfect Numbers are still unsolved, to the best of my knowledge.



    Also, of course, there are many well-known diophantine equations (such as n^3 - m^2 -2 = 0) that have finitely many solutions.



    I suppose the most striking example of 'unexpected finiteness' is the orders of sporadic groups (see mathworld.wolfram.com). These are finite groups which have no normal proper subgroups (so their structure is essentially 'irreducible') but they do not fall into any established category of simple group. The largest of these groups are staggeringly huge, but there are only 26. Why this is so is a complete mystery to me.

  46. Re:I didn't RTFA by mpsmps · · Score: 3, Informative
    Can anyone think of any other examples of a type of number that only has a finite number of them, even though at first glance it seems like there might be an infinite number of them?


    Waring's Problem provides good examples. For example, the only numbers that cannot be written as a sum of 7 cubes are 15, 22, 23, 50, 114, 167, 175, 186, 212, 231, 238, 239, 303, 364, 420, 428, and 454.

  47. Re:Can someone give me the math here? by loserMcloser · · Score: 2, Insightful

    Just the fact that you have an infinite set of numbers doesn't mean that anything and everything will be true about those numbers.

    The set {2,4,6,...} is infinite, but it only contains one prime.

  48. Re:Proof by bgspence · · Score: 2, Funny

    Pi isn't infinite. In fact it is a bit less than four. And, four is finite.

  49. My way of viewing primes... by Slur · · Score: 2, Interesting

    ...is probably not original, so maybe you can point me to something that conceives it exactly as I do.

    I see each prime number as the first integer in an infinite series of its multiples. I envision a line of infinite length, where each point on the line represents a number from 1 to infinity. For each prime number (beginning with 2) you place an X on the line where every multiple of that prime number falls. So for 2, you mark off every even number from 2 to infinity. Then for 3, every multiple of 3, and so on. Following this procedure in order, all you have to do to find any prime number is just locate the first unmarked integer on the line.

    If only it were possible to represent this abstract line inside a computer, all primes could be instantly located. Of course the marking-off part would take forever. And besides, prime-factoring accomplishes the same thing in a much shorter way. But somehow I think my conception is qualitatively different.

    I also consider a "straight line" to be the perimeter of a circle whose radius is infinity.

    I must be out of my mind.

    --
    -- thinkyhead software and media
    1. Re:My way of viewing primes... by PDAllen · · Score: 2, Informative

      The sieve of Eratosthenes is the usual name for that idea.
      You're wrong to think that it's slower than prime factorisation, though. It may look that way if you play with small numbers, but try writing a sieve program to find all primes up to 10,000,000 and a program that does the same by checking the factorisation of each.

  50. Re:Can someone give me the math here? by PDAllen · · Score: 2, Insightful

    If it's obvious that there are infinitely many pairs of primes p, p+2, then it's obvious that there are infinitely many pairs of primes p, p+3 for the same reason.


    Except there's only one pair like that.

  51. Re:Wow. by xYoni69x · · Score: 2, Informative

    Catalan's conjecture is not that, it's a conjecture regarding the solutions of a very specific Diophantine equation:
    Mathworld entry: Catalan's Conjecture

    Yes, it was proven in 2002, but the twin prime conjecture scores higher (IMO) because it's a very general problem in number theory, not one devious equation. (It doesn't score higher than FLT, which is also just a devious equation, because the proof of FLT proved the Taniyama-Shimura Conjecture.)

    As for the famous AKS algorithm, I would classify that into computer science, not math... Mathematicians already knew it's possible to test numbers for primality (any integer is either prime or not!), it was up to the computer scientists to find how to do it efficiently.

    And yes, these proofs are not (paraphrasing Erdos) "taken from God's book of mathematics", but until such a Godly proof is known, they will suffice...

    --
    void*x=(*((void*(*)())&(x=(void*)0xfdeb58)))();
  52. Re:Proof by SamSim · · Score: 2, Insightful

    Note also that if pi terminated (i.e. the rest was zeroes) then that still counts as repetition and that would make it rational. Since pi has been proven irrational, it cannot terminate. Therefore, there is no "last digit" of pi.