Which Ancient Questions About Prime Numbers Can We Answer?

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  • Опубліковано 26 гру 2024
  • In this class, we’ll perform a bunch of surprisingly simple proofs from history related to prime numbers and infinity, leading up to modern questions about prime numbers that mathematicians are still working on cracking.
    To note: in this episode, when I talk about "prime factorizations" of “all/any numbers”, I'm referring to “whole numbers greater than 1” in specific, since 1 is considered neither prime nor composite.
    Stay tuned for more crazy learning!
    ----------------------
    Combo Class, taught by Domotro, is an unconventional learning experience where anybody (whether they're a fan of normal school or not) can become excited to learn rare things about math, science, language, and more. Also check out the shorter videos on the Combo Class Shorts channel (and TikTok page). Thanks for coming to Combo Class!
    DISCLAIMER: The burning clock in the intro (and any other uses of fire, tools, or science experiments in this series) was done in a professional and safe way. Don't try to copy anything you see in this series yourself.

КОМЕНТАРІ • 123

  • @anieldayyanelday1771
    @anieldayyanelday1771 2 роки тому +133

    I think "arbitrary largeness" works better than saying "infinite gap". Infinite gap seems to suggest that the next prime is infinitely far away (which never arrives)

    • @RiotGearEpsilon
      @RiotGearEpsilon 2 роки тому +4

      "Illimitable bigness"

    • @JamesSpeiser
      @JamesSpeiser Рік тому +8

      extra bigly

    • @kierhudson1328
      @kierhudson1328 Рік тому +1

      finite gap then?

    • @tissuepaper9962
      @tissuepaper9962 Рік тому +1

      If the size of the gaps grows at a faster rate than the totient function ( φ(x) = card({a | a ≤ x and a ∈ P}) ), then I think "infinite gap" is legitimate.

    • @BaseSixBasics
      @BaseSixBasics Рік тому +1

      But there are an infinite number of gaps beforehand, so it can be true and there can still be an infinite number of primes! This is what WHEEEL ALGEBRA is about

  • @janberentsen9890
    @janberentsen9890 7 місяців тому +6

    The (p + 1)(p - 1) reveal just is incredibly well executed. You had me physically sitting on the edge of my chair, to serve me one of the most satisfying possible eureka moments. Brilliant!

  • @Lugmillord
    @Lugmillord 2 роки тому +70

    That large gap using factorials was really cool and surprisingly simple

  • @apollo314pc
    @apollo314pc 2 роки тому +33

    Your enthusiasm for Maths just rocks. I will be endeavouring to watch all your videos ....thanks so much

  • @TessHKM
    @TessHKM 2 роки тому +42

    I would love to see a video covering math in the more "geometric" way that pre-algebraic mathematicians understood it.

  • @briangronberg6507
    @briangronberg6507 Рік тому +3

    I love Euclid’s proof that there are infinitely many primes. And when I realized 2 wasn’t (always) prime (it’s not a Gaussian prime) my whole conception of math started to pivot.

  • @tomkerruish2982
    @tomkerruish2982 7 місяців тому +2

    0:41 Considering the opening line of 1984, perhaps it's good that 13 isn't on clocks.

  • @Alexander_Grant
    @Alexander_Grant 2 роки тому +8

    You remind me so much of one of my astronomy professors back in my college days when I was studying physics a few years ago. It was my first semester, my entire school life up to that point had been in the rural South, and he was from Britain, but that guy came to lecture with the same enthusiasm you show every time I saw him. It was awesome, and the first time I really saw someone teaching with that level of enthusiasm.

  • @JamesSpeiser
    @JamesSpeiser Рік тому +2

    10:26 gave me a quick glimpse into the reality that primes are infinite in a way I never saw before.

  • @GayAnnabeth
    @GayAnnabeth 2 роки тому +16

    I like how the 24 rule only work for every prime >= 5
    but when you try looking at 2 and 3, you get 3 and 8, which multiply to make 24

    • @romano-britishmedli7407
      @romano-britishmedli7407 2 роки тому +6

      Yeah, it's still a nice way tying 2²-1 and 3²-1 to 24, which is very neat and satisfies my completionary urge.

    • @GayAnnabeth
      @GayAnnabeth 2 роки тому +3

      @@romano-britishmedli7407 it is nice indeed

  • @GayAnnabeth
    @GayAnnabeth 2 роки тому +137

    by my personal gut feeling, there probably SHOULD be infinite twin primes. but my gut feelings are hardly a proof, but I'm just pointing out how it would be more surprising if there were finite pairs of twin primes

    • @navjotsingh2251
      @navjotsingh2251 2 роки тому +1

      Some proofs start off by suspicions or gut feelings about a particular structure or problem. Get your pen and paper and start investigating! Mathematics is a science, feel free to experiment and see where it gets you.
      It’s one thing I love about math, you are free to experiment and test your thoughts.

    • @aogasd
      @aogasd 2 роки тому +52

      Math paper: there ARE infinitely many twin primes
      Source: trust me bro

    • @Shyguy5104
      @Shyguy5104 2 роки тому +12

      @dsagoa that'sa conjecture, baby!

    • @andreasobama9487
      @andreasobama9487 2 роки тому +22

      @@aogasd fermats theorem be like

    • @ZeroRelevance
      @ZeroRelevance 2 роки тому +16

      @@aogasd Proof by intuition

  • @EnderMega
    @EnderMega 2 роки тому +4

    I just found this guy and already love him! He is always smilling and is happy to teach the stuff he likes!!! Keep it up bro :D

  • @daniell7413
    @daniell7413 2 роки тому +19

    Love the enthusiasm, keep it up!

  • @Misteribel
    @Misteribel 2 роки тому +8

    Assuming the Elliott-Halberstam conjecture, there exist infinitely many primes with a gap of at least 6. This was shown in the same Polymath project. Without the conjecture (which isn’t proven yet), the gap is at least 246 as shown here. Terence Tao has been instrumental in pushing this forward.

  • @publiconions6313
    @publiconions6313 2 роки тому +6

    That was one of the best infinite primes proofs explanations I've seen... love this guy!!.. instant subscribe. Brady Haran - get this guy on your show before he overtakes! : )

    • @ComboClass
      @ComboClass  2 роки тому +4

      I would love to present something on Numberphile with Brady someday :)

    • @Brunoenribeiro
      @Brunoenribeiro 2 роки тому +1

      that needs to happen! Let's storm the numberphile comment section haha

    • @martysears
      @martysears Рік тому

      I'm sure they would love to have you on

    • @tomkerruish2982
      @tomkerruish2982 7 місяців тому

      ​​@ComboClass Don't you live in the same town as the Klein Bottle guy? He seems pretty approachable.

  • @aknightofislamicarabia5543
    @aknightofislamicarabia5543 Рік тому

    Top-tier channel. Glad to be here before the algorithm catches on and boosts you to a mill.

  • @brandonthesteele
    @brandonthesteele Рік тому

    You're fascinated by the same things I'm fascinated by! Keep this up, I've been eating these classes up for the past couple months.

  • @pvanukoff
    @pvanukoff 2 роки тому +1

    I love this dude's energy.

  • @AA-gl1dr
    @AA-gl1dr 2 роки тому +12

    I like the content. Don’t understand the clocks but it’s a vibe. Nice videos. Subbed!

    • @ComboClass
      @ComboClass  2 роки тому +8

      Gonna explain the clocks in a video next month haha

  • @kalebmaciver7117
    @kalebmaciver7117 2 роки тому +1

    I really appreciate the way you portray the information; it is incredibly engaging.

  • @Pause0
    @Pause0 Рік тому

    This episode really put into context for me what infinite numbers really means, cause its easy to just say numbers are infinite because n+1 always works but that doesn't really make you realize what the scope of numbers and math really is, but realizing that not only are primes infinite but that their gap can be arbitrarily large really put it in perspective, the fact that one infinite set of numbers can be spaced so far apart within another infinite set of numbers just kind of boggles my mind.

  • @christianstonecipher1547
    @christianstonecipher1547 2 роки тому +5

    That is certainly a more concise way of proving the p^2-1 is a multiple of 24 than what I learned.
    The way I learned it you considered the primes modulo 6. So 0,2,4 mod 6 are obviously composite (ignoring 2) so there are no primes other than 2 that are 0,2,4 mod 6. Similarly 3 mod 6 has to be a multiple of 3 and thus only 3 is a prime in the case of 3 mod 6. Thus you only needed to consider 1 mod 6 and 5 mod 6 or in other word numbers in the form of 6n+1 and 6n+5 where n is a natural number. So for the 1 mod 6 case p^2-1 = (6n+1)(6n+1)-1 = 36n^2+12n+1-1 = 36n^2+12n which when you take mod 24 you get 12n^2+12n which when n is even you get that 12n^2 = 0 and 12n = 0 mod 12 and when n is odd you get that 12n^2 = 12 and 12n = 12 mod 24 which both result in 12n^2+12n = 0 mod 24 meaning that for all numbers that are 1 mod 6 n^2-1 is a multiple of 24. Similarly for the 5 mod 6 case p^2-1 expands to (6n+5)(6n+5)-1 = 36n^2+60n+25-1 = 36n^2+60n+24 which when taken mod 24 results in 12n^2+12n which we have proven above is a multiple of 24 for all integers. Thus we have proven that for all numbers n where n mod 6 is 1 or 5 then n^2-1 is a multiple of 24 and thus all primes p that are not 2 or 3 satisfy the condition that p^2-1 is a multiple of 24.

  • @Cjendjsidj
    @Cjendjsidj 2 роки тому

    I love how enthusiastic you are😊

  • @carterthaxton
    @carterthaxton Рік тому +1

    Did we ever move on from math to “other units”? I love the math topics you present, btw, and I’m sure I’d love other subjects, too. But I’m definitely here for the math!

    • @ComboClass
      @ComboClass  Рік тому

      This grade ended up more math-heavy than anticipated, but I did mix in a few other topics (language, plants, bubbles, calendars, etc.) although just for 1-2 episodes each. There will definitely be other topics (and probably whole units) in the future, although I've been having a lot of fun with the math and it will probably be the most frequent topic in Grade -2 also

  • @luisg.ontoriaalvarez2334
    @luisg.ontoriaalvarez2334 4 місяці тому

    Thank you for sharing your passion!

  • @tuskiomisham
    @tuskiomisham 2 роки тому

    dude this channel is going places.

  • @kajacx
    @kajacx 2 роки тому +1

    You should do something on the axiom of choice. It leads to some really bizarre theorems and proofs.

    • @tomkerruish2982
      @tomkerruish2982 7 місяців тому

      Q: What's an anagram of Banach-Tarski?
      A: Banach-Tarski Banach-Tarski.

  • @takeguess
    @takeguess 2 роки тому

    Dude you are killing it! Nice Work your videos are super powerful. Excited to watch the channel grow, and see other people stoked on patterns in math.....

  • @steelegagnon5273
    @steelegagnon5273 2 роки тому +1

    i literally love this guy

  • @samuelbailey688
    @samuelbailey688 2 роки тому +1

    I love your videos, they're really fun and talk about stuff I NEVER hear about in math. I'm in Linear Algebra right now and most of this stuff has never been mentioned. Did you have a formal math education or did you just find this stuff yourself?

  • @danielvickery1233
    @danielvickery1233 Місяць тому

    From what you've said, that means for every twin prime pairing, the number between them MUST be divisible by 3.

  • @Gunbudder
    @Gunbudder 2 роки тому

    the prime fact that still melts my brain and i don't want to believe is that for any finite integer, you can find a gap between two primes of that size. that means you can pick ANY arbitrarily large number, even Graham's number, and then if you start listing all positive integers, eventually you will find a prime, and then Graham's number of non-primes, and then another prime. Basically the only way this makes any amount of sense is because there are infinitely many integers and infinitely many primes in that realm. If you have infinite time to count, you can find a chain of non-primes of any finite length because the length is finite. There is no "last prime" though, so the chain has to be finite. but it can be Graham's number!!! that shouldn't be possible! The location of that chain may be as far out as inverse log* of graham's number, but its there. And its practically impossible to find! there is no conceivable way that any sentient species could count fast enough to find it. you would essentially have to be God to know where that chain is in the integers. Or rather, if you found the chain, it could only be the result of god-like powers.

  • @TeaTime0300
    @TeaTime0300 Рік тому

    Fun fact: The arbitrary largeness of the gap is equal to n-2 (where n is the factorial number)

  • @kasugaryuichi9767
    @kasugaryuichi9767 2 роки тому

    Lovely presentation!

  • @JamesonNichols
    @JamesonNichols Рік тому

    I just started watching your channel. Every episode has left me saying what the fuck.
    I subbed.

  • @josephd6115
    @josephd6115 2 роки тому +2

    This channel is so criminally underrated

  • @mati.benapezo
    @mati.benapezo 2 роки тому

    Once I imagined something somewhat like the primorial, and now I know it exist. Also you can think of the biggest primorial as the most antiprime (or prime composed) number, I guess.

  • @ehmaree
    @ehmaree 2 роки тому

    I think I have a proof for twin primes. Take P# where P is a large prime number. P# + 1 must be prime, for reasons explained in the video (around the 5:00 mark, I think.) P# - 1 must also be prime for the same reasons. (P# + 1) - (P# - 1) = 2. Twin primes are infinite.

    • @ehmaree
      @ehmaree 2 роки тому

      Is it really that easy?

    • @AstroEli133
      @AstroEli133 2 роки тому +3

      @@ehmaree No, someone already posted a comment about this and someone else corrected them. The proof doesn't work because there is no biggest prime number, so P doesn't exist. :)

    • @ehmaree
      @ehmaree 2 роки тому

      @@AstroEli133 Yeah, I kind of realized that around yesterday. Oh well

  • @Niohimself
    @Niohimself 2 роки тому +2

    Random ponder: is it a problem for mathematicians that, when you talk about infinite things, it's sometimes ambiguous if you mean "THE infinity" vs "something else that also has the property of being infinite"?

  • @rothgang
    @rothgang 2 роки тому

    I think that if you can prove whether or not there is a lower bounding number for the distance between infinite amounts of prime pairs, then you can prove whether that bound is 2. If the proven bound keeps shrinking, then there really isn't any reason to believe that the ultimate bounding number isn't 2.

  • @jerryiuliano871
    @jerryiuliano871 7 місяців тому

    (.75*(x^2))+(1.5*x)+23 =
    mostly Eisenstein primes or semi-primes, when x is an even number.

  • @NikaTark
    @NikaTark 2 роки тому +1

    Doesn't infinite prime proof, one at 5:00, also prove that there are infinitely many twin primes?
    since P#-1 and P#+1 are both primes and one is 2 more than the other making them twin primes?

    • @Bovineprogrammer
      @Bovineprogrammer 2 роки тому +2

      P#-1 and P#+1 are not necessarily prime - they can be composite numbers with prime factors larger than P. The proof works by assuming you have all primes and then constructing a number which is divisible by a prime you don't have.

  • @bennekin
    @bennekin 3 місяці тому

    hey I’m loving your videos so far but I really feel the need to say you look like Dream if he was in ratatouille

  • @adamyong2151
    @adamyong2151 2 роки тому

    Can you teach me, how to determine whether the number is a prime or not by using the fastest method??

  • @maht0x
    @maht0x 4 місяці тому

    a lesson from the time before the birth of threeven - so now the videos can be classified BT and AT and the span from here in BT to a known (to me) AT is a year. I have a side quest to find it (I hope it is not later in this episode now I wrote all that at 10:00)

  • @shortguy436
    @shortguy436 2 роки тому +2

    I have to point out that the thumbnail for this video looks like a rap music video

  • @shadow357
    @shadow357 2 роки тому

    I love your videos

  • @stefanfincken4359
    @stefanfincken4359 Рік тому

    With the mod vid explaining base 10 and the speciality of whatever the mod is minus 1, so 0 for mod 10... This prime multiple of 24 + 1 bit has me questioning what happens when you use a mods with prime numbers as the base...?!
    Anyway.. Jus tfound you today. and I stank at maths and hated it in school. But do find it very interesting. Been watching numberphile for years and mostly understand very little of it.. But love the way you break things down., So will def be watching more.

    • @ComboClass
      @ComboClass  Рік тому +1

      Thanks! To see about some benefits of prime mods, check out my new-ish one about modular division :)

    • @stefanfincken4359
      @stefanfincken4359 Рік тому

      @@ComboClass
      I'm working my way up. I'm at the apple break vid rn. :)

  • @boptautology4691
    @boptautology4691 3 місяці тому

    the supernaturals have infinitely large gaps in between infinitely large primes.

  • @kevinderoo3880
    @kevinderoo3880 2 роки тому

    1:00 I can tell grammar isn't his *prime* subject (pun intended)

  • @michaelhaack7216
    @michaelhaack7216 2 роки тому +2

    Humor me... can you show this sequence evaluation with an 11 integer/12 integer sequence!? Prime interests lol

    • @ComboClass
      @ComboClass  2 роки тому

      Not sure what you mean exactly. If you explain that more, I might be able to help

  • @apusapus71
    @apusapus71 Рік тому

    Are prime numbers the only sequence where the nth term is unpredictable?

  • @desfurria6232
    @desfurria6232 2 роки тому

    Can Prime be The number itself? Like nothing bigger than Prime itself, and all other things are expressions of it.

  • @TheNameOfJesus
    @TheNameOfJesus 2 роки тому

    The Fundamental Theorem of Arithmetic should have been called the Fundamental Arithmetic Theorem. For the acronym.

  • @pingnick
    @pingnick 2 роки тому +1

    Nice Tiktoks too wow thanks♾♾♾♾♾☮️💟😘🥰😍😻🤩🤯🗽🌈

    • @ComboClass
      @ComboClass  2 роки тому +2

      Thanks I appreciate it!

    • @pingnick
      @pingnick 2 роки тому

      @@ComboClass 🎬♾🤯

  • @SatisfyingWhirlpools
    @SatisfyingWhirlpools Рік тому

    "We could make every number" except 1 >: )

  • @steelegagnon5273
    @steelegagnon5273 2 роки тому

    PLEASE TALK ABOUT THE REIMOND HYPOTHESES SOMETIME

  • @pukaman2000
    @pukaman2000 7 місяців тому

    Fun.

  • @skyjumper4097
    @skyjumper4097 Місяць тому

    70milliom

  • @Maths_Physics_Mathematics
    @Maths_Physics_Mathematics 8 місяців тому +1

    Hi

  • @peterpike
    @peterpike 2 роки тому

    I suspect the twin prime conjecture may have some correlation to the arbitrarily large gaps by n! due to the fact that, while you only showed the numbers that get blocked by ADDING, it actually blocks them by subtracting too. So, n! blocks primes from existing from (n! - n) all the way to (n! + n), with the only exceptions being n! +/- 1, which, if both end up being prime, would automatically be a twin prime. Of course, it's clearly not that simple to PROVE or that would have already been proven. But I suspect if there is an "easy" solution to it, it'll be found in some sort of connection to that fact.
    Also, just for fun, if you could push n to infinity (say by using limits in Calculus) then n! would have every single possible number as a factor. This means that n + 1 would necessarily have no factors at all, except for 1 itself. And the only number that has just 1 as a factor is 1 itself. Thus, implying that n! = 0 when n hits the limit at infinity.

    • @lock_ray
      @lock_ray 2 роки тому

      Regarding lim n! = 0 I suggest reading about p-adic numbers ;)

    • @dabs4270
      @dabs4270 2 роки тому

      You're assuming n! and n! + 1 approach real numbers as n goes to infinity but they dont, so you cant apply real number logic to deduce n! + 1 = 1
      The limit of n! as n goes to infinity is still infinity (assuming you're using the real numbers)

  • @CoughSyrup
    @CoughSyrup 2 роки тому +1

    Wow, look at that lab-coat.
    So white, fresh and unscorched. 💀

  • @angusmacdonald4860
    @angusmacdonald4860 Рік тому

    10x9x8=6×5×4×3×2×1

  • @hoagie911
    @hoagie911 2 роки тому

    You are insane, and I'm okay with that

  • @CatholicSatan
    @CatholicSatan 2 роки тому

    Does not the Fundamental Theorem of Arithmetic (FTA) _assume_ numbers/integers (and hence prime numbers) are infinite? In which case, using FTA to prove there are an infinite number of primes is a circular argument.

    • @dfs-comedy
      @dfs-comedy 2 роки тому +2

      But there are an infinite number of integers. If n is an integer, then so is (n+1). That's by definition... you have to start with some axioms. Give me any integer and I'll give you back one that is bigger... therefore there are an infinite number of integers.

  • @orsonzedd
    @orsonzedd 2 роки тому

    0 isn't prime because it's even. Sorted.

  • @jhomenchak
    @jhomenchak 2 роки тому

    4% of numbers, at most, are prime.

    • @timer1238
      @timer1238 2 роки тому +1

      The actual value is (1-0.999...)% because if you will go further, they are less and less common

    • @memeteam2016
      @memeteam2016 Рік тому

      @@timer1238 The actual value is 0%? lol

  • @pukaman2000
    @pukaman2000 7 місяців тому

    Here is an ethical question for you. Would you hand a 3 year old child a loaded shotgun? If we develop the math correctly (people have been getting close) and accept that math's paradigm shift (hell, the US cannot even get the metric system imposed... but hey, the world thinks that E-MCC was discovered by Einstein and Trump won the 2020 election.). then we will be able to make things that make the atomic bomb look like a birthday candle. Do we really want the people we elect to have such things?

  • @totally_not_a_bot
    @totally_not_a_bot 2 роки тому

    As an example of the infinite primes proof:
    4! = 24
    24 + 1 = 25 = 5*5
    5 is not a factor of 4!
    24 - 1 = 23 which is prime.
    With primordial:
    5# = 2 * 3 * 5 = 30
    30 + 1 = 31 > 5 and is prime.
    QED

  • @Mik1604
    @Mik1604 2 роки тому

    Um. Pz# has no factors, since Pz is prime.

  • @j100j
    @j100j 7 місяців тому +1

    Not unhinged. Unwatchable.