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Math Idle

Mathematicians Use Mossberg 500 Pump-Action Shotgun To Calculate Pi 311

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."
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Mathematicians Use Mossberg 500 Pump-Action Shotgun To Calculate Pi

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  • by Anonymous Coward on Monday April 14, 2014 @09:36AM (#46746543)

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

  • um.... (Score:5, Insightful)

    by johnholstein ( 1735990 ) on Monday April 14, 2014 @09:40AM (#46746583)
    ":...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
  • Only in America... (Score:5, Insightful)

    by Max_W ( 812974 ) on Monday April 14, 2014 @09:40AM (#46746587)
    a gun to calculate Pi value...
  • Ask an old person? (Score:5, Insightful)

    by gb7djk ( 857694 ) * on Monday April 14, 2014 @09:41AM (#46746593) Homepage
    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?
  • Archimedes (Score:2, Insightful)

    by Anonymous Coward on Monday April 14, 2014 @09:46AM (#46746669)

    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...

  • by Anonymous Coward on Monday April 14, 2014 @09:53AM (#46746733)

    Technically speaking Canada is a seperate nation on the continent America. So you can't actually claim for sure that it's misstated, just because USA is often considered the same as America.

  • by CQDX ( 2720013 ) on Monday April 14, 2014 @09:57AM (#46746785)
    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.
  • Re:Um, no? (Score:4, Insightful)

    by LordLimecat ( 1103839 ) on Monday April 14, 2014 @10:09AM (#46746943)

    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.

  • Nothing special. (Score:4, Insightful)

    by 140Mandak262Jamuna ( 970587 ) on Monday April 14, 2014 @10:32AM (#46747223) Journal
    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".
  • by Anonymous Coward on Monday April 14, 2014 @10:35AM (#46747259)

    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.

  • Re:Um, no? (Score:4, Insightful)

    by jeremyp ( 130771 ) on Monday April 14, 2014 @11:55AM (#46748075) Homepage Journal

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

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