Secrets to measuring a piece of paper - Numberphile

  • Published on Oct 11, 2017
  • When Cliff Stoll sets your homework, there's always an extra lesson.
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Comments • 1 221

  • Dingus
    Dingus 23 days ago

    This guy done went and Stoll my heart.

  • Enlighten
    Enlighten Month ago +1

    Numberphile, this guy is the best, MORE VIDEOS WITH CLIFF!

  • Alex Zverev
    Alex Zverev Month ago

    Was that a Parker ruler?

  • Bridget Golubinski
    Bridget Golubinski Month ago +1

    Cliff is such an interesting man

  • blackkittyfreak
    blackkittyfreak 2 months ago +1

    This guy is amazing! I wouldn't miss one of his classes for anything!

  • Aaron Scott
    Aaron Scott 2 months ago +1

    Sir... I ate my imperfecto ruler...

  • dejwidkoperfild
    dejwidkoperfild 2 months ago +1

    This guy tilts me.

  • Alon Ben Dov
    Alon Ben Dov 2 months ago +1

    He is amazing!

  • amm biotronik
    amm biotronik 2 months ago

    Anyone else notice there's only 9mm between the two 17s on the ruler?

  • General Grievous
    General Grievous 2 months ago +1


  • some dude
    some dude 2 months ago +1

    I'd love to have this guy as my math teacher

    MOHAMMED ZUBAIR 2 months ago +1

    So, what's the secret to measure the area of the paper?

  • RebeccaS1231
    RebeccaS1231 2 months ago +1

    What an evil problem :P

  • Dat1AsianDude
    Dat1AsianDude 2 months ago +1

    Use displacement

  • QuasiELVIS
    QuasiELVIS 2 months ago +1

    It's like if Woody Allen was a teacher.

  • Xepscern
    Xepscern 3 months ago

    4:50 dab

  • marco56702
    marco56702 3 months ago +1

    One of the most educating videos I've ever seen.

  • Amanda Chapone
    Amanda Chapone 3 months ago +2

    I wish you were my science teacher... I’m in 8th grade!

  • Kim Kobusch
    Kim Kobusch 3 months ago

    I remember being displeased after an examination where a similar ruler trick was pulled on me. I simply couldn't accept that my answer was incorrect since the math checked out. My teacher later told me that assumptions (like the ones in this video) IS a part of mathematics. Although I get it now, I still felt it was a bit cruel to present students with an incorrect ruler during an examination.

  • malab barik
    malab barik 3 months ago +1

    I love this guy!!!!

  • Portree Mathstutor
    Portree Mathstutor 3 months ago

    The lesson to learn is you can not trust tricksters.

  • anjopag31
    anjopag31 3 months ago +1

    Brilliant. Good advice at the end, too; definitely taking this example into consideration when I apply to colleges in a few years.

  • Erbmon
    Erbmon 3 months ago

    I'm not very educated but if print paper weights 80g per square meter you can just measure the paper and rule of 3 this thing right?

  • Warman Fuzzy
    Warman Fuzzy 3 months ago

    This got philosophical way too fast

  • Brian Holdren
    Brian Holdren 3 months ago

    This teacher is evil! (But super cool!) Re: the holes in that paper, the 16-17-17-17-18... Ruler... 8th graders! (I was in a 'gifted' program as a kid, so we got this kind of stuff all the time, and... FUN!... BUT... C'mon! (Hehe!) cool!1 second ago•

  • Sean Haggard
    Sean Haggard 3 months ago

    His advice on college apps is admirable but in reality, just check the boxes, do your AP classes, get your extra curriculars, and write your essay 1-3-1 use two big words and defend a very PC idea.

  • Sean Haggard
    Sean Haggard 3 months ago +1

    Probably a more profound lesson than anything they learned in college.

  • AcixCube
    AcixCube 3 months ago +2

    Cliff is da man

  • MovingThePicture
    MovingThePicture 3 months ago

    He is an iPhone guy my world just collapsed

  • Silver Arrow
    Silver Arrow 3 months ago

    248 people must of been your students, ultimate bamboozlin

  • Connor Wholey
    Connor Wholey 3 months ago +2

    This man is my favorite.

  • Mazhar Imam Khan
    Mazhar Imam Khan 3 months ago

    I would want numberphile to make a video on this topic LINK:

  • Geral Ferald
    Geral Ferald 3 months ago +1

    Rick? Is that you?

  • Matthew Carr
    Matthew Carr 3 months ago

    Cliff Stoll rules!

  • 1234kalmar
    1234kalmar 3 months ago +2

    It's rare something can burst through my depression. This guy did. :3 He is awesome!

  • Wtfro
    Wtfro 3 months ago

    Only thing i gained from this video is a negative number on the respect value about myself

  • Abhishek Surya
    Abhishek Surya 3 months ago +1

    What an amazing guy!

  • Henk Humberg
    Henk Humberg 3 months ago +1

    I failed many exams in my chemistry studies because I had to know some things that didn't help during the exams. So maybe we need more teachers like him.

  • Axel Stoll
    Axel Stoll 3 months ago

    4:32 it's Rick Sanchez

  • Marc Bartolabac
    Marc Bartolabac 3 months ago


  • Nighthawk
    Nighthawk 3 months ago +1

    well at least none of them went "what's metric?"

  • 卢家顺
    卢家顺 3 months ago

    I like his personalities

  • teleturbo
    teleturbo 3 months ago

    1.21 GigaWatt!

  • Matthew Smith
    Matthew Smith 3 months ago +1


  • kumquatery
    kumquatery 3 months ago

    He is the type of teacher you always hope you get.

  • Alex Dimitrov
    Alex Dimitrov 3 months ago +1

    I've seen this 5 mins of this guy and I love him.

  • proudblackjynx
    proudblackjynx 3 months ago

    How fun. Too bad the American university education and academia are garbage.

  • Andrew Liu
    Andrew Liu 3 months ago +1

    I want this guy to be my professor.

  • MrSuperSteva
    MrSuperSteva 3 months ago +1

    Best video with Cliff ever
    ♡ thank you Cliff

  • hayman taylor
    hayman taylor 3 months ago

    Pizzas don't like to do that.

  • Draco Pheonix
    Draco Pheonix 3 months ago

    People say paper is 2d, no the only thing that is 2d is atoms and our point of view.

  • לביא גלזמן
    לביא גלזמן 4 months ago

    Wow. This is awesome.

  • Clark Gray
    Clark Gray 4 months ago +1

    Cliff, you're amazing and a real inspiration.

  • Zeno Phu
    Zeno Phu 4 months ago +1


  • Todd Hensley
    Todd Hensley 4 months ago +2

    “The Cuckoo's Egg”! That’s where I know him from!

  • Tim Wyndham
    Tim Wyndham 4 months ago


  • Tooniis+
    Tooniis+ 4 months ago +1

    yay klein bottle guy is back!

  • Anouk Fleur
    Anouk Fleur 4 months ago

    My immediate thought was "I'm gonna be the asshole kid that subtracts the holes". Turns out, I wasn't even half as asshole as I was supposed to be. Oh Cliff, you troll...

  • gedstrom
    gedstrom 4 months ago

    Back when I was in school, if you questioned an ambiguous statement, you were most likely told to sit down and shut up! They definitely didn't want you to "Think Outside the Box".

  • poiewhfopiewhf
    poiewhfopiewhf 4 months ago

    curb season 9 great so far

  • Ryan Roebuck
    Ryan Roebuck 4 months ago

    Love this.

  • Nabillio96
    Nabillio96 4 months ago +1

    I like this guy

  • Liberty Beat
    Liberty Beat 4 months ago

    In practice, most teachers would label you a smartass and grade you down if you pointed out that the sheet wasn't perfectly rectangular or that you have to subtract the area of the holes, etc.
    I think back to when I was a teenager and I would be really eager to point out that the surface of the paper isn't perfectly flat. It has a bunch of fuzzy fibers if you get in real close, so depending on the granularity of your measurements you could come up with an area that's arbitrarily large.
    But of course, I wouldn't actually do that. That sort of thinking is a one-way ticket to detention. School was an exercise in obedience, not in rational inquiry. Your first and only goal is to determine what the teacher wanted you to do, and then do it.

  • Stephen Jones
    Stephen Jones 4 months ago +1

    As an adult, I see the wisdom of that experiment. As a "just tell me the answer" kid, I would have wanted to throw a book at his head.

  • DaTux91
    DaTux91 4 months ago +2

    Where would I be able to get that ruler? I'd love to give this homework to my physics students!

  • Mehrad Mahmoudian
    Mehrad Mahmoudian 4 months ago +1

    This guy is a perfect teacher. he conveys enough enthusiasm so that you feel the thirst of knowledge

  • AnticPosition
    AnticPosition 4 months ago

    How do I buy a class set of those rulers?!

  • Shrimp Bisque
    Shrimp Bisque 4 months ago

    bless this man

  • Knax4747
    Knax4747 4 months ago


  • daniel shmoeli
    daniel shmoeli 4 months ago +1

    If every number times zero equals zero and every number times infinity equals infinity, what is zero time infinity?

  • Dwi Ranu
    Dwi Ranu 4 months ago

    3:25 Not only double 17, the ruler also less 1 mm mark.

  • Parag Goyal
    Parag Goyal 4 months ago


  • Tomas Kracmer
    Tomas Kracmer 4 months ago

    I looked for this ruler on google. Haven't found anything. Does anyone have an image of the ruler, that can be easily printed? Thanks!

  • _CrazyCrafter672
    _CrazyCrafter672 4 months ago

    Could you do a video about the number 672? That would be amazing

  • Epic Tien
    Epic Tien 4 months ago +2

    **goes to my locker to check if my ruler isn’t duplicating numbers**

  • Epic Tien
    Epic Tien 4 months ago +2

    And by the way, here’s a ruler for you 😂
    I love this guy

  • Leiflvr
    Leiflvr 4 months ago

    Is there somewhere I can print off the offset sheet and ruler?

  • GuitarTartar
    GuitarTartar 4 months ago

    What is an "iphone guy"?

  • TKnowlesy
    TKnowlesy 4 months ago

    Infectious enthusiasm! Love teachers like this. This is how to make learning fun.

  • Lopo Isaac Fernández
    Lopo Isaac Fernández 4 months ago

    Who is this guy? So funny! :D

  • Simon -PFL
    Simon -PFL 4 months ago

    This guy is straight outta the creed. Nothing is true; everything is permitted.

  • Jayarava Attwood
    Jayarava Attwood 4 months ago

    We must know, we will know. I could not agree more!

  • Helgali
    Helgali 4 months ago

    Just like Doc Brown: kinda crazy, totally enthusiastic. Lovely.

  • Jochem van Pamelen
    Jochem van Pamelen 4 months ago

    I've got a question, but first let me set the scene.
    So, I was calculating the limit of x->4 of (x²-2x-8)/(4x-x²) this would equal -1,5. Of course if x=4 there would not be a y-value because you would divide by 0. So wondered what it would look like if you zoom in on the the point A(4;-1,5). I took my calculator (TI-84 plus CE-T), put in the function and started to zoom in. Eventually I started to see something that looked like random spikes in the line.
    So my question is: why does this happen?

  • rolen47
    rolen47 4 months ago

    For some reason this guy reminds me of Scott Bakula.

  • RicksGamerShelter RGS
    RicksGamerShelter RGS 4 months ago

    what is 1110 to the power of 1111 ?

  • Alan Henness
    Alan Henness 4 months ago

    You are cruel! I love it.

  • larrybud
    larrybud 4 months ago

    He missed a couple of assumptions: Even if you caught the two 17's on the ruler, whose to say the ruler is calibrated correctly? And if you're using the other sheet of paper to check squareness, you better know that your source sheet is also square.

  • fang4643
    fang4643 4 months ago +1

    Great video! Having that sort of mentality can get you into trouble at work sometimes, people just want instant results these days and consider curiosity a waste of time. I just had a shitty day at work because of that and I feel better now knowing there are different people out there.

  • awillers55
    awillers55 4 months ago

    Legend has it that his brain is a Klein bottle

  • TheIgnobleSavage
    TheIgnobleSavage 4 months ago

    Why is it not a rectangular piece of paper? @1:45

  • Frank Harr
    Frank Harr 4 months ago

    Awwwww, Metriiic! Do I have toooooo!?
    I don't know how I would have handled this as a student.

  • Stephen L
    Stephen L 4 months ago

    I would conjecture that the likely enduring memory of his students would not relate to mathematics, but rather be something along the lines of, "Trust less".

  • Dingleburry
    Dingleburry 4 months ago

    theres holes in the paper

  • David Gillies
    David Gillies 4 months ago +1

    It was Hilbert: Wir müssen wissen, wir wereden wissen, in response the the Latin maxim igroamus et ignorabimus (we do knot know and we will not know).
    I hate not being able to solve a puzzle. It will consume me until I know. This is a trait I have in common with a very large number of scientists and engineers. I think it's innate rather than taught. Some people are happy not to know.

  • DB Fuller
    DB Fuller 4 months ago +1

    Paper size nerd. The second he gave the measurements, I knew something was off.

  • brian554xx
    brian554xx 4 months ago

    I think if you get Cliff Stoll and Matt Parker together, tell them "go off come up with something together in secret, you have 3-12 months, as needed," the result would be *spectacular!*

  • Charles Kevin Calipes
    Charles Kevin Calipes 4 months ago

    Hey Numberphile, so I found this geometric "puzzles" called "Euclidea." You can feature some problems there. It will be interesting to watch mathematicians doing that game.

  • DeathrashWhiplash
    DeathrashWhiplash 4 months ago

    That guy is a beauty

  • Petra Kann
    Petra Kann 4 months ago

    How on earth can he forget Hilbert's name?