Pi Day: How 3.14 helps find other planets, and more
iReporter Zeynep Rice made this pie to celebrate Pi Day.
March 13th, 2012
05:40 PM ET

Pi Day: How 3.14 helps find other planets, and more

Happy Pi Day! A favorite holiday among geeks, March 14 commemorates one of the most fundamental and strange numbers in mathematics. It's also Albert Einstein's birthday.

This is a great excuse to bake pies, as many iReporters have (send us your pie-report!). But there are also lots of reasons to celebrate this number: Pi  appears in the search for other planets, in the way that DNA folds, in science at the world's most powerful particle collider, and in many other fields of science.

Here's a refresher: Pi is the ratio of circumference to diameter of a circle. No matter how big or small the circle is, if you calculate the distance around it, divided by the distance across it, you will get pi, which is approximately 3.14.  That's why Pi Day is 3/14!

But the digits of pi actually go on forever in a seemingly random fashion, making it a fun challenge for people who like to memorize and recite long strings of numbers (like this iReporter). By the way, the world record for memorization stands at 67,890 digits, according to the Pi World Ranking List. Here are 10,000 digits to get you started.

To the uninitiated, such enthusiasm over a number may sound ridiculous. But when you think about how many different fields of science incorporate pi, it does seem kind of amazing.

Be forewarned: We're going to have to use a bit of math to explain why. Yes, math formulas may seem scary, but trust us: It's worth the challenge.

The search for new planets

For Sara Seager, professor of planetary science at Massachusetts Institute of Technology, pi is part of everyday work in characterizing and searching for planets outside our solar system, called exoplanets.

Here's her basic formula: The volume of a planet is about 4/3 pi times the radius3.

You need this formula to find the density of a planet, which is mass divided by volume. This number that tells Seager and colleagues whether a planet is mostly gaseous like Jupiter, rocky like Earth, or something in between.

Pi is also involved in calculations regarding an exoplanet's atmosphere, since it can be described spherically, and spheres always involve pi.

"Coincidentally, pi is useful to estimate the number of seconds in a year (on Earth): There are approximately pi times 10 million seconds in a year," Seager says.

And a tiny space telescope that Seager works on called the ExoplanetSat, which is a collaboration between MIT and Draper Laboratory, also incorporates pi in optics equations related to the telescope's mirror.

Astrophysics

Pi helps describe the shape of the universe, says David Spergel, chairman of Princeton University's astrophysical sciences department.

Spergel studies cosmic microwave background radiation, which is basically radiation that's still hanging around from the early universe - it's the afterglow of the Big Bang.

Using a spacecraft called WMAP (Wilkinson Microwave Anisotropy Probe), Spergel and colleagues have been able to get an idea of what the early universe looked like - a "baby picture," as it was called when WMAP's 2003 results were released.

See if you can wrap your head around this:

4pi is the ratio of the surface area of a sphere to the square of its radius, in geometrically flat space.

"Using our measurements of the microwave background, we measure this ratio by determining the angular size of hot and cold spots in the microwave sky. Our measurements show that the large-scale geometry of the universe is accurately described by the Euclidean geometry that we all learned in high school," Spergel says. "This measurement implies that the total energy of the universe is very close to zero."

Why? The positive energy from the universe's expansion (it's been expanding since the Big Bang) is balanced by the negative energy of matter being attracted to itself, via gravity.

The Large Hadron Collider

Pi comes up a lot in what physicists do at the Large Hadron Collider, the $10 billion machine at the European Organization for Nuclear Research (CERN) in Switzerland that smashes protons into protons at unprecedented energies. Scientists are looking for as-yet-undiscovered particles such as the Higgs boson, which popular culture refers to as "the God particle."

Joe Incandela, spokesman for the collider's Compact Muon Solenoid experiment, explains one way that pi shows up at the LHC:

In particle physics, if we can measure particle properties, like masses, very very precisely, we can sometimes find tell-tale evidence of undiscovered new particles. That’s because particles can transform themselves into other particles, and then come back together to make the original particle again. This is called a loop.

When you calculate the contribution of this process to the particle's mass, a factor of something like 1/(16pi2) comes out, along with other factors that depend on the properties of the particles in the loops.

Interestingly, prior to the LHC, some particles could only appear in these loops, and nowhere else, and should come in pairs in order for a special property that they have to be conserved. A very important example of a theory of particles with this kind of behavior is what scientists call supersymmetry, and it helps explain a lot of the holes in our current best understanding of the universe, known as the Standard Model.

Scientists are hoping to see these kinds of particles directly which requires very high-energy particle accelerators like the LHC to make them. They will also continue to try to detect their effects on Standard-Model particles in these loops, which are extremely short-lived and this requires a lot of patience because measurements must be extremely precise.

So, supersymmetry will probably still be out there for us to discover, even though there is no evidence of it in detailed measurements of particle parameters at the LEP and Tevatron accelerators in the past (or at the LHC either, so far, but there's still a lot of room to look for them).

Gravity, energy and mass

Pi appears in Einstein's equation for how energy and mass lead to the curvature of spacetime:

R_ij – (1/2)R g_ij = 8pi*G T_ij.

Wow, what is that? Sean Carroll at California Institute of Technology acknowledges that this is a weird-looking equation, but the important part is that G is Newton's constant of gravitation. "Long story short: in Newton's equation for gravity, the constant is just G; in Einstein's equation, it's 8pi*G," he says.

Why? Carroll explains:

Let's say you know how much mass the Earth has, and you want to figure out what the strength of gravity is at some distance away. Newton's equation tells you what that force is - it's proportional to one divided by the distance squared (the famous "inverse square law"). But let's say you want to do the opposite - you know what the force is,  but you want to figure out how much mass is causing it.

You could draw a sphere that completely surrounds the object, and add up the gravitational force at each point on the sphere, to make sure you are correctly capturing what's going on inside. So the answer to one question is related to the answer to the other, by adding up things all over a sphere. And the area of a sphere of radius R is 4pi R2. Voila - pi comes into the expression, because pi relates distances (straight lines) to spheres.

How DNA folds

Pi plays an important role in the way the genome is folded, says Leonid Mirny, associate professor at MIT.

"If you take all DNA of the human genome contained in a single cell and stretch it, the DNA would be a 2-meter-long fiber," he says. How are these two meters of DNA packed inside a cell nucleus, which is only 5 micrometers (that's 5 millionths of a meter) in diameter?

Think about thread around a spool. At the cellular level, there's a core made of special proteins called histones, and they're like the spool. DNA wraps twice around it and then continues to the next spool. Each one of these spools is called a nucleosome, and tens of millions of them pack our DNA, making it look like a string of beads.

How much shorter is this string than the DNA itself? The answer is about 1.5pi (or about 5) times!

Mathematics

Pi is essential for mathematicians whether they care about circles or not, says Jordan Ellenberg, professor of mathematics at the University of Wisconsin. Here's one place where it comes up for Ellenberg:

Choose two random numbers between 1 and 1,000. Then, he could compute whether they have any factors other than 1 in common. "It turns out that the probability of having no common factor is a a little over 60%," he says. "And you can change 1,000 to 10,000, and then to 100,000, etc etc, and amazingly the probability seems to be converging to a fixed value, about 60.79%. More amazingly still, this value is 6/pi2!"

Studying crickets

Crickets use sound to locate mates, and their reaction to fellow crickets' calls are of interest to Gerald Pollack - a biologist at McGill University in Montreal, Quebec. In one of his experiments, crickets walk on a spherical treadmill while a loudspeaker broadcasts a cricket song. How accurately do they walk toward the sound?

"We measure the discrepancy between the direction of the loudspeaker and the direction in which the cricket walks, both of which are measured as angles ranging between zero and 2pi radians," he says.

Magnetism

James Clerk Maxwell Maxwell published famous equations of electromagnetism in the 1860s. They are fundamental to modern electronics and communications.

These equations include an important physical quantity called "the permeability of free space," which has a value of 4pi x 10-7 H/m that's units per Henry per meter, where a Henry is a unit used in electronics.

"So we are all using pi every day when we think about magnetic or electric fields, or electromagnetic radiation (light, radio etc)," says Caroline Ross, associate head of the Department of Materials Science and Engineering at MIT.

Engineering

Pi is involved in calculating the surface area and volume of round three-dimensional objects. So, if you're planning to build something involving spheres or arches or some kind of circular geometry, you're going to need pi!

Drug design

Chandrajit Bajaj at the University of Texas, Austin, is researching molecular recognition models for drug design and discovery. She uses simulations of particles in which atoms are often represented as spheres. The formulas for molecular surface area and volume involve pi, and often appear in Bajaj's calculations.

So, there are more than 3.14 reasons that pi is special. Now go eat some pie!

Follow @CNNLightYears on Twitter

Post by:
Filed under: In Space • Math • On Earth
soundoff (212 Responses)
  1. Demetra

    What's Happening i am new to this, I stumbled upon this I have found It absolutely helpful and it has aided me out loads. I am hoping to contribute & aid other users like its aided me. Good job.

    April 17, 2013 at 8:50 pm |
  2. Virginia

    the error of.1 is 60% the error in 4 is 60% not of a whole number but in the smalles of measurement known to men kind but when multiplied by infinity it's large enough number to show in the shape of abject...cannot used 3.14 in social studies till the accurate number is found...i have no need to measure object here on earth or in the universe or on particle for that matter...so if i have an interest is for social studies reasons...3.14 pi needs more accuracy cause is smaller then paricle its quantum symetry or supersymetry measurement i am trying to achiave here...kindy like psychi prediction kind of a thing...

    March 15, 2013 at 10:05 pm |
  3. Virginia

    so the equation should be 3+=4 calculating before 3 then + the calculation of .1 add them all together for the full calculation but the .1 will take the shape of ~3=0infinity and 4 will take the shape of 0 to infinity more thinking need to be done to come up with the right equation here...it seems to me that 3+=4 is larger then 3 as it stand in 3.14 to form the loop of pi...

    March 15, 2013 at 9:56 pm |
  4. Virginia

    the universe does not look like an egg the discrepancy of .14 multiply changes the object shape its a large miscalculation and it noticeble by the shape measurement outcome...the arror is smaller then the object measure but large enought to disfigure the object shape on two sides the represented object oposite poles...cause the 4 ends up representing the left side of the object with it errors and the .1 end up representing he right side of the object...but the error is minimal and can only effect the shape when it's a very large object like the inverse's perimeters...infinity is large enought to create the ellusion by the error that the universe is shaped as an egg...

    March 15, 2013 at 9:51 pm |
  5. Virginia

    `3=0infinity3.1=3.14 the 4 is larger then .1 in this case cause infinity...this depending on point of reference... if 3 represent a large abject or small object or earth size objects...3 represent all 3 of them accurately .14 is where the discrepancy is...

    March 15, 2013 at 9:44 pm |
  6. Virginia

    its like the 4 on pi represent the 3333333333333333333333333 into infinity but its not 4 its less then 4 it's one third of a demantion...represented by 4 a 3+ it's not larger then .1 and its not larger then 5 to make the .1a 2 it's different dimention so it cannat be a 3 so the .1 stays as it is for luck of a better representation of such unite...

    see 33333333333 into infinity is one demantion of a whole three parts of 3333333333333 into infinity represent a whole of the universe so 333333333333 into infinity + 33333333333 into infinity + 333333333333 into infinity is one universe...so the first 33333333333 into infinity represent the larger object or in this cause as in pi represent the second demantion 3 the .1 represents the smaller demantions as particle and the 4 = 3+ represent the larger like planets and space demantions...all representing one the whole universe in all it's sizes...this being he most important reason why .14 need to be figure out to be the most accurate which at this time it's not yet but it's workable cause its the closed to perfection we've come to so far in our knowlege of math...so math need to discover how to incorporate the other two demantion of size into math the larger and maller and earth's size object...infinity its not an earth like object its consider large size. particle aren't eath like object they are consider small size 3 in pi represent the earth like object that's why ti works .1 represent the small particle size objects and the 3+ represent infinity large size object...

    March 15, 2013 at 9:35 pm |
  7. Virginia

    i still think the inacuracy of pi is with .14 - 3 is correct 3+3+3=9 the problem beggins when .14 attempt to complete the other one missing in the equation to make whole one-1~infinity or 0-1-10-100-1000 and so on...0000000000000 like in computing...when the number is infinity is '0' infinity within zero...so .1 stand for second demantion, and 3+ =4 = "0" infinity so it might be discribed as ~ 0 = infinity's third demantion...right before -0 negative zero not the same as ~0 infinity so one third of ~0 infinity is inacurately represented by the 4 meaning 3+ actually a ~0 infinity value in a third demantion of math... the .14 dismisses about 40% of accuracy in the particle levels or on the large planet levels but isn't noticeble on the measurement of earth shaped objects the discrepancy isn't noticeble...how to create a more accurate pi??? with this knowledge???

    March 15, 2013 at 9:22 pm |
  8. Virginia

    i don't believe that the universe is shaped like an egg- this shape come due to the error misscalculation of 3.14 when this error is large or small its notible in the shape of the objects....second while its true the universe is expending...or at least it gives that illusion in fact it isn't...but i will agree it is expending but it will never reach the ending there for it isn't expending after all...with out knowing much about portman and his personal life style i was accurate on the prediction of his life style so it doesn't come as a surprise what was reported today about his son...accurate equation –pi predictions can too predict the lifetyle of individuals too...i won't say nothing more then what he is willing to admit too though...

    March 15, 2013 at 12:53 am |
  9. Virginia

    pi= 3.14 = 3.1~4 = 3.3~3 - where three demantion interact with one unother as one not just the circle viewed from one demation but a circle viewed in all 3 dimentions in its intire formation from with in and with out...three separate infinites of there is infinity with in zero to one, there is infinity withing each one to two and so on...first reality 3 second reality .4 third reality ~4 or it could be called demations as well, or just noticing that withing zery there is infinity, as well as there is infinity between one and two...

    March 15, 2013 at 12:46 am |
  10. Virginia

    ok, let me say it again... 3 is one third of 99999999999999999999999999999 first universer or demantion .1 is only attempting to represent a third of the second demantion .99999999999999999into the second universe or demantion of infinity and though there is no symbol representin what the 4 is locatede in the third demantion 4 is "unknown symbol of a third demention representing 3+ one third of that third demantion - made up symbol ~9999999999999999 into infinate third universe o demantion...the fourth and fith are so small but can all be calculated intoo the made up new symbols representing this dimantion by using the same mathematical equations... disregarding the last to dimantions mention before - so make three separate calculations add them up then you have the most accurate pi equation known to menkind as of today...with this formula you can predict the future million of years and have an most accurate tail of the past just by knowing what is going on in the present time...the first universe if reality as we see it 999999999 the second is the secuences of infinite posibilities .999999 and the third is the yet unexplore in any fashion as of today it luck a symbol or description as the rest of the other demantions within reality as we know it...~99999999

    keep in mind that every time we talk about pi we are only using one third of 99999999 .99999~999999 3.14 first nine with our a piriate represent 3 second 9 after the decimal represents the .1 and the new symbol ~4 represented by ~9 in any demation...this being why pi equations works ....but are not 100% accurate...but will be if you follow my intructions...

    March 14, 2013 at 11:04 pm |
  11. PIfan

    "Be forewarned: We're going to have to use a bit of math...". Ugh! PLEASE don't write like that! It's pathetic, especially since you don't proceed to use much math at all! Would you even consider writing "Be forewarned: We're going to have to use the word "the" multiple times in this article"? In an article about gardening, would you apologize for using botanical jargon? Most likely not. You might as well apologize for opening the door to a fantastic art gallery.

    March 16, 2012 at 7:17 pm |
  12. dosaxes

    Math isn't scary, but our tax dollars spent on crickets walking on hampster balls kinda is.

    March 16, 2012 at 4:20 am |
  13. navyvet8192

    Pi = r squared

    Cornbread r round!

    March 15, 2012 at 12:48 am |
  14. PaSeti

    DERP FLOW;
    Was your Pi baked by a crusty mathmagician?
    Pi is peachy, there are lots of pigs in Georgia= +P, which gives us PiG.
    PiGs give us bacon.
    Bacon is good.
    Math is then a route to bacon.
    Math is good.
    Porkpie is not a food nor is it a calculation.
    Porkpie is a hat.
    People wearing porkpie hats know a lot about pigs.
    Not so much about math.
    Math is elitist.
    OFF THE MATH!
    ...tin soldiers and nixon comin...
    4 dead in ohio<===((( See? MATH!
    preoccupy an occupier today, or tomorrow if you were preoccupied.

    March 14, 2012 at 10:10 pm |
  15. PaSeti

    PPPppHHHhhhTTTttt.......Logical sets...LULZ....thithies.

    March 14, 2012 at 9:59 pm |
  16. Dr. Fink

    Pi is exactly 3!

    March 14, 2012 at 9:27 pm |
  17. Craig

    It's kind of sad that they have to include a patronizing warning that this article contains math.

    March 14, 2012 at 9:14 pm |
  18. wavejump1100

    i find it amazing that someone actually memorized pi out to 67k digits. i have trouble remembering phone numbers.

    March 14, 2012 at 7:52 pm |
  19. Leucadia Bob

    [youtube=http://www.youtube.com/watch?v=sIu5aPIIzzM&w=640&h=390]

    March 14, 2012 at 6:37 pm |
  20. dh

    interesting in the 10,000 numbers that cnn posts on this article, about 800 digits from start is
    the series 999999 , no other series comes close to this many same digits in a row; for example maybe one at 8888,
    while three in a row like 333 111 is more common, a series of 6 same digits in a row like 999999 is very rare
    in at least the first 10,000 digits.

    March 14, 2012 at 6:24 pm |
    • Jim

      actually, we have no way of knowing how rare any specific string of digits is in a number that is, as far as we know, infinitely long.

      March 15, 2012 at 2:09 am |
  21. Caihlyn

    Why does an article that intelligently explains the relevance of pi, have to start with a disclaimer: "Be forewarned: We're going to have to use a bit of math to explain why. Yes, math formulas may seem scary, but trust us: It's worth the challenge."?

    Why presume that most Americans reading this article would be troubled by its mathemcatical content?

    March 14, 2012 at 6:21 pm |
    • David

      The disclaimer is necessary because unfortunately, there are many people that WOULD be troubled by the mathematical content. They prefer to stick their head in the sand and remain ignorant. :(

      March 14, 2012 at 7:19 pm |
    • Fearfighter17

      That would be for people like me! It's amazing what I have forgotten about pi being out of school for so long! This is a great refresher...now I wish I could understand the math in Walter Isaacson bio on Einstein...that guy was not from this planet!

      March 14, 2012 at 8:50 pm |
  22. mysteriouspi

    Pi has definitely been important in my life. It is quite easily my favorite number, though two comes close.
    Though I must point out, eating pie is somewhat irrelevant on Pi Day. Do consider that pie=pi*e, which is 8.53973... Too bad there isn't a fifty-third of August!

    March 14, 2012 at 6:19 pm |
  23. Chris, Austin

    What a piece of work is a man, How noble in
    Reason, how infinite in faculties, in form and moving
    how express and admirable, In action how like an Angel!
    in apprehension how like a god, the beauty of the
    world, the paragon of animals.

    March 14, 2012 at 6:11 pm |
    • svscnn

      gotta love the dichotomy between this post and the one directly below it.

      March 14, 2012 at 6:17 pm |
    • Moo

      We're not the paragon of animals. I'd like to see you outrun a cheetah.

      March 14, 2012 at 6:24 pm |
      • Chris, Austin

        That's why we built cars, and airplanes.

        And spacecraft. Voyager is traveling at @ 32,800 MPH.

        Once in awhile, it is a good thing to appreciate that we, as a species, are capable of great and noble feats.

        March 14, 2012 at 6:32 pm |
  24. god

    PI in DA FACE!!!!!

    March 14, 2012 at 5:57 pm |
  25. Alex

    That's the most disgusting looking pie I have ever seen.

    March 14, 2012 at 5:44 pm |
    • SB

      The adornments do look a bit like uncooked meat. Pink was probably not the best choice of coloring.

      March 14, 2012 at 5:49 pm |
  26. Robert

    Write 3.14 on a piece of paper and then, either hold it up to a mirror, or hold the piece of paper up to a light and look through the reverse side for a surprise!

    March 14, 2012 at 5:23 pm |
    • svscnn

      A ha! Thus proving that Pi = Pie (sort of), thus proving that Pi is, in fact, edible in an alternate universe!

      March 14, 2012 at 5:59 pm |
    • Office Junkie

      that was cool, i did not see that coming, that was PI-larious

      March 14, 2012 at 7:12 pm |
  27. NickZadick

    Why do Americans write the date wrong? it's rather obvious it should be from smallest to biggest so 14/03/12!! using month then day then year is silly!!

    March 14, 2012 at 4:55 pm |
    • svscnn

      Hmmm... seems like "120314" would be preferable for sorting purposes.

      March 14, 2012 at 4:58 pm |
      • Woodzilla007

        svscnn wins this debate! Putting the day first is just plain silly!

        svscnn "Hmmm... seems like "120314" would be preferable for sorting purposes." March 14, 2012 at 4:58 pm

        March 14, 2012 at 6:52 pm |
    • Harvry Wallbanger

      It would be un-American to do anything right or logical. Things like switching over to the metric system and to stop fighting senseless wars ... Maybe someday ...

      March 14, 2012 at 5:10 pm |
      • SB

        Hey, if it's good enough for Burma and Liberia it's good enough for the US of A! Seriously, those are the only three nations that haven't adopted SI measurements.

        March 14, 2012 at 5:34 pm |
      • Joe

        Hey, if you guys don't like the American way I suggest you gtfo and go read some BBC... we really got no problem with anyone not like it, haha we could care less

        March 14, 2012 at 5:40 pm |
      • SB

        Joe, I counter by suggesting that you enroll in a remedial English class, so that the next time you're tempted to participate in a discussion your post might actually make sense.

        March 14, 2012 at 5:44 pm |
      • NickZadick

        Wellll... to be honest .... in Quebec people use the english system for some things... height ( I am 6' 1") no idea what it is in metric...almost everybody states their height in feet, also people say their weight in pounds..... also, building and construction elements... all inches and feet.. it is even displayed like that at hardware stores (with metric in small print)..everything else is in metric...except at the butcher's with half of the people in grams and the rest with 1/4 pound etc.... how's that for logic? ;) :D

        March 14, 2012 at 5:54 pm |
      • David

        It's like that near Toronto too. We use some weird hybrid metric/imperial system, depending on the measurement in question. I couldn't tell you my height in centimeters or my weight in kilograms, but I do temperature in Celsius and distance in kilometers and couldn't begin to tell you the imperial equivalent.

        March 14, 2012 at 7:23 pm |
    • Lila

      Personally I prefer month first, it's more important than the day. The day can belong to any month vs there is only one number representing the month so it's faster to look at it.

      March 14, 2012 at 6:10 pm |
    • Species 8472

      If we did that today would be othewrwise irrelevant and you would have had to find something else do.

      March 14, 2012 at 8:15 pm |
    • TAK

      Ok Nick, I'll bite. Your system does indeed make sense from a numerical point of view. It progresses from day to month to year. Perfectly logical. But in colloquial English we say "March 14" not "14 March". So our date is written to match our way of speaking. Also logical.

      March 15, 2012 at 12:05 am |
  28. Jon

    Every time I read these lightyears things, I think it's going to be good this time....but it just makes me feel 300x dumber. I feel like I'm reading a report from a know it all 1st grader. "Math is really scary to you, but can be fun. 4/3 pi*r^3 is a complicated formula and it uses math – I know you have no idea what that means, but believe me I'm smart and I know it's really cool."

    And really, on the crickets? They could have just as easily put anything else. Of course things are sometimes at angles to other things, and those angles can be expressed in terms of radians and they'll be between 0 and 2pi because that's how radians work! aaaaghhh!

    March 14, 2012 at 4:53 pm |
    • Ashrakay

      100% agree. These articles are especially juvenile when compared with BBC's reporting. They actually have a "Science" section. You get the same kind of experience when you compare a show like BBC's Wonders of the Universe to any show on Discovery.

      On BBC they may ask, "What is the evidence for life on other planets?" While on discovery they ask, "Can we survive an alien invasion?"

      March 14, 2012 at 5:23 pm |
      • John

        It's the Yanks! On old morse code! They are planning a countattack! They claim they can bring down the shields! It's about time... What time do they want to begin?

        March 14, 2012 at 6:58 pm |
  29. Chris

    Based on the comments I see here, the folks who discovered pi thousands of years ago (and only very roughly determined its correct value) are far more intelligent than the average internet surfer. Public school much? Perhaps if you think I'm referring to YOU, you should politely excuse yourself from any further intellectual activities, go back to school, and do something you've never done before - pay attention.

    March 14, 2012 at 4:31 pm |
    • svscnn

      Regardless of who it is you're addressing, Chris, your condescending posts don't make you appear any smarter.

      They do, however, make it obvious that you'd probably be a lot more comfortable if you'd only remove that stick.

      March 14, 2012 at 4:56 pm |
    • Chris's Mom

      Son, try to get out more and play. Really.

      March 14, 2012 at 5:25 pm |
    • American Idiots

      I agree with you Chris... The lack of American intellect is beyond embarrassing and it's sad to say, but the end is in sight. We have become a culture of lazy, self-involved, TV driven morons. I wonder if this is what happened to the Romans (minus the TV, of course...) I have a small Facebook account and have seen over 50 posts of people asking, “What is PI?” Most are college educated individuals that tried looking it up in Google but still couldn't piece it together... A sad era for the US indeed.....

      March 14, 2012 at 6:33 pm |
  30. Chris

    If you think this article is underwhelming, try explaining to the average dolt how pi is related to the natural logarithmic base, e. I have a degree in math, and I barely understand that one myself. But it is beautiful, and anyone who can't comprehend it can be somewhat forgiven for falling for religious dogma.

    March 14, 2012 at 4:12 pm |
    • Dr. Wheeler

      The relationship to which you refer is the relationship of the fundamental constants which is expressed in following equation:
      The base of the natural log "e" (2.7182818284...) raised to the power of ( "i" (imaginary number derived from the square root of -1) times "Pi" (3.1415926535...)) plus one equals zero.

      March 14, 2012 at 5:06 pm |
      • Dr. Nick

        Hello Everybody! I was just about to type the same thing!

        March 14, 2012 at 6:38 pm |
    • Rich

      Wow, full of yourself much? I am highly religious and also a mathematician. I understand what you are talking about. I believe God to be the master mathematician as well. Just because one is knowledgeable in science or math doesn't make them not religious. On the contrary science and math help back up my belief in God.

      March 14, 2012 at 6:42 pm |
  31. Marivs

    See Exodus 3:14

    March 14, 2012 at 4:12 pm |
    • Observer

      Better still, see: I Kings 7:23

      It makes calculations much easier by showing that pi is equal to 3.0

      March 14, 2012 at 4:33 pm |
      • Marivs

        See 1 King 7:26 (about the shape). This could mean that 1 King 7:23 was talking of 30 cubits at a lower diameter.

        March 14, 2012 at 6:03 pm |
      • Observer

        Marivs,
        That's just another failure to try to explain the errors and contradictions in the Bible.

        Here's what it says:

        I Kings 7:23 “And he made the Sea of cast bronze, ten cubits from one brim to the other; it was completely round. Its height was five cubits, and a line of thirty cubits measured its circ-umference.”

        March 14, 2012 at 6:46 pm |
      • Marivs

        You better see what the shape was. You sound dogmatic.
        It says :... and it took a line of 30 cubits to circle all around it." Now 1 Kings 7:26 gives us additional information that could explain the lenght of the line. If you want to ignore that FACT it's up to you. Science is based on facts not prejudice. Take all the facts into consideration.

        March 14, 2012 at 8:59 pm |
      • Observer

        Marivs,

        Science is based on FACTS. A circle with a diameter of 10 CANNOT have a circ-umference of 30. Maybe you should review the definitions of circle, diameter, and circ-umference.

        March 14, 2012 at 9:27 pm |
      • King James

        It's just rounded isn't it? No matter what number you use, since Pi is a transcendental number, it will be rounded to some degree. They were talking of 5, 10, and 30. Seems not very exact to me; "5, 10, and 30 cubits, more or less."

        March 14, 2012 at 10:49 pm |
      • Marivs

        Could you please give me the exact length of the line? Is it 31.4?

        March 14, 2012 at 10:51 pm |
    • Chris

      Why? Because it's chapter 3, verse 14? Oh, how clever!

      March 14, 2012 at 4:34 pm |
      • Marivs

        Chris, do yourself a favor, think before writing.

        March 14, 2012 at 4:56 pm |
    • Robert

      Beautiful!

      March 14, 2012 at 5:25 pm |
    • Moo

      No thanks. I prefer reality over silly mythology.

      March 14, 2012 at 6:21 pm |
  32. blaqb0x

    More articles on how science is really used, please....

    March 14, 2012 at 3:58 pm |
    • Chris

      What are you, Amish?

      March 14, 2012 at 4:15 pm |
  33. svscnn

    On an unrelated note, there are currently only 68 (well, now make that 69) comments on this article.

    Meanwhile, there's probably another article on some Kardashian (sp?) somewhere with over 3k comments and counting.

    Wish that was funny.

    March 14, 2012 at 3:54 pm |
  34. GoRemote

    Having lost a couple fingers in a tragic beaver accident, for me Pi is 3.11037552421026.........

    March 14, 2012 at 3:53 pm |
    • Scott

      You had me at "tragic beaver accident"

      March 14, 2012 at 4:23 pm |
  35. svscnn

    Nothing like a big 'ol endless slice a Pi to get the philosophy thoughts a churnin'.

    Yep, ya gotta love Pi.

    March 14, 2012 at 3:48 pm |
  36. 314th entry

    So like we could be totally cool and stop posting here after 314 entries. not.

    March 14, 2012 at 3:26 pm |
    • Caveman

      I think that the value of pi is an indescrepency, a flaw, that the universe can't account for, and that's why it is also based with the number 3, in relation to the pyth. theorum if triangles. The point is.. pie goes on forever because it's a flaw that even the creator of the universe can't account for.

      March 14, 2012 at 3:36 pm |
      • clearfog

        So easy as pi, even a caveman . . .

        March 14, 2012 at 3:41 pm |
      • Chris

        What the @#$%^ is an "indescrepency", Einstein?

        March 14, 2012 at 4:20 pm |
      • glennrobert

        So you think Pi is a problem? Look up the fraction 1/137 on google.

        March 14, 2012 at 4:53 pm |
      • god

        an indecent discrepancy......

        March 14, 2012 at 5:26 pm |
  37. svscnn

    I like pie as much as the next guy, but this whole article and comments section is really confusing. For starters, why is everyone mis-spelling "pie"?

    Is this some kind of joke that I'm just not getting?

    March 14, 2012 at 3:21 pm |
    • Observer

      Are you a Republican and a fan of George W. Bush?

      March 14, 2012 at 3:27 pm |
      • svscnn

        Ahh... yeah... it was a joke. I would hope that someone flouting the name "Observer" might be observant enough to get that.

        Oh, the irony.

        March 14, 2012 at 3:40 pm |
      • Observer

        My response was a joke too that you apparently didn't get.

        March 14, 2012 at 3:51 pm |
      • svscnn

        Oh... my bad.

        Guess I ain't exactly the sharpest knife in the drawer either. ;)

        March 14, 2012 at 3:56 pm |
      • glennrobert

        You are heartless!

        March 14, 2012 at 4:55 pm |
    • clearfog

      I was wondering how politics was going to get into this. Shut your pi hole.

      March 14, 2012 at 3:37 pm |
      • svscnn

        "shut your pi hole."

        Priceless. If only there was a "like" button.

        March 14, 2012 at 3:42 pm |
    • yasmin

      its not mis-spelled "pie" is the food, "pi" is the mathematical term

      March 14, 2012 at 3:55 pm |
      • svscnn

        Oh... well.. NOW it makes sense.

        March 14, 2012 at 4:00 pm |
      • svscnn

        (sigh)

        March 14, 2012 at 4:00 pm |
    • Observer

      svscnn,

      I wouldn't say that. I think your comment on the Kardashians (however they spell it; I would have checked that myself if it had been worth the effort) was right on!

      March 14, 2012 at 4:02 pm |
      • svscnn

        Yeah, I wasn't about to spend any extra seconds of my life spell-checking that either, Observer.

        You can never get 'em back, ya know? ;)

        March 14, 2012 at 4:06 pm |
      • Observer

        svscnn,

        Amen.

        Thank you for the apology, but didn't you get the memo? Bloggers are NEVER supposed to apologize or admit they are wrong. Instead, if questions are raised to show they are wrong, they are to resort to any of the 3 approved responses: (1) ignor the question, (2) attack their opponents with juvenile insults or (3) pretend they didn't see the response and leave.

        March 14, 2012 at 4:19 pm |
      • svscnn

        Hmmm.... I'll have to keep that in mind for the future.

        March 14, 2012 at 4:31 pm |
  38. W247

    I Love Pi day!!! It's the happiest day of my life! (Happy Bday to me!)

    March 14, 2012 at 3:15 pm |
  39. willy

    Mmmmmmm Pi!

    March 14, 2012 at 3:13 pm |
  40. mecatfish

    shaved pi.

    March 14, 2012 at 3:08 pm |
  41. JSC

    "measured as angles ranging between zero and 2pi radians"

    Crickets? Really? They are measuring an angle. They happen to use radians (which is based on pi). Pi is not related to crickets.

    That's like bringing up CNN.com on a discussion about the color blue, because blue is sometimes used on CNN.com. Sure, that is true, but it is completely irrelevant.

    March 14, 2012 at 2:21 pm |
    • OneAlbert

      Quite right! I just posted the same thing at 2:21 also, a few comments below.

      March 14, 2012 at 2:23 pm |
    • engineer long time

      Cricket pi mmmmmmm mmmmmmm good

      March 14, 2012 at 4:12 pm |
  42. OneAlbert

    If you're into the digits of pi, check out this book:

    http://cadaeic.net/notawake.htm

    March 14, 2012 at 2:15 pm |
  43. Claudio

    "We measure the discrepancy between the direction of the loudspeaker and the direction in which the cricket walks, both of which are measured as angles ranging between zero and 2pi radians,"
    Isn't 2pi rad = 360deg? so 2pi rad = 0deg? so basically he meant angles ranging from 0 to 360deg, which is a full circle. Where am I wrong?

    March 14, 2012 at 2:14 pm |
    • OneAlbert

      I don't see that you're wrong anywhere. He's saying that they measure the angle, and indeed angles range from 0 to 2pi radians (or 0 to 360 degrees). Nothing wrong there either, but the whole cricket example is rather specious – it's basically saying "in this experiment we measure angles, and angles are involved with pi".

      March 14, 2012 at 2:21 pm |
      • Claudio

        well, if we are talking about how crickets walk respect to a speaker and their walk direction is basically any direction there is really no relationship with pi.

        March 14, 2012 at 2:28 pm |
  44. SPACE ORBIT 1965

    I LOVE THIS CNN

    March 14, 2012 at 2:08 pm |
  45. jim atmad

    Pi is good
    Pi is fine
    Three point one four one five nine

    Happy Pi Day!

    March 14, 2012 at 2:02 pm |
  46. ProudTexan

    πR2 (Pi R square)... No, pi are not square. Pi are round. Cornbread are square! :-)

    March 14, 2012 at 2:01 pm |
  47. freeme10

    I find it fascinating that our scientists can find universal truths by using numbers, which were thought up by man thousands of years ago.

    March 14, 2012 at 1:49 pm |
  48. shawn

    I believe in I.D.therefor pi doesn't exsist!

    March 14, 2012 at 1:48 pm |
  49. Easley Blackwood

    A surprisingly close approximation is the fourth root of 2143/22.

    March 14, 2012 at 1:38 pm |
    • awtpSIM

      Heh – cool!

      March 14, 2012 at 3:45 pm |
  50. Ed

    Other fun fact: Pi Day is the day that MIT admission acceptances are announced (3/14), at time Tau (2 pi, or 6:28 pm)

    March 14, 2012 at 1:30 pm |
  51. SantaPi

    'Twas the night before Pi Day and all was quite grand
    A series of numbers were sent to the land
    An obvious ploy to please nerds in the world
    For math teachers to punish the boys and the girls
    Old Santa Pi drops down the chimney chute
    To wreck and to pillage, to steal and to loot
    For Santa Pi knows he has nothing but time
    While you figure out what comes after 3.14159

    March 14, 2012 at 1:07 pm |
  52. J-L

    Pi also happens to be the approximate value of the square root of ten.

    March 14, 2012 at 1:00 pm |
    • TAK

      I wouldn't want any engineers using an approximation that rough.

      March 14, 2012 at 1:06 pm |
      • blaqb0x

        Typically, getting 85-90% accuracy is enough for everyday applications.

        March 14, 2012 at 3:55 pm |
    • jim

      Not even close!

      March 14, 2012 at 4:09 pm |
    • Chris

      So what? The entire modern, tempered musical pitch structure is based on an exponential function that approximates the fractions of Pythagorean harmonics. The connection between 10^1/2 and pi is practically meaningless compared to that. A little knowledge is a dangerous thing, folks.

      March 14, 2012 at 4:41 pm |
  53. FactsRBad

    Well, I hope it is clear to all of you from this article that there was some really "intelligent designing" going on when Pi was formulated. If not how can one explain PIEty or the offensive hipPIEs that dog our every day lives. in protests around the country Frankly, I find all of the Pi references pretty crepPIE and intend to sign off from this blog and make whopPIE with my yupPIE wife. I would sign this with my sharPIE if I could – I too am thankful for smart people – Hail to science!!!!!!!!!!!!!!!

    March 14, 2012 at 12:53 pm |
  54. T.A. Martin

    Isn't Pi day in three years?

    3.14 15 :)

    March 14, 2012 at 12:51 pm |
    • elandau

      I'm sure there will be an even bigger celebration then! Thanks for reading.

      Elizabeth Landau, CNN

      March 14, 2012 at 1:04 pm |
    • George

      Actually, since the value of Pi is 3.141592653 . . ., rounding to the nearest 1/10000, gives a value of 3.1416. Let's not celebrate too early.

      March 14, 2012 at 3:09 pm |
  55. Revenge of the Nerds

    Ahhh, Hair Pi...

    March 14, 2012 at 12:49 pm |
  56. Jessy

    Looks at the 10,000-digit value of Pi provided by CNN.
    Tries to read the numbers from start to finish.
    Stops after the first 10 digits.
    Looks at CNN and flips the angry bird.

    March 14, 2012 at 12:42 pm |
  57. avelaine

    Reblogged this on Peculiar As Envy and commented:
    Happy Pi Day! I am making a pi pie today to celebrate.

    March 14, 2012 at 12:29 pm |
  58. alvin

    http://www.trendingcore.com/pi-day-2012/

    March 14, 2012 at 11:57 am |
  59. Kyle

    "Yes, math formulas may seem scary, but trust us: It's worth the challenge."

    The challenge? The most complicated formula in here aside from Einstein's is 6/pi^2. If you can't understand that one, you shouldn't have been allowed to graduate middle school.

    March 14, 2012 at 11:46 am |
  60. Alex Vincent

    Ah, pi. π for us web developers (courtesy of http://www.fileformat.info/info/unicode/char/03c0/index.htm)

    March 14, 2012 at 11:38 am |
  61. EJB

    that pie looks like it is made of human flesh. mmmmmmmmmmmmmmmmmm flesh pie arghglglglglglglgglgl.....

    March 14, 2012 at 11:00 am |
    • JLC

      Get Help !!

      March 14, 2012 at 12:40 pm |
  62. JohnnyDH

    I have Pi memorized to 7 decimal places. Not as impressive as some. However, I can recite the alphabet backwards and sing the McDonalds menu song. So there!

    March 14, 2012 at 10:54 am |
    • Jedi Clampet

      I can say The Lords Prayer backwards as I levitate and a curse of frogs melt the stones of the castle.
      I can desecrate a virgin at the same time, and make a gravy and bologna samich, while looking for Whitney's crack pipe and tying a mayfly and casting just beyond that odd shaped stone. As I'm doing my Elvis impersonation and dancing with Dennis Hopper to the sweet, sweet strains of " In Dreams" about Roy Orbison's Candy Colored Clown, as sang by Dean Stockwell. I usually have to stop here and call Wayne Newton to see what's next on the old agenda, pudenda, whatevah. NO Liberace.

      March 15, 2012 at 2:48 am |
  63. CerealByDesign

    Pi Day is meant to be eaten. Check out this breakfast pie.

    http://cerealbydesign.blogspot.com/2012/03/pi-day-pie.html

    March 14, 2012 at 10:50 am |
    • Yankees27X

      Are those chocolate frosted mini wheats on top of the pie?

      March 14, 2012 at 8:16 pm |
      • CerealByDesign

        Yes, you are correct.

        March 14, 2012 at 10:40 pm |
  64. D.S.

    As that great unsung genius Mrs. Einstein used to say, "Pi equals fat behind."

    March 14, 2012 at 10:36 am |
  65. Drowlord

    I memorized Pi to 100 digits when I was 12. At 38, I can't say that it's been especially useful for math or engineering, but it has amazed and amused friends and family on many occasions. My kids frequently ask me to recite pi. I can say it really fast; it takes just a few seconds.

    March 14, 2012 at 9:52 am |
    • TAK

      Well, the thing about that is, once you get past five or six digits the odds are that no one else in the room will know if you've made a mistake so you can just make it up as you go.

      March 14, 2012 at 12:50 pm |
  66. Katie

    I have never had to use pi.....

    March 14, 2012 at 9:48 am |
    • Shadynuk

      What about pie? Ever used that?

      March 14, 2012 at 12:48 pm |
  67. EJB

    The whole concept of irrational numbers is yet another one of Satan's deceptions. Like dinosaur bones, extended warranties, and soy milk.

    March 14, 2012 at 9:42 am |
    • Starman

      It's so difficult to find anything to really believe in anymore.

      March 14, 2012 at 9:44 am |
    • Calico

      This comment made my day.

      March 14, 2012 at 1:52 pm |
    • Nick Fortis

      Dude: It is even MORE diabolical than that. Pi is–horrors!–Transcendental!

      March 14, 2012 at 3:24 pm |
    • Chris

      Enterprise Java Beans?

      March 14, 2012 at 4:58 pm |
    • Yankees27X

      Satan just has to bring on those unnecessary things...like when you find a jolly rancher wrapped in a blue rasberry wrapper when its watermelon and your roomate wants to post it on facebook...uh idiots.

      March 14, 2012 at 8:20 pm |
  68. Starman

    Let's get started. Did god create Pi and the Fibonacci sequence, or was it man?

    March 14, 2012 at 9:34 am |
    • EJB

      meh. such things will still exist long after our sorry species is extinct, and with us, our gods.

      March 14, 2012 at 10:59 am |
    • tcp

      Flawed question. To answer is to acknowledge that there is a god...and if you acknowledge that there is a god, there is only one answer...

      March 14, 2012 at 11:43 am |
    • TAK

      I have a better question. Can your god create a universe in which the value of pi is different? The answer is no. Doesn't seem that all powerful now, does he? Think about it. Physical constants (the gravitational constant, speed of light, etc) can be different in other universes. But the value of pi must always be the same.

      March 14, 2012 at 1:00 pm |
      • Sean D

        Maybe that is BECAUSE my God (with a CAPITAL "G") discovered PI which is why it is used and universally cannot be changed... Just like Him. Yes.. Him. Not her or it. Him. : )
        At least making this a religious vs. science discussion makes it more interesting.

        March 14, 2012 at 5:09 pm |
    • TAK

      And I'll bet he can't divide by zero either...

      March 14, 2012 at 1:02 pm |
      • basketcase

        or take the square root of -1

        March 14, 2012 at 1:24 pm |
      • TAK

        No, he'd be pretty good at taking the square root of -1... Being imaginary and all...

        March 14, 2012 at 1:38 pm |
      • Q Daniels

        Hmmm, dividing by "0" is no problem for man or God. Man may have difficulty comprehending the answer, though I'm sure God doesn't. Also, i have no problem calculating the square root of -1. i do it all the time...

        March 14, 2012 at 1:46 pm |
    • Observer

      The Bible gives an example where pi is equal to 3.0.

      Ooops.

      March 14, 2012 at 2:28 pm |
      • Chris

        Yet another indication that it was written by a being somewhat lacking in the omniscience department.

        March 14, 2012 at 5:00 pm |
      • Yankees27X

        You realize when you round the first 4 digits of pi, 3.14, it makes 3.0.

        March 14, 2012 at 8:22 pm |
    • Sean D

      Here is a little deeper question... Q. If man became capable of understanding all science and by doing so was able to control it what would that make that man? A. A god.
      Science and God... God and Science... You can't have one without the other. Without God science is flawed and without science God would be flawed. The only place they don't coexist is in closed minds that feel they have to be smart enough to figure it out by logic. Science isn't discovered only by logic. A lot of times it's by luck or... divine inspiration. Got to give credit where credit is due.

      March 14, 2012 at 5:15 pm |
  69. Starman

    I personally am thankful for the smart people.

    March 14, 2012 at 9:31 am |
    • TheMovieFan

      You're welcome.

      March 14, 2012 at 10:56 am |
      • James

        Darn, I was really hoping you would use "your." I've been searching for irony all day.

        March 14, 2012 at 12:52 pm |
      • glennrobert

        Modest! Meanwhile what about 1/137?

        March 14, 2012 at 5:07 pm |

Contributors

  • Elizabeth LandauElizabeth Landau
    Writer/Producer
  • Sophia DengoSophia Dengo
    Senior Designer