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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."
Trace a circle on the ground and drop stones at it.
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?
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.
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.
"Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
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.
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.
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....
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.
I hate printers.
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.
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.
I hate printers.
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.
W..w..W - Willy Waterloo washes Warren Wiggins who is washing Waldo Woo.
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
"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
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
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..
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.
Measure the diameter and circumference then divide with a slide rule. And get off my lawn.
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.
"I opened my eyes, and everything went dark again"
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?
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.
I'm wondering if they got results without a choke, or at full choke. This might be statistically significant.
Or maybe they're smarter than you think:
https://www.youtube.com/watch?...
++ Say to Elrond "Hello.".
Elrond says "No.". Elrond gives you some lunch.
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.
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...
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.
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.
"Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
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/
or maybe your wife is tired of you talking to her like she's a child.
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
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.
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.
If I was talking to her like a child I would have said, "That's neat" and patted her on the head. I say stuff that's ridiculous and my wife corrects me without talking to me like a child, and vice versa. We can even do it with a little ribbing like I did in this case without getting butt-hurt about it. I actually find it hilarious when it dawns on me that I have one of those, "Oh @#$%, I just said something really stupid and she caught me," moments and I'm glad I'm in a relationship where we can poke a bit of fun at each other and enjoy it.
"Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
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...
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..."
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.
Ok, even if I give you that you can cut with a push mower while pushing down with the exact amount of force to just keep the weight off the front wheels, cutting your lawn in a series of circles would mean you have to keep that downward force applied for the entire duration of cutting your lawn. And you'd still get dizzy. The only way that would be acceptable is if you had Yakety Sax playing in the background while you mow and stadium seating for the show.
"Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
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.
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?
You should get your ears checked. Turning at a steady pace at walking speed will not make a normal person dizzy.
You do not have a moral or legal right to do absolutely anything you want.
When we rebuild industrialized society, I'll invent a precise means of measuring (something like a ruler?), some kind of calculating device (something like an abacus), and end up with an approximation sufficient to exceed the abilities of my tools to measure. Now, about fire and the wheel...
Yes, I know -somebody just wanted to talk about various interesting ways to approximate the value of pi. Ever consider dropping matchsticks on a leftover US flag?
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
The inefficiency actually comes in when you realize that most lawns are not circular. Something about square pegs and round holes, I think?
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
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.
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?
They don't talk about the choke specifically, but they do say... "The distribution of pellets is influenced by all kinds of factors, such as the height of the gun, the distance to the target, wind direction and so on. So this distribution is not random. To get around this, they are able to fall back on a technique known as importance sampling. This is a trick that allows mathematicians to estimate the properties of one type of distribution while using samples generated by a different distribution."
All kinds of questions are answered in TFA. I know, I'm new here...
Dear Slashdot: next time you want to mess with the site, add a rich-text editor for comments.
..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.
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
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!
Seriously - haven't we seen what happens when an egghead tries to use a real man's weapon in a zombie apocalypse? Disaster. But not quite as disastrous as walking straight into the earth's last NPR radio station without questioning why there's no guards, only five hipsters, and a whole lotta barbecue...
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?"
if you say so dear. now go back into the kitchen and fetch me a beer.
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'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.'"
I'm going to agree with Sarten-X - turning in a wide circle shouldn't get anybody dizzy.
Also, with my lawn mower I have a turning radius that I can maintain without lifting the wheels at all. So at least the first few loops I wouldn't need pressure at all.
It also depends on how you define 'most efficient'. If the extra effort of pushing down a bit is outweighed by the time saved, it may we worth it.
On trick I've used in the past is to not turn the mower around - after clearing around the fence a bit, after pushing forward you pull the mower back.
I don't read AC A human right
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.
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.
Let's consult the NIST algorithm, shall we? ;-)
"Flyin' in just a sweet place,
Never been known to fail..."
I'm wondering if they got results without a choke, or at full choke. This might be statistically significant.
No, they actually correct for the "non random" spread of pellets in the paper using importance sampling. Which is a neat trick and really the takeaway from this paper. I.e. that you can make Monte Carlo methods work, even if you don't have a flat/uniform probability distribution.
Stefan Axelsson
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!
Well, if you have a, say, rectangular lawn, and you start making a circle -- imagine the Japanese flag with the inner circle being bigger and touching the edges -- what then? How can you cut the four remaining separate (and very awkwardly shaped) corner bits while still coming out ahead?
Or maybe not a literal circle was meant, but more like going from the outside to the inside, in a spiraling fashion, with 90Â degree turns instead of the regular ones?
Or you could just remember 355/113, accurate to 0.000027%. Or, if you're happy with the accuracy of the shotgun solution, there's always 22/7, which is accurate to 0.13%
I'd put a random distribution of holes in his worthless head!
I believe you mean psuedorandom. (*bang*)
Would they get the same distribution with the same initial conditions? No, of course the wouldn't because quantum uncertainty underlays the interactions between component particles of the experiment. So it's a nondeterministic random distribution, not a pseudorandom distribution.
I should use this sig to advertise my book ISBN-13 : 978-1501515132.
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
Oh, man, does your wife do that to you too?
I hate it when she does that.
Lost at C:>. Found at C.
Or maybe they're smarter than you think:
https://www.youtube.com/watch?...
Hahahahahahaha there aren't enough +1s in all of youtube to express how cool that is...
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.
there actually is a cross-over point and it does depend on the shape of the lawn.
turns are inefficient because you actually need some overlap if you want to make sure each turn patch is completely mowed [as the mowed patch is typically round
Sleep your way to a whiter smile...date a dentist!
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 know about getting dizzy and all, but I will say that those cheap lawnmower wheels/bearings/mounts are unlikely to last very long if under constant horizontal forces.
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.
The square yard plan I had was to do increasing D shaped passes. So imagine a 30 by 30 lawn mower width field, you would start your North pass 10 lawn mower widths from the west edge, mow until you were 11 lawn mower passes from the North edge, and then make as tight of a 90 as possible, then drive 9 lawn mower widths to the East, then make as hard of 90 to the right heading back South, reaching 10 mower widths north of the South edge you would turn as sharp as you could back to the West. You would mow until you cross your first path, turning 90 to the right to mow to the west edge of that path. Then follow the left edge of your previous cuts until your done.
The point of this is to make sure you never get into following a path on the inside of a corner, because that will cause every corner to get tighter and tighter until you can't make the corner. This path you only double cut 1/2 that first pass (technically if you start your first path 10 passes in from each edge, you would never mow the spot 2*, you will end with a couple unmowed circles at each corner before you have to overlap to catch them up if truly square.
According to 1 Kings 7:23, the circumference of a circle is equal to three times its diameter.
> Goddamn mathematician wasting precious ammunition to have a statistics wank-fest after MY goddamn zombie apocalypse?
Yes, especially because you do not need to waste the shells if you are after an approximation. Get a string, trace a circle. Stretch the string across the circle, through the center, marked when you were tracing it. Measure the diameter string, in shells. Line shells around the circle, bases touching each other. Divide the two numbers, multiply by two, and you will get decent accuracy.
Of course, you will get better accuracy, if you stick 200 or so sticks on the circle's circumference, wrap a string around them, and measure that in shells.
And you can improve on that, by expressing the error for going straight between sticks using Pi, and solving the resulting equation.
But if you are actually able to do math, you can just use one of the series that converge on Pi.
No good deed goes unpunished...
What will people not do to get an IgNobel Prize?
If it weren't for deadlines, nothing would be late.
You are the best kind of correct.
Technically correct.
"Lack of speed can be overcome. In the worst case by patience." --Znork
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.
Its not, because some of the areas on the lawn are only hit during the turn-around. And with a circular pattern, you will HAVE to travel over-top of already-done areas in order to hit the corners of the circular path.
Trying to use a circular path to fill in a rectangular area will by necessity involve hitting areas more than once, or going outside of the rectangle.
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?!
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.
You could get a better result with a tape measure and long division...
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.
I'm assuming you mean small rocks, and not department stores, which would be much more difficult to drop on a quarter circle. (But not impossible with adequate preparation.)
The simplest answer to your question is "because shotgun shells go bang".
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
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.
[how could it be] more efficient?
How? You're obviously misunderstand the efficiency effect.
You laugh yourself silly watching that schools' math nerd cutting your grass in circles, falling over and finally throwing up. Bonus points if you fed him colored Kool-Aid beforehand or were tipping him to finish faster.
It's hard to get a good ROTF belly-laugh, and I can't think of a more efficient and cheaper way to do it.
If the universe is someone's simulation -- does that mean the stars are just stuck pixels?
You have the brain of a rodent.
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
And you waste a load of shotgun shells that are going to be extremely valuable in the post apocalypse.
Depends, the 20 gauge are plentiful but the lever action shotgun they go in is rare and breaks easy (single shotgun's reload speed is atrocious), the 12 gauge is rare, but the combat shotgun is even rarer. I'll stick to the cowboy repeater backed up with a 10mm SMG and varmint/hunting/sniper rifle for long range.
Calling someone a "hater" only means you can not rationally rebut their argument.
I thought you just divided 22 by 7...
Nos Morituri te salutamus
Thank you, Stilgar.
Tiller's Rule: Never use a word in written form that you've only heard and never read. You will end up looking foolish.
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
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...
Around 3-ish" is just about the precision that you need for everyday purposes.
Wow. I suppose that if you are dealing with very small circles - or just don't have much pride in your work it can sort of kinda work
As a simple example, if you have a 10 inch diameter circle:
3 x 10 = 30 inch circumference - or a
with a rough value of pi = 3.14
3.14 x 10 = 31.4 inches.
Or the difference between a 10 inch circle and one that is around 9 and a half inches.
The shepherds did so well protecting the flock that the sheep no longer believed that wolves existed.