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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."
Probably not!
Trace a circle on the ground and drop stones at it.
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".
Except that, as a mathemitician, I know PI ~= 3.141592654. How does this help if you can only get to two significant digits?
-SaNo
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.
Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
In a post apocalypse zombie filled world I'd just say "3" and keep the shotgun shells.
We're still going to have those guns and know enough math, but won't remember what tau or pi is.
":...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
a gun to calculate Pi value...
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?
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.
jd
Number Theory With A Machinegun - The Problem Solving Powers Of The M2 Browning .50 Caliber Heavy Machinegun :)
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
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.
what's next? researchers use beads to do arithmetic?
Next up is "How to calculate gravitational pull of earth while taking a dump".
Alright boys, we used up all our limited ammo but at least we know pi before we die!
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...
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*?
My first program:
Hell Segmentation fault
We have only been using shotguns for fractions.
Do you put the zombies in front of the square alluminum plate?
My ism, it's full of beliefs.
In a post-apocalyptic world, why not fix the mistake and calculate the correct constant, tau?
Sounds like they undershot.
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....
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.
3.14159265358... or something like that. That could be wrong. But my memory is usually worth "Good Enough" engineering.
... What the hell do I do with this shotgun again?
And I think it's a lot harder to remember
We should learn what we need to know about issues, before we decide what we need to feel about them.
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.
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.
"File to fit, pound to insert, paint to match" - Aircraft Maintenance 101
" 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
"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
Expect this to be mentioned at the next military budget meeting.
If shotgun was unloaded at group of mathematicians then it would be very useful to our society.
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, 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..
Measure the diameter and circumference then divide with a slide rule. And get off my lawn.
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.
Hoist Number One and Number Six.
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?
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?
never bring a twinkie to a food fight.
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!
"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.
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.
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.
Slashdot - News for Nerds, Stuff that Matters, in ISO-8859-1 Has just realised that beta makes this signature redundant
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/
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?)
Another method :
http://en.wikipedia.org/wiki/B...
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
As an American, I also use a gun to balance my checkbook, shred potatoes, and call my kids to dinner.
Yee Haw!
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.
So - these mathematicians need to know Pi, and can remember this complicated way of working out a rough estimate, but can't remember (say) that 22/7 is pretty close? Hmm.
Probably best to take that shotgun away from them before they start, folks...
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".
yep, sounds like numerology bullshit alright.
This method of calculating pi using by counting random hits on a circular area is very old. I remember writing a computer programme to do it back in the 1980's using the in-built random number generator: Just keep picking random points on a plane between (-1,-1) and (+1,+1) and count the percentage of them that fall within the unit circle. I certainly didn't come up with this myself it was old news even then.
Doesn't this rely on some rather shaky assumptions, mainly that the spread of the shotgun pellets across the target is completely random (which we know it isn't; the likelihood of a pellet hitting diminishes as you move away from the centre)?
Darn. That method came up with 3.13, but I've already had 3.14 tattooed to the bottom of my foot...just in case...
Take a string say 100 times the distance from your toe to your heel. Let's call this 100 feet. Tie one end to a peg stuck in the ground and the other end to your belt buckle. Now walk in a circle keeping the string taught putting your feet down toe to heel.Count steps, divide by 200 and you've got pi. Even if you don't count the fraction of a foot left over it has to be accurate to better than 1%. You can keep the cartridges for the zombies.
If it's really a worry, tattoo pi somewhere discrete while you can remember it...
http://en.wikipedia.org/wiki/B...
#exclude <ms/windows.h>
... that the Ancient Greeks managed to do better at calculating Pi, all without shotguns!
...they could take the same sheet of aluminum, weigh it, cut along the arc that they already inscribed and weigh the quarter circle, and multiply the ratio in the weight by four. Or, they could take a length of string, carefully line it up with the arc they already inscribed and snip it, form the ratio of its length $\pi R/2$ and the length of a side of the square R, and multiply by 2. Or they could evaluate using any one of a number of summed series. Or any of a number of other measurement-based geometric arguments, most of which will be more accurate than Monte Carlo done with a Mossberg "corrected" by arguments that are surely more abstruse than summing a series.
If one absolutely insists on computing pi using homemade Monte Carlo, you might as well toss hot dogs:
http://www.wikihow.com/Calcula...
Or toothpicks, if you want a bit higher resolution. With a large enough target grid and a good enough "random toss" one can once again avoid needing to "correct" for the non-uniform distribution of pellets in a shotgun blast.
rgb
Even when the experts all agree, they may well be mistaken. --- Bertrand Russell.
Apocalypse, eh?
I would probably be using the mathematician standing in the corner wasting shotgun shells calculating Pi as bait during the next zombie attack.
Just sayin.
Unless solar powered calculators magically disappear
and people forget about how to use string and rulers.
Doesnt this assume the shotgun shells follow a truly random distribution?
http://montecarlopi.scienceontheweb.net
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.
If I fired both barrels at the same time would it equal Pi Squared?
Shooting arrows should work just fine, too, as long as you really don't know how to shoot.
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.
Do you have ESP?
OK, the rope won't do as much for accuracy as actually working out the math a bit, but nevertheless it WILL be better and more guaranteed result than a shotgun.
:-P )
Also, if you can curry a shotgun for the post-apocalyptic world, you can as well carry a clay tablet with "355/113" written on it and save on the bullets for the moments that you will be in higher need... (having a monopoly on circular constructions might make you a highly sought target
Nope. You're just presenting a more subtle version of numerological bullshit.
Having only one significant digit means that the actually value for 10 is somewhere between 6 and 14 and the value for 30 is somewhere between 26 and 34. Measurements were not that inaccurate (you don't really think they only have a 15 foot rope to measure with and absolutely nothing else, do you?).
10 and 30 have 2 significant digits even if you assume that they rounded to whole numbers and didn't want to use fractions or decimals. Rounding to whole numbers, a circle with a measure of 10 cubits across will measure 31 cubits around.
That passage of the bible is incorrect. Period.
you could just use a fucking piece of string and a piece of wood
tie wood to string
hold string down and draw a circle
measure circumference of circle with string
pi = circumference in strings / 2 strings
HOLY SHIT AM I A WIZARD
I can think of more important uses for ammo in the post-apocalyptic world.
If you have a shotgun, you don't need to know the value of pi.
guess I'm not going to walk into a wilderness roadhouse with my canoe hat and shoes, and start talking about the Laffer curve...
if this is supposed to be a new economy, how come they still want my old fashioned money?
..is that it could potentially lead to a great one-liner in a movie:
While raising a shotgun and preparing to fire...
"I'm doing a Monte Carlo approximation.. on your FACE!"
-- Senior Software Engineer, Attorney appearance services, locallawyerapp.com.
you are assuming a uniform distribution of holes. generally there should be more holes in the center of what you are aiming at. i guess you could assume a gaussian distribution of holes, but then you might need to use a zombie calculator.
They tell me with one of those babies, you can cut the lawn in one quarter the time at get more of the Pre-Game Show.
When I use a Mossberg 500 Pump-Action shotgun to calculate pi I measure the circumference of the barrel and divide it by the diameter. When measured carefully, it get's pretty damn close to 3.14.
That was the turning point of my life--I went from negative zero to positive zero.
My original version was . . . Your brother-in-law suggests using a shotgun to remove tree branches beyond your ladder . . . and you think it is a great idea!
Isn't this the first method you learn in Monte Carlo Methods ? Do we know the shot gun blasts are really random ? I suspect the blasts are biased towards the center.
The clerk finally shows up after numerous pages on the store loudspeaker, opens the case, and then there is a lot of pointing and pantomine as I try to explain, no, not the 16 gauge, I need 20 gauge, and no, not the 8-shot, I need the 6-shot, until we zero in on the right ammo. Out in the country, you can't let Mr. Romney's "varmints and critters" dig holes in your shingles and bust into the attic. Mr. Romney got a lot of flack from Real Men about not being a Real Gun Owner, but those of us who own property in the sticks know what he was talking about.
The clerk asks, "Um, how many boxes do you want?"
I say "just one", saying to myself, "How bad a shot do you think I am?"
But . . . all of us geeks already have memorized pi to more than 2 decimal places, so calculating it out is unnecessary.
It's 3.1415926535897932384626
I heard the Wisconsin Governor wants to procure pontoons from Oshkosh Truck in case the Michigan governor drops the Menominee river spans, but crossing Lake Superior northward poses a bigger challenge . . .
Never happened -- the guy with the textual analysis has it right.
So they shot up all their ammo to calculate something they already knew, and when the zombies came they were out of ammo. Are we sure this is clever?
355/113 is more than enough significant figures for me.
Hell, without a calculator I'll probably be better off using 22/7...
I first did this "dots in a circle" calculation for pi with a year 8 class over 30 years ago using 4 digit random numbers. Multiply the numbers by 10 000 so that they are all bigger than 1. Split the numbers in half to make an ordered pair from each one. Plotting them on a 0 - 100 plane with a circle radius 50 drawn on it. Determine the ratio of dots inside to outside the circle etc etc.
n/t
says someone who doesn't understand the written language. Numbers and letters were not separate.
Don't complain about syntax, grammar, or spelling. There is no.hell like input on android.
3.
14159
26535
8979
323846
This is the easiest grouping of digits, I find, to remember the first 20 digits. This gives you a level of precision far beyond anything anyone would ever need for any actual real-world calculation. Ta-da, problem solved.
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.
.
Prisencolinensinainciusol. Ol Rait!
uhh ... I'm a math professor. Why the hell would you waste time memorizing something you could look up. I think it's in the first chapter of CRC until aroudn edition 30.
I found this somewhere recently:
# let us consider the point c=(-0.75,X) of the complex plane, that is a point straight over the "neck" of the Mandelbrot set.
# Let n be the number of iterations from which the characteristic quadratic sequence of the Mandelbrot set Z(n+1)=Zn^2+c with Z0=-0 diverges (Zn2). With X being smaller and smaller we have: lim(X * n) = pi
So, I guess we have to figure out how to do recursive relations with a shotgun. (speaking of rednecks and relations... wedding...)
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
It has been done in the 18th century with a needle (see here). So you can save a few bullets (even if pump guns are not very useful against zombies they may be useful against looters) and more importantly avoid attracting every zombies in the neighbourhood.
Imagine the following scenario. The end of civilization has occurred, zombies have taken over the Earth and all access to modern technology has ended.
go on...
The few survivors suddenly need to know the value of pi
...no.
That sounds like a recipe for landing yourself on the Homeland Security and NSA watch lists ASAP!
Yeah, as a shotgun. You'll need that to calculate PI like a hole in the head, which you'll have if you don't save those shells for defending yourself.
It tells you about how big the bowl was.... which was the whole point. If we need the value of pi God doesn't need to give it to us, he already gave us a brain to figure it out for ourselves.
Ever since reading about it in high school programming class, every time I've learned a language I've written a Monte Carlo PI calculator in it - it's my hello world. It does seem odd that they got this close - I usually needed mega-iterations to get to 3.14, but that may be a function more of the weak PRNGs on most of the platforms I used.
seg fault
I don't think he was suggesting that they literally applied the theory of significant figures to the verse. It's just a lack of an attempt at greater accuracy and the description was likely adequate relative to the measures in use at the time given that the cubit was typically defined as the length of a man's forearm.
Anyone who tries to derive mathematics out of a passage like that is grasping at straws. It's a tour guide level description of interesting stuff, nothing more. Here's the passage in the Anonymous Coward version:
Tour Guide: And there's the great sea. It's ten cubits across and thirty around!
Crowd: Ooohh, Ahh!
Tour Guide: And on the right we see...
i didn't realize the impact of one significant digit. honestly i didn't believe 10 would be between 6~14 until converting to sci notation. (1e1 could be .5e1 rounded up or 1.4e1 rounded down). thank you for that insight.
however there are still trivial ways to account for this error.
1. Rounding error: d=9.6, c=30.16
2. Not a perfect circle. Any deviation from perfectly circular will reduce ratio of longest axis to circumference. (of course they would measure across the widest point!)
google calculator" makes this easy.
primary axis (diameter)=10; secondary axis=9.4; circumfrence=30.48
3. Lies! (this is to be expected in the bible): axis=9, 9.6; c=29.22. people would "round"(exaggerate) this slightly flat circle to "10 across; 30 around"
One man's "inaccurate" is another man's "good enough".
30/10 is pretty damn close to pi. It's not like 22/7 would be "correct", and if you think the Hebrew Bible should have even attempted to explain irrational numbers to a largely illiterate people, you're the one that's "incorrect".
That being said, numerology is hilarious. Sure, Hebrew numerals are written using the same characters as some Hebrew "letters" (I use that term loosely, as Hebrew uses an abjad, not an alphabet). Sure, it might be possible that summing some arbitrarily chosen subset of characters from that verse might yield 31, and summing some other arbitrarily chosen subset of characters might yield 222. However, nowhere in that verse does it indicate which subsets to sum (hence my use of the word "arbitrarily"). Also, nowhere in that verse does it say anything about dividing (or multiplying, or exponentiating, or performating any other binary mathmetical operation) one sum by another. The fact that you can apply some arbitrary interpretation to this verse and arrive at a decent approximation of pi doesn't mean anything, since I can come up with countless other arbitrary (but equally valid) interpretations that yield meaningless numbers that don't correspond to any particularly interesting natural constants. I don't know anything about this Chuck Missler, but based on the fact that he had this diatribe published under his name, I'd have to guess that he's an idiot.
Disclaimer: I'm an atheist.
Chuuch. Preach. Tabernacle.
wrong. 10 and 30 have 1 significant digit each. also, in your weird world, what happened to 5's?
According to 1 Kings 7:23, the circumference of a circle is equal to three times its diameter.
What will people not do to get an IgNobel Prize?
If it weren't for deadlines, nothing would be late.
He has recited pi to the last decimal digit. Twice.
He doesn't even need a Mossberg 500. He just tells a circle to fucking square itself.
If it weren't for deadlines, nothing would be late.
The reason they used 1 significant figure has nothing to do with measurement error. It's because no one bothered to recall more than 1 significant figure. They might have known that the thing was 9 cubits and 2 handbreadths across, but does anyone really care? No. So just write "10 cubits" and be done with it. It's easier to remember, which is important when you're trying to pass down traditions about the former glory of your people.
Almost every measurement in 1 Kings is given to 1 significant figure. There are two exceptions: the heights and circumferences of the pillars of brass. But that's it. The same is true of other books of the Bible -- the dimensions of the ark, for example, are 300x50x30.
In related news, John Carmack is using a BFG 9000 to compute the square root of -1.
I think maybe it's not about the shotgun itself, but more about the proof. The basic part is pretty easy to understand, and I'm pretty sure is already a known method for determining pi, and is useful for teaching math students about different ways of calculating pi. The abstract hints that there are methods of mitigating the less-than-fully-random nature of the shot spread, which is the only bit that seems paper-worthy to me.
One of my favorite statistical methods of determining pi involves dropping sticks over a ruled surface. The derivation is quite interesting, although still not useful in a post-apocalyptic world where we have forgotten so much that no one remembers a good approximation to pi.
Can you be Even More Awesome?!
That passage of the bible is incorrect. Period.
Of course the fact that it was 3 was in the interest of the church, it's not an accidental mistake or sloppy fact checking, they simply liked the idea that god created everything in nature using perfect natural numbers. There was no need to describe the circumference to start with, the 10 cubits across and the fact that it is circular is enough to let the reader know how big it was, the addition of the 30 is just religious poetic freedom.
The bible is not a scientific book and shouldn't be presented as such, it is not meant to be an accurate reference for units and natural constants. I'm sure the herder who needed the build a 10 steps sheep's pen figured out he needed 31-32 steps of fence.
In about 250 BC, the Greek mathematician Archimedes figured out that you could inscribe and circumscribe polygons on a circle, calculate the length of the polygon, and get an upper and lower bound of pi. He was accurate to 1/1000.
Plus it's not like they had proper machining tools to craft that thing with. When it's that big across it can look well enough like a perfect circle while not at all being a perfect circle. So even at that it would well have been a 3:1 ratio with imperfections in its execution.
I thought it was a common knowledge.
Why not just put peebles uniformelly distributed on a quarter of a circle inscribed on a square and use the same method?
you will only need a good hand, a stick, and some peebles.
You could get a better result with a tape measure and long division...
Pi = "three and a bit"
Or, wrap a tape measure around a tin can, and then stretch it across the largest distance from lip to lip. Divide one into t'other.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
Hi Internet,
I'm one of the coauthors of the article and we are not mathematicians, but physicists, let it be noted. Moreover, we did a movie about this
https://www.youtube.com/watch?v=QMgrDT4efPQ
It's in french, but worth checking out!
Calculate Pi in 10 steps without Guns, only Zombies!
Step 0: Kill a zombie by removing its head or destroying its brain. In a pinch you can lure one up high and shove it to the ground below.
Step 1: Detach one of the bigger bones of the arm or leg. If you have access to a cooler or are far enough north or south you may use the whole frozen zombie.
Step 2: Create your unit of measure. Detach a small straight segment of zombie -- the little bone at the end of the hand or foot will work. This will be our Zinch.
Step 3: Spin the larger zombie part while anchoring one end to create a circle of blood upon a flat bit of ground.
a. If the ground is uneven and you have only the corner of a wall, stand the zombie part in the corner and let it fall over to create a quarter circle arc.
b. Repeat 3a if you have a flat wall but no corner, falling the other direction to create a half circle.
Step 4: Place the Zinch on the edge of the whole, half, or quarter circle. Count the number of Zinches along the perimeter of the circle or arc.
a. For a quarter circle arc multiply this zinches by 4.
b. For a half circle arc multiply the zinches by 2.
Step 6: Count the number of Zinches of the larger zombie part. This is your Radius.
Step 7: Calculate Pi using the Radius and Circumference from step 4:
Circumference = 2 * Pi * Radius;
Thus:
Pi = Circumference / (Radius * 2).
Step 8: For accuracy, each Mathematician present should repeat the above with a different zombie / zinch then average your values.
Step 9: Congratulations! You have managed to distract all of the other Mathematicians long enough for them to be eaten by Zombies!
Step 10: Enjoy rebuilding society using the superior Tau constant!
There are Tau radians in one circle
Tau = Circumference / radius
Must not have done well in physics class? Back in my day we learned how Pi was derived in geometry!
Rawr
I thought we were beyond this. Some time ago cosm did some research before submitting something similar.
http://science.slashdot.org/comments.pl?sid=2572348&cid=38357478
Can't say I'm new here..
And all you morons wouldn't simply remember that pi=3.14? I'm fairly confident that will suffice post apocalypse till we have time to reconstruct Ramanujan's series for pi.
This is not math, this is engineering, which is a field I care about even less, yet:
Given the nature of the cubit unit (whose forearms were used? how many people contributed to the measure?) and the way of measuring (how straight was the line of forearms? did they use marks? were they really perpendicular when marking and looking at the marks?....) the results are:
Shotgun Pi = 99.67%
Bible Pi = 80% to 110%, and those who claim that thing approximated Pi to a billion decimal places can't be proven wrong.
OTOH the exact value of Pi in the Bible and the universe collapsing over the mass of an infinitely long book would have been quite a sight.
---- MISSING MISCELLANEOUS DATA SEGMENT --- [sigdash] trolololol
1 cubit is approx. 18".
10 cubits is approx. 180".
1 handspan is approx. 4".
30 cubits is approx. 540".
so, 10 cubits, less 2 handspans, is approx. 172".
540"/172"=3.14, to 3 significant digits. Ignoring significant digits, error works out to about 1/3", or about .07%
It all depends on how it's shaped, and where they measured it.
They're physicists...
22/7 is much closer - off by 0.04%
--
Simplicity isn't as simple as it used to be.
There's no need to waste ammo or even go all Monte Carlo on this problem, especially if you have a reliable source of cheap, low-grade meat. http://www.wikihow.com/Calcula... Read here about the grandfather of the above tutorial, the Buffon Needle Experiment: http://mathnexus.wwu.edu/websi...