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Mathematicians Use Mossberg 500 Pump-Action Shotgun To Calculate Pi

KentuckyFC (1144503) writes "Imagine the following scenario. The end of civilization has occurred, zombies have taken over the Earth and all access to modern technology has ended. The few survivors suddenly need to know the value of pi and, being a mathematician, they turn to you. What do you do? According to a couple of Canadian mathematicians, the answer is to repeatedly fire a Mossberg 500 pump action shotgun at a square aluminum target about 20 meters away. Then imagine that the square is inscribed with an arc drawn between opposite corners that maps out a quarter circle. If the sides of the square are equal to 1, then the area of the quarter circle is pi/4. Next, count the number of pellet holes that fall inside the area of the quarter circle as well as the total number of holes. The ratio between these is an estimate of the ratio between the area of the quarter circle and the area of a square, or in other words pi/4. So multiplying this number by 4 will give you an estimate of pi. That's a process known as a Monte Carlo approximation and it is complicated by factors such as the distribution of the pellets not being random. But the mathematicians show how to handle these too. The result? According to this method, pi is 3.13, which is just 0.33 per cent off the true value. Handy if you find yourself in a post-apocalyptic world."

40 of 311 comments (clear)

  1. Drop stones in a circle by Anonymous Coward · · Score: 2, Insightful

    Trace a circle on the ground and drop stones at it.

  2. Keep the shells by Anonymous Coward · · Score: 5, Funny

    In a post apocalypse zombie filled world I'd just say "3" and keep the shotgun shells.

    1. Re:Keep the shells by plover · · Score: 3, Funny

      How about killing two birds with one stone? Stand the zombies in a circle, and fire the rounds at them. Count the number of dead zombies. Now you've got an approximation for Pi AND a bunch of dead zombies. Win-win.

      --
      John
  3. um.... by johnholstein · · Score: 5, Insightful

    ":...being a mathematician, they turn to you." You're not much of a mathematician if you don't already know the value of Pi out to several decimal places without the need to expel valuable ammo in an experiment. /john

    1. Re:um.... by Baloroth · · Score: 2

      Relevant SMBC.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
    2. Re:um.... by Dancindan84 · · Score: 2

      It's just a way for mathematicians to get people to stop asking inane questions during the apocalypse.

      "Can you estimate Pi?"
      "Sure. Hand me that shotgun."

      "Do you know Euler's Number offhand?"
      "Of course. Hand me that bazooka."

      "What's Pythagoras' constant?"
      "Seriously? Do you see a tank around here?" Eventually you get left in peace.

      --
      "Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
  4. Only in America... by Max_W · · Score: 5, Insightful

    a gun to calculate Pi value...

    1. Re:Only in America... by Nidi62 · · Score: 3, Funny

      a gun to calculate Pi value...

      According to a couple of Canadian mathematicians,

      I didn't realize we had annexed Canada recently. I hope we didn't also get Quebec.

      --
      The only thing necessary for evil to triumph is for it to be pitted against a slightly greater evil
    2. Re:Only in America... by cold+fjord · · Score: 4, Funny

      Don't be silly, the method should work in any country.

      --
      much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
    3. Re:Only in America... by Baloroth · · Score: 2, Interesting

      I hate to break it to you, but the ancient term "America" refers to the whole continent, Canada included.

      Nope - that would be "North America."

      Hey, if you're going to be a pedant...

      Ok, since we're being pedantic: technically, "America" refers to the entire landmass (made up of the continents of North and South America and associated islands). Still includes Canada, though.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
  5. Ask an old person? by gb7djk · · Score: 4, Insightful

    The engineers answer: ask someone who went to school before the zombies arrived. Mind you, an engineer probably wouldn't have to bother. Rhetorical question: I wonder how Euclid managed?

    1. Re:Ask an old person? by Roxoff · · Score: 4, Funny

      Euclid's Shotgun? Is that much like Occam's Razor, or Shrodinger's Cat?

      --
      "Is the Chief Priest an Offlian? Do dragons explode in the wood?"
    2. Re:Ask an old person? by Kjella · · Score: 2

      Rhetorical question: I wonder how Euclid managed?

      I know what rhetorical means but really, there's so many obvious ways. Take a piece of string, tie down one end and draw a circle in the sand with the other. Now use the same piece of string to measure out the circle. You'll get an approximation of pi more than good enough for any practical purpose, the only thing "special" about it is that numbers that aren't fractions like pi, e and the square root of 2 was fucking with their understanding of math. Even the ancient druids of Stonehenge could map out a circle, long before Euclid.

      --
      Live today, because you never know what tomorrow brings
  6. Re:I think I just found a title for my thesis by i.r.id10t · · Score: 3, Funny

    Indeed, if a Ma Deuce doesn't solve the problem either the problem is unsolvable or you just need more ammo.

    --
    Don't blame me, I voted for Kodos
  7. Sweet by TerenceJ.Lindsey · · Score: 2

    Alright boys, we used up all our limited ammo but at least we know pi before we die!

  8. Archimedes by Anonymous Coward · · Score: 2, Insightful

    neither had nor needed a shotgun to calculate pi to 2 significant digits, which I'd wager is significantly closer than you're likely to get...

  9. Huh. Who knew... by TheRealSteveDallas · · Score: 2

    We have only been using shotguns for fractions.

  10. I don't understand by MrKaos · · Score: 3, Funny

    Do you put the zombies in front of the square alluminum plate?

    --
    My ism, it's full of beliefs.
  11. Why calculate pi? by Anonymous Coward · · Score: 2

    In a post-apocalyptic world, why not fix the mistake and calculate the correct constant, tau?

  12. 2 tips for preppers by CQDX · · Score: 4, Insightful

    First, pack at least couple solar powered calculators. You can get cheap scientific calculators at the dollar store. They'll be worth their weight in gold during the second Renaissance. Second, don't give the mathematician any weapons. Let him be a mule, carrying any tech books you find along the way. Give him a pencil and pad of paper and let him re-derive the whole of known mathematics.

  13. So wait, shotguns are more accurate than the bible by netsavior · · Score: 5, Interesting

    "And he made a molten sea, ten cubits from the one rim to the other it was round all about, and...a line of thirty cubits did compass it round about....And it was an hand breadth thick...." — First Kings, chapter 7, verses 23 and 26

    30/10 = 3

    Bible Pi = 95.493% accurate
    Shotgun Pi = 99.67% accurate

  14. Re:Um, no? by Dancindan84 · · Score: 5, Interesting

    This reminded me of a story my wife told thinking it made her math teacher sound smart. She said that they sat down and figured out that it was most efficient to mow their lawn in a series of circles rather than in a rectangle or lines like most people do. I facepalmed and she asked me why.

    I responded with something along the lines of, "I'm sure they figured out that mowing in circles is theoretically more efficient, except that most lawn mowers have a finite turn radius that makes it impractical and push mowers can't cut while turning since they have to be lifted."

    "Also, people tend to get dizzy going in circles for more than a few seconds, so unless they employ a ballerina to do their lawn mowing, all they showed it why you don't ask a mathematician to solve an engineering problem."

    --
    "Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
  15. Re:Um, no? by LordLimecat · · Score: 3, Insightful

    Im not clear how it could be "more efficient". Your average speed will be higher on the straight-aways, and no matter what shape you do you will have to mow the entire area of your lawn. How you fill it in doesnt change the amount needing to be done.

  16. Re:fixing the parent posting by mlts · · Score: 5, Interesting

    I'm wondering if they got results without a choke, or at full choke. This might be statistically significant.

  17. Re:Um, no? by JaredOfEuropa · · Score: 4, Funny

    Just keep firing, soldier! Accuracy will improve.

    And that is of course the reason these guys used this particular method to estimate pi: not "science", but as an excuse to blast away with a shotgun. As if you need an excuse for that...

    --
    If construction was anything like programming, an incorrectly fitted lock would bring down the entire building...
  18. Re:So wait, shotguns are more accurate than the bi by garyebickford · · Score: 3, Interesting

    Research back in the 1930s discovered that there's more to that verse than appears. In Hebrew, the letters are also numbers, and the number values of letters and words are often very significant to the reading. There is a 'jot' ('jot' and 'tittle' are like diacritic marks) in the original, which here means, "look deeper". So with a bit of deeper analysis, one finds that the letters there turn out to make up a fraction. I forget what the fraction is, but it's something like 31/222 or some such, and with the fraction the value is within 1% or less of pi. This is discussed in one of Chuck Missler's research texts, about that book in the Bible.

    --
    It's easier to be a result of the past, but more fun to be a cause of the future! http://www.spacefinancegroup.com/
  19. Re:Um, no? by noh8rz10 · · Score: 2

    or maybe your wife is tired of you talking to her like she's a child.

  20. a bunch of dead zombies by dtmos · · Score: 2

    AND a bunch of dead zombies.

    What's a dead zombie? Is this some kind of recursion?

    (Getting old has a lot of advantages, but one of the disadvantages is that it's harder to keep track of popular memes. I mean, I never understood the whole "vampire" thing, and now we're on to zombies. What's next?)

  21. Buffon's needle by BlackPignouf · · Score: 2
  22. Nothing special. by 140Mandak262Jamuna · · Score: 3, Insightful

    This was one for the first exercises done in Introduction to Computing 201, using a random number generator to find the value of PI. I did it in FORTRAN back in the days with punch cards in IBM370/155. Recently I did it again to teach myself MPI. This is a basic exercise in Probability and Statistics course. Once can draw a circle in fly paper. The number of bugs caught inside the circle to total number of bugs caught would be approximately PI/4. But that would get you a better headline, "Bugs commit suicide to tell us the value of PI".

    --
    sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
  23. Re:So wait, shotguns are more accurate than the bi by Anonymous Coward · · Score: 5, Insightful

    That's a lot of numerological bullshit. The truth is much simpler. The Bible says it's 10 cubits across and 30 cubits around. The diameter is provided with one significant figure, and the circumference is also provided with one significant figure. Dividing the two gives you pi... to one significant figure. Anyone who says "this proves that the Biblical authors thought pi = 3.00 [3 significant figures]" must not have done very well in physics class.

  24. Re:Zombie make it news? by JustOK · · Score: 2

    In the post-apocalypse world, you have to include "...NOT on the internet" to get a new patent.

    --
    rewriting history since 2109
  25. Re:fixing the parent posting by Jeremiah+Cornelius · · Score: 5, Funny

    They would only need confidence in the random distribution of holes in the target.

    Goddamn mathematician wasting precious ammunition to have a statistics wank-fest after MY goddamn zombie apocalypse?

    I'd put a random distribution of holes in his worthless head!

    --
    "Flyin' in just a sweet place,
    Never been known to fail..."
  26. Infinite series by Deadstick · · Score: 2

    Just calculate 4-4/3+4/5-4/7+4/9-4/11... to as many significant figures as you'd like. It converges to exactly pi.

  27. Time saving tip for these guys by Trailer+Trash · · Score: 4, Funny

    Come to Tennessee or Indiana and drive out in the country. Pretty much half the stop signs have already been prepped for you - you just have to count holes.

  28. Re:fixing the parent posting by K.+S.+Kyosuke · · Score: 5, Funny

    Probably without. First, choking deprives your brain of oxygen, making such intellectual efforts as calculating the value of pi much more difficult. Second, any attempt at choking a shotgun-armed mathematician is not just unlikely to be successful but an outright bad idea in general.

    --
    Ezekiel 23:20
  29. Re:Um, no? by jeremyp · · Score: 3, Insightful

    And you waste a load of shotgun shells that are going to be extremely valuable in the post apocalypse.

    --
    All I want is a secure system where it's easy to do anything I want. Is that too much to ask ~~ Randall Munroe
  30. Re:fixing the parent posting by drinkypoo · · Score: 2

    I'd put a random distribution of holes in his worthless head!

    I believe you mean psuedorandom. (*bang*)

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  31. Or find a library? by RevWaldo · · Score: 2

    There are definitely old school reference books with the value of pi to hundreds if not thousands of decimal places.

    Unless the zombies take up reading or eat books, and you don't break your glasses, we're good to go.

    .

  32. Re:fixing the parent posting by Talderas · · Score: 2

    You are the best kind of correct.

    Technically correct.

    --
    "Lack of speed can be overcome. In the worst case by patience." --Znork