Ramsey Theory Introduction

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  • Опубліковано 2 гру 2024

КОМЕНТАРІ • 74

  • @williamgallop9425
    @williamgallop9425 Рік тому +47

    Mathematician Paul Erdős once said that if aliens landed on Earth and demanded a precise Ramsey number for 5 or they'd destroy the planet, humanity should divert all of its computing resources to figure out the answer. But if they demanded the Ramsey number for 6, humans should prepare for war.

    • @hunterrehm6165
      @hunterrehm6165  Рік тому +6

      What a great quote! This is a great field of research. I haven't studied Ramsey numbers in particular, but I have looked in to Anti-van der Waerden numbers and Schur numbers!

    • @realshimmerstudios
      @realshimmerstudios 7 місяців тому

      @@hunterrehm6165 i don't understand how they don't know the ramsey numbers for 6, can't you just brute force the solution with programming? I mean, with enough computing power, you can surely make an algorithm to check every possiblity for each number.

    • @brendawilliams8062
      @brendawilliams8062 4 місяці тому +1

      Honey, you’d best get ready to hit the bad lands for that one.

  • @philiprabintagapan3870
    @philiprabintagapan3870 2 роки тому +22

    this explanation is simpler than the one i read on the book. thanks dude

  • @legendsplayground7017
    @legendsplayground7017 4 місяці тому +2

    One of my olympiad competition requires this technique to solve the problem, thanks for that, love your content mayn, Jesus bless

  • @Zoppyification
    @Zoppyification 2 роки тому +20

    Very simple and clear explanation, thanks!

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому +3

      Glad you said something! It means a lot!

  • @benjaminrabiego1121
    @benjaminrabiego1121 3 роки тому +6

    Great vid. Thanks for sharing!

  • @DukeNukem713
    @DukeNukem713 11 місяців тому +2

    If I claim R(5,5) = 72 what can be used to prove it wrong?

  • @mikesnelling9272
    @mikesnelling9272 3 роки тому +4

    excellent clear explanation

  • @shivkarj1456
    @shivkarj1456 3 роки тому +5

    Great video!! Nice to see people using the manim engine.

    • @hunterrehm6165
      @hunterrehm6165  3 роки тому +3

      Thanks! Yeah it’s nice and easy to make some really great animations. Have you tried it?

    • @shivkarj1456
      @shivkarj1456 3 роки тому +2

      @@hunterrehm6165 Not really. But its nice to see the community making good of it.

  • @emilymerian42
    @emilymerian42 3 роки тому +5

    So glad I found your videos!!

  • @notuwuzi6948
    @notuwuzi6948 Рік тому +1

    wow, super underated. subscribing time!

    • @hunterrehm6165
      @hunterrehm6165  Рік тому

      Welcome aboard! I just finished my PhD, so I will be making video more now. What would you like to see? More videos like this one?

  • @ofek8280
    @ofek8280 11 місяців тому +1

    beautiful video! just started learning this ,Thank you!

    • @hunterrehm6165
      @hunterrehm6165  10 місяців тому +1

      Thank you! I’ll be coming out with a new video soon I hope

  • @pascals5408
    @pascals5408 2 роки тому +3

    I don't understand how the pidgeon hole principle helps us with the coloring at 3:40

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому +2

      @hisocar I think of the colors as the bins and the edges as the pigeons. This way, by the (generalized) pigeonhole principle, three of the edges must be colored the same. Does that make sense?

    • @madghostek3026
      @madghostek3026 2 роки тому

      The idea is that nobody forces you to pick 3 red and 2 blue, you can try doing 5 red 0 blue, but no matter what, there always will be at least 3 people connecting to first person, that have same color, lets call them A B and C. This allows constructing the white triangle, at which point we are helpless, no matter what you color the triangle, you either create same color edge between first person and 2 from ABC, or if you try to avoid this situation by not giving same color at all... the white triangle becomes what you wanted to avoid, it has only one color!

    • @Anistuffs
      @Anistuffs 2 роки тому +4

      A bit late, but if you're still having trouble, I think I got what Rehm meant.
      So for 1 person knowing or not knowing 5 others, from their POV, they can only have any one of the following possible mutually exclusive options:
      1. Know all 5
      2. Know 4, and not know 1
      3. Know 3, and not know 2
      4. Know 2, and not know 3
      5. Know 1, and not know 4
      6. Not know all 5
      At 3:19, Rehm claims that using Pigeonhole principle, that person knows at least 3 people or not know at least 3 people.
      You can go through all 6 options listed above and see that, in every case, Rehm's claim is true.
      I'm not fully sure how the Pigeonhole principle is used here, but the ultimate claim is correct.

    • @pcmtutorials
      @pcmtutorials 2 роки тому +1

      Use extended form of Pigeonhole principle i.e. [(n-1)/m] +1...... n=5 and m=2 .. Therefore, [(5-1)/2] +1= 3

  • @jaimejdtrechuelo1696
    @jaimejdtrechuelo1696 10 місяців тому +1

    Such a great video

  • @logicmatthewlearning
    @logicmatthewlearning Рік тому +2

    Thank you! Now I understand!

  • @megamac3664
    @megamac3664 6 місяців тому

    Banger video man I love math

  • @brentdassow1040
    @brentdassow1040 3 роки тому +2

    background music is fire🔥10/10 vid

  • @bowser7878
    @bowser7878 Рік тому

    Thanks Hunter. Good video

    • @hunterrehm6165
      @hunterrehm6165  Рік тому

      You bet! Let me know if there is a topic you are interested in seeing. I can try to make something on it.

  • @Anistuffs
    @Anistuffs 2 роки тому +2

    5:50 You forgot to put the link :(

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      I just added the link in the description! It's just the wiki page, but it does a good job summarizing the known values.

  • @clonebin0
    @clonebin0 3 роки тому +3

    Very good video!

  • @Jacquelinekarlsson_
    @Jacquelinekarlsson_ 3 роки тому +5

    This was so good and helpful, thankyou 😄

    • @hunterrehm6165
      @hunterrehm6165  3 роки тому

      Love to hear it! I am currently getting my PhD so video production is slow, but I hope you subscribed!

  • @fatimazahra7648
    @fatimazahra7648 2 роки тому +1

    this is amazing

  • @galcesana8603
    @galcesana8603 Рік тому +3

    thanks!!

    • @hunterrehm6165
      @hunterrehm6165  Рік тому +1

      Glad you enjoyed it! Let me know if there are any other topics you would like to see!

  • @guyst4188
    @guyst4188 Рік тому

    Great video

    • @hunterrehm6165
      @hunterrehm6165  Рік тому

      Thank you so much! Let me know if there is another topic that interests you!

  • @pcmtutorials
    @pcmtutorials 2 роки тому

    Thanks for the simplest presentation.:)

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому +1

      Oh its my pleasure. Are you interested in graph theory?

    • @pcmtutorials
      @pcmtutorials 2 роки тому

      @@hunterrehm6165 I've taught graph theory on my youtube channel already 😊

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      @@pcmtutorials Awesome! I just checked it out! Love it!

  • @maxdemuynck9850
    @maxdemuynck9850 2 роки тому

    awesome video!!

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      Glad to hear you enjoyed it! Are you interested in graph theory like me?

    • @maxdemuynck9850
      @maxdemuynck9850 2 роки тому +1

      it seems very interesting! I don't know much about it just happened to come across your channel because we used it in analysis as part of a proof of Bolzano weierstrauss

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      @@maxdemuynck9850 Wow that is interesting. It has been a bit since I have seen Bolzano-Weierstrass, but I am surprised to here Ramsey theory was in the proof. Would love to hear more!

  • @rajnikantsharma4054
    @rajnikantsharma4054 3 роки тому +2

    Awesome

  • @kelseyyyy4
    @kelseyyyy4 Рік тому +1

    riveting 🧐

  • @zeydbahadir
    @zeydbahadir 2 роки тому +1

    Where is the link below?

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      My bad. I just added the link to the wiki page in the description. There is a table there which summarizes the known values!

  • @stevegao2888
    @stevegao2888 2 роки тому +1

    Please use the regular way to show your text.thx

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      I will do this for future videos probably!

  • @Itay12353
    @Itay12353 3 роки тому +1

    very helpfull

  • @shreyaskrishna6038
    @shreyaskrishna6038 3 роки тому +1

    Why can't everyone not know eachother though? Ie, all blue?

    • @hunterrehm6165
      @hunterrehm6165  3 роки тому +1

      The theorem states that with 6 people in a room, either 3 people know each other, or 3 people do not. So if 3 people do not know each other, then the theorem is satisfied and we should consider the next case. That proof really just shows that there will necessarily be a monochromatic K_3 in every 2-edge-coloring of a K_6.

  • @vedantsridhar8378
    @vedantsridhar8378 3 місяці тому

    Here from Graham's Number

  • @shahidsafeer6115
    @shahidsafeer6115 9 місяців тому

    Thank u sir love and support from Pakistan ❤

  • @johnashton9678
    @johnashton9678 2 роки тому

    Well, I um. I'll try watching again without drink in my brain.

    • @hunterrehm6165
      @hunterrehm6165  2 роки тому

      Haha let me know if you have any questions! Happy to help.