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Mathematicians Use Mossberg 500 Pump-Action Shotgun To Calculate Pi

samzenpus posted about 3 months ago | from the less-common-core-math dept.

Math 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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311 comments

Would they have come to the same conclusion withou (0)

Anonymous Coward | about 3 months ago | (#46746533)

Probably not!

fixing the parent posting (0)

Anonymous Coward | about 3 months ago | (#46746553)

Would they have come to the same conclusion without prior knowledge of the numeric value?

Probably not.

My guess is they aborted their series of measurements when their results were "close enough".

Re:fixing the parent posting (1)

MrNaz (730548) | about 3 months ago | (#46746773)

I don't think they'd need to game it that much. They'd need a random dispersion of a large number of holes on that square to achieve the result, and I don't think that getting close to that ideal would be difficult given a large number of discharges at the target using fine shot shells. The law of large numbers would be in their favour.

Re:fixing the parent posting (1)

MrNaz (730548) | about 3 months ago | (#46746789)

Oh yea, and also... They would not need foreknowledge of the desired value as the ratios they use are sound. They would only need confidence in the random distribution of holes in the target.

Re:fixing the parent posting (5, Interesting)

mlts (1038732) | about 3 months ago | (#46746975)

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

Drop stones in a circle (2, Insightful)

Anonymous Coward | about 3 months ago | (#46746543)

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

First (-1)

Anonymous Coward | about 3 months ago | (#46746545)

First

Um, no? (0)

sanosuke001 (640243) | about 3 months ago | (#46746563)

Except that, as a mathemitician, I know PI ~= 3.141592654. How does this help if you can only get to two significant digits?

Re:Um, no? (1)

Dancindan84 (1056246) | about 3 months ago | (#46746701)

That's what I was thinking. I'm not rain man and I know it to 6 significant digits off the top of my head, which is 6 9's accuracy. Most people estimate it at 3.14, which is still more accurate.

This just screams of mathematicians pretending to be engineers.

Re:Um, no? (1)

MightyYar (622222) | about 3 months ago | (#46746801)

Nonaya eggheads is gonna last through the zombies, man.

I think the article is firmly tongue in cheek. There is no practical use here, but it is a fun way to teach some fundamentals of geometry and statistics.

Re:Um, no? (5, Interesting)

Dancindan84 (1056246) | about 3 months ago | (#46746841)

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."

Re:Um, no? (3, Insightful)

LordLimecat (1103839) | about 3 months ago | (#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.

Re:Um, no? (0)

Anonymous Coward | about 3 months ago | (#46747023)

Possibly it could be that the turnaround at each end of each linear leg is inefficient.

Re:Um, no? (1)

Dancindan84 (1056246) | about 3 months ago | (#46747105)

Yeah, I was unclear about that too, but it was easier to point out how ridiculous it was the way I did rather than getting into acceleration and turning velocity vs. straight line velocity.

Re:Um, no? (2)

noh8rz10 (2716597) | about 3 months ago | (#46747163)

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

Re:Um, no? (0)

Anonymous Coward | about 3 months ago | (#46746721)

I'm a non-mathematician who is monumentally bad at remembering numbers, and I can remember 3.14 for Christ's sake.

Re:Um, no? (1)

Anonymous Coward | about 3 months ago | (#46746753)

Except that, as a mathemitician, I know PI ~= 3.141592654. How does this help if you can only get to two significant digits?

The last time that I needed pi for anything it was for calculating the volume of a cylinder. I used the value 3.0 for pi as I had built the cylinder myself out of cardboard and I know my accuracy with scissors well-enough to realize that to use any more digits of precision would be just fooling myself. "Around 3-ish" is just about the precision that you need for everyday purposes.

Re:Um, no? (1)

Anonymous Coward | about 3 months ago | (#46746911)

Except that, as a mathemitician, I know PI ~= 3.141592654

Really? Because as a mathematician I know pi as a constant and the particulars don't matter.

How does this help if you can only get to two significant digits?

Because, for a lot of engineering, that's all you need.

Re:Um, no? (4, Funny)

JaredOfEuropa (526365) | about 3 months ago | (#46747013)

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...

So handy (1)

oodaloop (1229816) | about 3 months ago | (#46746573)

That's better than the part of pi I have memorized, 3.1415926. I had no idea I could waste valuable shotgun shells calculating pi to such precision.

Keep the shells (5, Funny)

Anonymous Coward | about 3 months ago | (#46746579)

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

Re:Keep the shells (1)

Anonymous Coward | about 3 months ago | (#46746897)

Or use the shotgun itself to sweep out a circle of diameter "1 shotgun" and place shells around the perimeter thus estimating the circumference as "x shells". You can then use the shells to measure the length of the shotgun to get a conversion ration between the two units. For garter accuracy you can use a longer gun and or smaller ammunition, and/or use the gun to sweep out a radius instead of the diameter.

One advantage to using the US system of measures is you get comfortable with units based around the "whatever some dude had in his pockets at the time" standard and converting between arbitrary systems for measuring the same thing.

Re:Keep the shells (1)

JustOK (667959) | about 3 months ago | (#46746981)

For garter accuracy...

Why not use an elastic garter?

Re:Keep the shells (3, Funny)

plover (150551) | about 3 months ago | (#46746927)

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.

Just forgettings things (1)

Anonymous Coward | about 3 months ago | (#46746581)

We're still going to have those guns and know enough math, but won't remember what tau or pi is.

um.... (5, Insightful)

johnholstein (1735990) | about 3 months ago | (#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

Re:um.... (1)

ameen.ross (2498000) | about 3 months ago | (#46746865)

What's more, if you are able to remember the details of the experiment, you are more than capable of remembering a few decimals of what is probably the most widely known constant in mathematics.

Re:um.... (0)

Anonymous Coward | about 3 months ago | (#46746889)

Any supposed mathematician who didn't know PI out to many digits must have a serious problem with their brain, and it would be confirmation if they suggest wasting that much ammo on such an experiment -- i.e. they are probably well on their way to being a zombie.

"Sorry, 3.14 will do." BLAM!

But... (-1)

Anonymous Coward | about 3 months ago | (#46746903)

... the people you're dealing with are probably American public school graduates, so they don't know that. You tell them "bring 10,000 rounds of ammo and 6 ham sandwiches to my tent and I can give you one decimal place."

Re:um.... (1)

multimediavt (965608) | about 3 months ago | (#46747111)

":...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

Yeah, and how hard is it to divide 22 by 7 with a twig in the dirt, "Mr. Mathematician"? That's also an acceptable approximation of Pi that is 4.0249943477E-2 percent off the "true value". I think the colder climate and/or recreational hallucinogens has slowed those Canadians' brains a might. Maybe that's the way to avoid zombies, after all.

Only in America... (5, Insightful)

Max_W (812974) | about 3 months ago | (#46746587)

a gun to calculate Pi value...

Re:Only in America... (3, Funny)

Nidi62 (1525137) | about 3 months ago | (#46746641)

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.

Re:Only in America... (1, Troll)

ArcadeMan (2766669) | about 3 months ago | (#46746705)

With the Conservatives acting like dictators and making bullshit pro-corporations, anti-people laws, I hope Québec splits soon enough.

Then it will pave the way for the USA to let Texas and California go their own separate way, too.

Re:Only in America... (1, Insightful)

Anonymous Coward | about 3 months ago | (#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.

Re:Only in America... (0)

c (8461) | about 3 months ago | (#46746795)

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

I'd be tempted to accept annexation just for the entertainment of watching the Quebecer's try to pull their entitlement nonsense with the US government.

Re:Only in America... (1)

marcello_dl (667940) | about 3 months ago | (#46746833)

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

Re:Only in America... (0)

CanHasDIY (1672858) | about 3 months ago | (#46747017)

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...

Re:Only in America... (0)

Anonymous Coward | about 3 months ago | (#46747041)

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

And I can tell that you are a girl because the ancient meaning of which was any virgin child.

Re:Only in America... (0)

Anonymous Coward | about 3 months ago | (#46746647)

Your reading is amazing.

"According to a couple of Canadian mathematicians"

Re:Only in America... (4, Funny)

cold fjord (826450) | about 3 months ago | (#46746661)

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

Re:Only in America... (1)

Anonymous Coward | about 3 months ago | (#46746937)

True, but since this empircally derived, the metric fans won't go for it.

Re:Only in America... (0)

Anonymous Coward | about 3 months ago | (#46746671)

Only in America do people not RTFA.

"...the work of Vincent Dumoulin and Félix Thouin at the Université de Montréal in Canada"

Canada is not America.

Re:Only in America... (1)

Gr8Apes (679165) | about 3 months ago | (#46746779)

Sure it is, according to my map anyways, N America. Now, it is not the USA.

Re:Only in America... (1)

iapetus (24050) | about 3 months ago | (#46747037)

So, Americans fail at maths and geography.

I'd feel smugly self-satisfied about that if it weren't for the fact that they clearly win in the impending zombie apocalypse.

Re:Only in America... (1)

DeathToBill (601486) | about 3 months ago | (#46746809)

Last time I checked, actually, it is. It's just not in the USA.

Re:Only in America... (0)

Anonymous Coward | about 3 months ago | (#46746859)

Yes, that's exactly what I thought, before checking where it has been "calculated"...

Canada ?
Well, that's still in America continent, isn't it ?

Re:Only in America... (0)

Anonymous Coward | about 3 months ago | (#46746873)

What's wrong with this is that the gun loving Quebecois aren't taking God's word that pi is 3.

He made the Sea of cast metal, circular in shape, measuring ten cubits from rim to rim and five cubits high. It took a line of thirty cubits to measure around it. 2 Chronicles, chapter 4 verse 2.

Re:Only in America... (0)

Anonymous Coward | about 3 months ago | (#46746893)

I can see Chuck Norris and MacGyver shaking hands after the experiment.

Re:Only in America... (1)

multimediavt (965608) | about 3 months ago | (#46747169)

a gun to calculate Pi value...

Not only are they Canadian, they're French Canadian. Calling them American is worse than calling them Canadian as the Québecers would rather be their own country all together. I just think they're smoking something to not use simple long division to calculate Pi, especially as a university research mathematician. I mean, really! 22 / 7 = closer to Pi than their stupid shotgun embarrassment.

Ask an old person? (4, Insightful)

gb7djk (857694) | about 3 months ago | (#46746593)

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?

Re:Ask an old person? (4, Funny)

Roxoff (539071) | about 3 months ago | (#46746703)

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

Re:Ask an old person? (0)

Anonymous Coward | about 3 months ago | (#46746899)

I believe "Euclid's Shotgun" was his prerogative to always sit in the front passenger side of the chariot.

Re:Ask an old person? (1)

Anonymous Coward | about 3 months ago | (#46746731)

Being an engineer I lost interest at mapping out an arc. If I have a piece of string or whatever to map out that arc then I have plenty of tools to approximate pi with without the need for a shotgun.

Re:Ask an old person? (1)

DeathToBill (601486) | about 3 months ago | (#46746823)

I thought the engineer's answer was, "More than three and probably less than twenty."

Oh, no, wait, that's the answer to "What's 2+2?"

Re:Ask an old person? (2)

Kjella (173770) | about 3 months ago | (#46746971)

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.

Re:Ask an old person? (1)

cold fjord (826450) | about 3 months ago | (#46747099)

Rhetorical question: I wonder how Euclid managed?

Slingshot. It is a slower process but still provides a useful answer when under primitive conditions.

Waste of shells (0)

Anonymous Coward | about 3 months ago | (#46746605)

I'd prefer to save the shells for the zombies personally. Besides 22/7 would give a far more accurate result if you can't remember it exactly.

Really? (1)

Jager Dave (1238106) | about 3 months ago | (#46746607)

Sounds like a perfect waste of ammunition... Zombie Apocolypse? HELLO?

jd

I think I just found a title for my thesis (1)

cold fjord (826450) | about 3 months ago | (#46746615)

Number Theory With A Machinegun - The Problem Solving Powers Of The M2 Browning .50 Caliber Heavy Machinegun :)

Re:I think I just found a title for my thesis (3, Funny)

i.r.id10t (595143) | about 3 months ago | (#46746629)

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

Re:I think I just found a title for my thesis (1)

Xest (935314) | about 3 months ago | (#46746947)

If you mount it on a sliding rail running parallel to and pointing at an infinite length horizontal board with an infinite belt of ammo and set it moving with a correctly calibrated exponentially increasing speed then you can use it to reproduce, using a measurement of the distance from the start, the Fibonacci sequence.

Useful if you're in a zombie apocalypse and you need to remember it.

Do I get my own Slashdot article now?

easier way (1)

SemperUbi (673908) | about 3 months ago | (#46746631)

I would just approach my fellow humans with the Mossberg 500 and ask if anyone remembers the value of pi. I live in Silicon Valley: even the zombies would remember it.

Re:easier way (1)

SemperUbi (673908) | about 3 months ago | (#46746665)

And as a mathematician, I would already remember more significant figures for pi than I would likely be able to get from a bullet-scatter pattern.

A really slow news day (1)

Lawrence_Bird (67278) | about 3 months ago | (#46746633)

what's next? researchers use beads to do arithmetic?

Re:A really slow news day (1)

mysidia (191772) | about 3 months ago | (#46747165)

what's next? researchers use beads to do arithmetic?

Next article is on how to use paper logarithm tables to perform calculations in a post-apocalyptic world.

Good use of research money! (1)

Anonymous Coward | about 3 months ago | (#46746639)

Next up is "How to calculate gravitational pull of earth while taking a dump".

Re:Good use of research money! (1)

Anonymous Coward | about 3 months ago | (#46746747)

9.8 dookies per second per second

Re:Good use of research money! (1)

Captain Hook (923766) | about 3 months ago | (#46746891)

go see a doctor, like really urgently.

Sweet (2)

Terence J. Lindsey (3615705) | about 3 months ago | (#46746651)

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

Archimedes (2, Insightful)

Anonymous Coward | about 3 months ago | (#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...

Funding (1)

fph il quozientatore (971015) | about 3 months ago | (#46746683)

As a mathematician, the best part of it is probably asking your department to put the rifle on your research funds. I'm sorry, professor Dumoulin, you need *what*?

Huh. Who knew... (2)

TheRealSteveDallas (2505582) | about 3 months ago | (#46746691)

We have only been using shotguns for fractions.

I don't understand (3, Funny)

MrKaos (858439) | about 3 months ago | (#46746707)

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

Why calculate pi? (2)

Anonymous Coward | about 3 months ago | (#46746709)

In a post-apocalyptic world, why not fix the mistake and calculate the correct constant, tau [tauday.com] ?

Sounds like... (1)

RJFerret (1279530) | about 3 months ago | (#46746717)

Sounds like they undershot.

Zombie make it news? (1)

Anonymous Coward | about 3 months ago | (#46746757)

Really?? The Monte Carlo approximation has been around for over 50years...just because they calculate it "With a shotgun during a zombie apocalypse" doesn't make it news....

Re:Zombie make it news? (1)

JaredOfEuropa (526365) | about 3 months ago | (#46747109)

Good enough to be granted a patent on it.

Just weigh the target... (0)

Anonymous Coward | about 3 months ago | (#46746761)

then weigh the part of the target representing the circle. The ratio of the two pieces will give you the answer. Physicists used to use the paper-scissors method to calculate the area under a curve when all else failed.

Re:Just weigh the target... (1)

TheCarp (96830) | about 3 months ago | (#46746919)

I feel like this should be the gold standard. Whatever method you use, it should be either a lot cheaper or a lot more acurate; if neither, you chose very poorly.

You're writing this to geeks you know.... (1)

briancox2 (2417470) | about 3 months ago | (#46746777)

3.14159265358... or something like that. That could be wrong. But my memory is usually worth "Good Enough" engineering.

And I think it's a lot harder to remember ... What the hell do I do with this shotgun again?

2 tips for preppers (4, Insightful)

CQDX (2720013) | about 3 months ago | (#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.

What would a real nerd do? (1)

bobbied (2522392) | about 3 months ago | (#46746803)

A real nerd would know how to calculate Pi from scratch, no shotgun required...

Pi = (4/1) - (4/3) + (4/5) - (4/7) + (4/9) - (4/11) + (4/13) - (4/15) ... (keep going until you get the number of decimal places you need.)

Why bother with the shotgun and waste the rounds conducting this worthless experiment. You are proving nothing but that you know how to draw a square and an arc and count.

OR, just get some unsuspecting length of string, a ruler and a round object like a jar or large can. Measure the circumference and divide by diameter, voila! Pi.

from the abstract (0)

Anonymous Coward | about 3 months ago | (#46746811)

" thus opening up new perspectives towards computing mathematical constants using everyday tools. "

I wish somebody told me sooner that I should keep my shotgun with my everyday tools

So wait, shotguns are more accurate than the bible (5, Interesting)

netsavior (627338) | about 3 months ago | (#46746827)

"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

Re:So wait, shotguns are more accurate than the bi (3, Interesting)

garyebickford (222422) | about 3 months ago | (#46747157)

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.

Military Spending Justification (0)

Anonymous Coward | about 3 months ago | (#46746847)

Expect this to be mentioned at the next military budget meeting.

There is just one thing wrong in the test (0)

Anonymous Coward | about 3 months ago | (#46746849)

If shotgun was unloaded at group of mathematicians then it would be very useful to our society.

No shotgun needed (0)

Anonymous Coward | about 3 months ago | (#46746879)

No shotgun needed:

1) If a simple linear rule is not available, make one based on an arbitrary unit.

2) Using some string and a ruler, measure the circumference and diameter of a circle (constructed by sweeping the string around a central peg).

3) Using a pencil and paper, divide the two measurments.

Do It Yourself: Al foil, shotgun, perminate-to-eac (1)

MonsterMasher (518641) | about 3 months ago | (#46746881)

Do It Yourself: Al foil, shotgun, stable-to-each mount for both (use multiple sheets to catch all pellets), scanner.

    the rest is just mathematics.. the shotgun spread, especially to the outsides make a nice pseudo-random number generator temples. Use all for maximum data. Not use a 'virtual' circle (actually as many as will fit of different sizes) and knowing the real value of pie you may use this to find the 'circle size that is best for this generator'.. for fun and extra credit.

That is how the Bill of Rights protects backyard science from being taken from us. Pretty soon rocketry science will not be possible, or radio controlled planes, as it's nearly a crime to blow things up for fun now! Science suffering..

use a piece of string (1)

tomhath (637240) | about 3 months ago | (#46746913)

Measure the diameter and circumference then divide with a slide rule. And get off my lawn.

Chokes (1)

Stargoat (658863) | about 3 months ago | (#46746931)

Shotgun pattern distribution is governed by several factors, including shot quality / material, wad design, barrel design, hull design, forcing cone length / shape, but most especially choke. Steel shot will rip up some chokes. Chokes can creep (particularly on a hot Illinois day). Wadding can foul a barrel.

I wonder if these were controlled for.

Re:Chokes (1)

CanHasDIY (1672858) | about 3 months ago | (#46747077)

Glad I'm not the only one whose first question involved the choke.

BTW, you forgot "windage" in your variable list.

Anyone know random the spread of the Mossberg is (1)

Chrisq (894406) | about 3 months ago | (#46746933)

The above would only work if the spread were random. I would expect it to cluster with a greater density of pellets in the middle. Does anyone know how random the spread is?

those damn sand-eating zombies! (1)

Connie_Lingus (317691) | about 3 months ago | (#46746993)

Dumoulin and Thouin’s idea is to use the distribution of shotgun pellets rather than sand or rice (which would presumably be in short supply in the post-apocalyptic world).

really...sand in short supply?

and shotgun shells aren't?

Better use for the shotgun? (0)

Anonymous Coward | about 3 months ago | (#46747011)

I'd use the shotgun to fend against zombies.... Every bullet counts!

Does knowing pi make your brain taste better for the zombies....? That's the real question!

Context (0)

Anonymous Coward | about 3 months ago | (#46747019)

"couple of Canadian mathematicians" = 2 physics students who did a movie about this and submitted it to an amateur film festival and then thought "hey, why not write a wacky science article about this, just for fun?"

While their math is sound, they are in no way seriously advocating that this is how you should estimate Pi in any circumstances.

Just weigh the aluminium target (1)

jrifkin (100192) | about 3 months ago | (#46747039)

Swap the gun for some tin snips and a scale. You could simply weigh the whole target, then snip out the quarter circle and weight that. Take the ratio of the weights, and you're done.

Save the ammo for something else.

dalaman transfer (-1, Offtopic)

light tour (3615727) | about 3 months ago | (#46747075)

we are the transfer company from turkey www.lighttransfer.net

Hmmm (1)

DeathToBill (601486) | about 3 months ago | (#46747127)

If you really want to use this method to calculate pi, here's how to actually go about it. What you need is a hundred yards or so of string, four stakes, a stick and something that's a reasonable approximation to a right-angle (perhaps a piece of a cardboard box salvaged from the apocalypse). If you're really stuck for a right angle you can construct one with three stakes and a piece of string by putting two stakes in the ground and using the string to mark a straight line between them, then tying one end of the string to one of the stakes and tying the third stake to the string, so that length of string between them is a bit over half the distance between the stakes in the ground. Mark out a circle using this. Then mark out a second circle with the other stake in the ground as the centre. These two circles will intersect at two places - use the string to mark a straight line between them. The two straight lines you have marked will be at right angles.

Now put two stakes in the ground, about 20 yards apart. Stretch string between them. Put your right-angled thing with one side against the string and the right-angle corner at one of the stakes. Measure another piece of string to be the same length as the piece stretched between the two stakes. Tie it to a third stake and stretch it out so that it runs along the other side of the right-angled thing. You've now marked out two sides of a square with string. Repeat to form the other two sides.

Take your stick and break it down to about a foot long. Use it to mark out on the ground equally-spaced marks along each side of the square. Get two people to hold each end of a fifth piece of string across the square so that you can mark straight lines on the ground, dividing the square into a grid.

Cut your fifth piece of string to be the same length as one side of the square. Tie one end to one of the stakes. Now use the other end to mark out an arc from one corner of the square to the opposite corner.

Count the number of squares that are inside the arc and the total number of squares. Take the ratio of these two numbers and multiply it by 4. Here is your approximation to pi.

This method has many advantages over the one proposed: With the dimensions given above, it gives a considerably better answer, correct to four significant figures (3.141). It is easy to scale for better accuracy - make the square 100 yards and the stick four inches and you get six correct digits (3.141590123). You don't need to correct for uneven shot pattern. And, crucially I'd say in an apocalypse, you don't need a shotgun or ammunition and, if you do happen to have them, you can use them for useful things like fending off the zombies or hunting.

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