Pi Land by Eve    Fun Activities: The Pi Trivia Game Pi Trainer: test your memory    Aesthetics: Poetry Photos Art Quotes    Nerd Stuff: Digits of Pi! Frequency of Each Digit of Pi Calculation of Pi (Gregory-Leibniz Series) Calculation of Pi (Monte Carlo Method) Reviews of Pi Books   Source: xkcd Eve Andersson (eve@eveandersson.com)

Great Pi Day Gift! Los Boludos Made with original vintage vacuum tubes!

Comments

Pi page

Just to say it's wonderful to find the Pi Page still going - as a young(ish) graduate in the early 1990s, the site probably did more than anything else to convince me that Mosaic (ask your grandparents) was useful for something other than downloading porn and spreading maliciously doctored photos worldwide. If there's ever an Internet Lifetime Achievement Award, I'll happily nominate Eve...

And another thing - how come nowhere on this page can I find my favourite property of pi, our old friend e^(i*pi)-1?

And another thing (part 2) - I just want to point out that I got 13/25 on the Pi Test - and am a qualified mathematician (who admittedly graduated 13 years ago but even so!)

And (one last) thing - if the page needs a pompous slogan it should really be "One measures a circle beginning anywhere" (motto of the Fortean Society and all its spin-offs) - it may be meaningless but it sounds very impressive. Which in itself kinda sums up most mathematics.

-- Aidan Merritt

Updates

Your Pi memorization and calculation records aren't up to date. I knew which records you were talking about, but I think that you should add the fact that 1.2411 trillion digits of pi have been calculated and that the Japanese guy has now memorized 60,000. Other than this you're site is great and I love the trivia game, thx.

-- Spencer Shepard

You're Back!

Eve! It's more Pi pages! I can't believe it. You should see me jumping up and down like a giddy school girl. Actually, you shouldn't. It's embarrassing.

It?s a shame you didn?t go to Iceland a bit later. I have a trip panned there and Amsterdam for the end of March. Your pictures reminded me of that interesting museum there I heard about a long time ago. Now I need to add that to my itinerary for sure.

Keep up the good work, and it?s good to see you back.

- Your biggest fan (and the guy with a perpetual crush)

-- Van Goodwin

feedback from Sergey

I never had time before but today I seached the PI land and had a lot of fun. Amazing collection of facts, quotes and interesting observations. Feels like I am a student again, so good to learn something new. Thanks, Eve. Your fan = Sergey

-- Sergey Kravchenko

Amazing equation #221

Some people know pi to trillions of decimal places.. actually they don't but that's beside the point. Well anyway I know twentyseven to as many decimal places as you want. I calculated it to 27 million numbers.

My favourite numbers are 27,42,69,pi, and e. Nicely, they fit together like this:

3*arcsin(27^(42/69)/(pi*e))-pi=0.02769,,

Known as the manifesto constant by me

Aamazing!

I really need a hobby, like fish or something..

-- Lee Houghton

your manfest numbers

I understand why you like pi, e, 69, and 42, which is the answer to life, the universe, and everything, but why did you pick 27 as one of your favorite numbers?

-- Spencer Shepard

Eve, you are funny *s*. With the readers ?permission? I will use ?Eves love? and combine it with Lee's favorits numbers to answer Spenser question in a neat (?) way :-)

Could it be so that 27 was chosen because 27=(42-69)e^(pi*i) ? :-)

I don't know how I ended up here but it was a funny site in a nerdy way :-) ... oppps time to work

-- Claes Lanner ... Oslo,Norway

-- Claes Lanner

Integration

Can the integral between 0 and 1, of the square root of (1-x^2) be calculated?

Is this pi/4?

-- Katie Heskins

numbers, and integrals, and stuff

In response to Katie's question about that integral, I can't do it. But the pi quiz says that it is!

Anyway those numbers, the 27 is explained at the 27 discussion forum, http://lbstone.com/27/forum/.. I found that equation in my physics practical exam, it probably explains my bad grade..

At The 27th decimal place in pi is actually the number 27, surrounded by its factors, 3 and 9!

-- Lee Houghton

Sheesh (and help!)

Funny how 69 never seems to need any explanation... Somebody once wrote "I'm a 42(+27) girl!" on my pencil case in high school.

Anyway, in the words of my current mentor (or mental, as had me giggling the other week), "Me just dumb fitter."

As a fitter & turner I work with circles every day, don't need pi too often, but it helps. Tolerances are important, but we mostly deal with radii and how concentric things are anyway, and approximations work.

However, I have often wondered and not bothered to figure out what it would involve: what would be the deal if pi were not pi but some other number (say 1)? Would that do something stupid to all other numbers, or force a weird shape in 3rd or whatever other dimension the result might fit into? How do you invert or generally muck around with something irrational?

Cheers

-- Meaning Fool

Volume of Spheres

Very nice webpage, Eve. I thought I'd mention that a 3 dimensional sphere is a boundary of a 4 dimensional ball and lives in 4 space. Thus the volume of it is not the same as the volume of a 3-ball (equivalently the inside of a 2-sphere) which is 4/3*pi*r^3 (i think :)). By the way, the actual volume of a 3-sphere of unit radius is 4pi^2/2!! = 2pi^2

Best,

Michael

-- M G

Pi²

It's interesting that the volume of a 4-dimensional sphere is (1/2)Pi²r⁴ because Pi² occurs so infrequently in geometric formulas.

One place it does occur is in number theory. Two integers are considered relatively prime if they share no common divisors (other than 1). It turns out that the probability that two positive integers are relatively prime is 6/Pi².

I wonder if there is a geometric interpretation of relatively prime?

-- Eve Andersson

units of volume in 4 dimensions?

The formula for the volume of the 4-d sphere is given above. (Just like when I was taking engineering classes,) I am confused about the units of this calculation. Does inch^4 or (inch^3)(sec) make anymore sense than the 4-d visualization?

I came across this thinking about the tesseract in a movie animation.

TIA.

Regards..

-- Roger Williams

test results

I got 11 out of 25, hs grad, some college. I love reading about math and how our world is shaped by the manipulation of numbers. If you can't prove it with math, it doesn't exist. I read Archimedes Revenge and The Proof. Loved both of them. This is a good site and I'll be reading it often.

-- Sam J. Bowles, III

I need help

I want to know what pi is and what the formula to work it out is. Because I'm trying to work it out to 10 decimal places. and I'm only 12!

-- Fiona Keller

Long time no see

Just scored 22/25 on the pi trivia game, don't know what I did wrong but it sure wasn't the question about who chose the greek letter as the symbol...

Haven't seen you in a while, became infinitely nostalgic while going through some old stuff so I came here to see you. Nice seeing you again =) Would be great to see you IRL again some time too

I'll think of a geometrical interpretation of relatively prime... *hmm* I'll let you know

-- Olle the Greatest

Good

Good website =) - Chris - AmusingDomains.com

-- Chris Sampson

I need help, too

I only know 31 digits of pi, and i need to know 100 at least. I am fourteen and obsessed with pi. any memorizing techniques anyone can recommend? Also, great site, Eve!

-- andreo justiniani

I need to hit the books

I just scored 13/25 on the PI trivia game. I think I need hit the books again and study. But overall nice work you have done on the site, keep up the good work.

- Fubby

-- Mark Gibson

Question

What is the volume of a 3-sphere or the unit radious?

-=Mark=-

-- Mark Ploitian

message to eve

Hello, Eve. I wanted you to know what Pi has meant to me. When I was a nun, living in South Korea, I had never surfed the web, I didn't even know what Internet was (this is the early '90s). Then someone brought a computer to the monastery, and I got on line. He showed me how to "search", and just as a random thing, he typed in PI. Then we picked your site at random, and there was a girl with antennas sticking out of her head, and I read your whole site. I thought, this is amazing. Soon, I was learning all kinds of things. I spent hours on the web, reading and learning day after day. Eventually, I needed to know more, so I went to the UK to do an MA (I'm not a nun anymore). Today I thought of your site for the first time in years, and it's still there! Thank you, Eve. You were my first, and I'll never forget you.

-- doreen chelsea

geometry and coprimality

Some interesting facts on relative primeness here:

• 6/pi^2 "is the fractional number of lattice points visible from the origin" - which is the geometric interpretation of coprimality.
• The probability that n positive integers are coprime is 1/zeta(n), where zeta() is the famous Riemann zeta function. (Here's a proof for n=2.)

So there is an n-dimensional way of picturing whether any n integers a_1, a_2, ..., a_n are coprime - if you have a clear line of sight from the origin (0,0,...,0) to the point (a_1,a_2,...,a_n). And the probability of coprimality is just the probability that there's a clear line of sight to a randomly chosen point with integer coordinates. Naively, you might suppose that each such point has infinitely many points of the form (k.a_1,k.a_2,...,k.a_n) "behind" it - again, as viewed from the origin - and so that there are infinitely many number sets with gcd > 1 for each individual number set with gcd = 1, suggesting that the probability is infinitesimal, i.e. zero. But I suppose we are talking about asymptotic behavior - the fraction of points within a certain distance from the origin which are visible from it, as the distance increases without bound. Evidently it's one of those tricky infinite subsets where the order in which you count things matters...

Anyway, back to pi. This all started with the observation that pi^2 shows up in connection with a 4-dimensional sphere. Could there be some systematic connection between n-spheres and n-coprimality? Before proceeding, let me quote Mathworld again:

Unfortunately, geometers and topologists adopt incompatible conventions for the meaning of "n-sphere," with geometers referring to the number of coordinates in the underlying space... and topologists referring to the dimension of the surface itself... ("Hypersphere")

In other words, for a geometer, a circle is a 2-sphere, but for a topologist, it's a 1-sphere. Up above, Michael Gurvich is using the naming conventions of a topologist; this table of area and volume formulae uses the geometer's convention.

As the "Hypersphere" article describes, the general formula for hyper-surface area is 2.pi^(n/2)/Gamma(n/2), where the gamma function is a generalization of the factorial function n!. Now, as it happens the gamma function also shows up in connection with the zeta function. The zeta function, which is what we need to get at those coprimality probabilities, is fundamentally harder to calculate than the gamma function, even just at integer values. We can calculate Gamma(1/2), Gamma(1), Gamma(3/2),... - i.e. all the gammas we need for the area formula - but for the zeta function, we only have a formula for even integers. zeta(3) has also been studied, but in general the Riemann zeta for odd integers seems to be very poorly understood.

But back to the search for a connection. Is there perhaps some geometric construction, associated with an n-dimensional hypersphere, with which the zeta function can in turn be associated? Well, a start might be made by embedding the n-dimensional lattice of points with integer coordinates, through the inverse of an n-dimensional stereographic projection. The "line of sight" then follows a "great circle" in the (n-1)-dimensional hypersurface. The link would be complete, if the formula for hyper-surface area played a part in the derivation of the formula for fraction of points visible, with the gamma function directly carrying over from one to the other...

-- Mitchell Porter

Message about Pi

Pi is an irrational number. Therefore it cannot be exactly 22/7 because it would then be rational. A rational number is a number that can be written as a ratio of two integers or as a fraction. The ratio of the circumference of a circle to the diameter of the same circle equals pi. Pi is approximately 22/7 and approximately 3.14. For more on the number pi, check out these web pages: http://mathforum.org/dr.math/faq/faq.pi.html http://www.cecm.sfu.ca/pi/pi.html - Eric Sampson

-- Eric Sampson

Digits

I started memorizing Pi about a week and a half ago and I now know 232 decimal places. Going for at least 1k.

-- Scott Wright

Brain Waves

I'm very disappointed that you are no longer telepathically communicating with me.

Or are you...?

-- Barbara Alfors

n-spheres

I want to comment on Mitchell Porter's post above, regarding what exactly is meant by an n-sphere.

There are a couple of difficulties with using "geometer's convention" (see above).

Firstly, if we decide that the dimension of a sphere (or a manifold in general) is to be the dimension of the ambient space that it is embedded in, we quickly run into problems. A circle, for a example, could be embedded in a plane or 3-space or 4-space or even 18 dimensional space. However, having an 18 dimensinal circle is highly unsatisfying. Thus we better be more precise, and define this extrinsic dimension to be the dimension of the *smallest* euclidean space that supports an embedding of our manifold. It is a fact that for a circle this dimension is 2, for a sphere it's 3, and for an n-sphere it is n+1.

It turns out, however, that this kind of dimension could be quite hard to compute. Even for a simple thing such as a circle, a proof that one cannot embed a circle into a line is required. It surely seems obvious from an intuitive standpoint, but mathematically, it is not all that trivial. Things get even harder when one tries to prove the same for a 2-sphere (i'm using a "topologist's convention" here). Can you prove that a 2-sphere cannot be embedded in a plane? It's not easy. Finally, to convince you of non-triviality of this problem, let me ask if a 7-sphere can be embedded in 7-space? I, for one, cannot visualize either a 7-sphere nor a 7-space, so the fact that a 7 sphere does not embed into 7-space, certainly cannot be visualized by mere mortals such as myself.

Secondly, let me also point out that certain surfaces that are topologically 2-dimensional (that is, locally they look like a plane), cannot be embedded into a 3-dimensional space. A projective plane and a klein bottle are examples of these strange surfaces. They can, however, be embedded in 4 space. Thus, for these surfaces, the extrinsic dimension, defined above, would be 4.

In conclusion, let me mention that a theorem of Whitney states, roughly, that any n-dimensional smooth manifold can be embedded in a 2n-dimensional space. It turns out that this is in fact the best estimate.

For these reasons I urge everyone to stick to the "topologist's convention" and call a sphere - 2-dimensional and a circle - 1-dimensional. After all, we don't want a knotted circle, a sphere and a solid ball to all be 3-dimensional! But then again, I speak as an aspiring topologist :)

Cheers,

Michael

-- M G

hi

Aww, you commented here. As long as your comment remains on this page, I shall remember the reason I love you- for your quirkiness.

My, my you were so young back then, too.. How cute you must have been when you first posted this. You were just a tiny little kid, trying to find the magic in the world. And you found it in pi, so you started memorizing and memorizing. And now, you know around 1400 digits. You are so amazing... Sometimes I look into your eyes and now that a god somewhere out there exists. You are too perfect to occur from mere chance. Take your talents, your leadership, your intellect and share your gift with the world. Remember, dear, that life is short and that you've only got a limited time to experience everything that you can. There are days when I sometimes think that I hold you back. So please, leave me if you think that you are settling for less. Live your life to its fullest. You are so full of life and genius and spirit. If you waste your life, I think I would die a million deaths because of my sadness.

-- Jennifer Nguyen

Whisper PI to me

I remember being on Eve's site years ago. I swore that I heard something in my headphones. I cranked up the volume and heard Eve whispering digits of PI :)

I wonder if that audio file is still around?

Anyways, great job on the website Eve. There was always something magnetic about the website and your personality. Glad to see that all is well.

Rich

-- Richard Benson

Juanune

RealPlayer says that the audio file at http://www.eveandersson.com/music/juanune.mp3 is 3:14 long. I'm still trying to guess whether that's a coincidence.

-- Larry Hosken

Happy Pi Day, Eve!

-- Andrew Grumet

Happy Pi Day

It's been quite a while since I've visited your Pi pages. Since this is Pi day, I typed "eve pi" into google (of course your's was the first link) to reminisce about the early days of the web. I was shocked to see your picture (you appear to have lost your green telepathic antennae).

Happy Pi Day!!

Don

-- Don S

Pi Day!

Well, thanks to your test our Algebra 2 class devoted an entire class period to pi! We had to take one of your pi tests, measure circumfrences, and, in general, use pi. Fortunately for us, our teacher actually let us eat PIE. What's better than calculating and Key Lime pie?

-- Kathryn Shoemaker

More digits

You should have more digits for the pi trainer!! 9,999 digits is not enough :(

-- Sam Kwon

Pi trainer

Hi, I am new here. The Pi trainer was a fun feature, although I was able to enter 100 at a time very quickly and get all correct. I realize that I might get into difficulties later, so I think the function of taking for example 5 or 10 digits at the time might prove useful. Personally I tend to memorize them by "discovering" a rythm in which I go through the decimals in my head; very useful. However I doubt that I could use the same technique when I get to more than 200 or 300 decimals.

Very good website you have Eve!

-- Axel Hogberg

A Useful Link

Anyone who's got this far is obviously irrational (sic) enough to appreciate http://antwrp.gsfc.nasa.gov/htmltest/rjn_dig.html. (All you US taxpayers, this is what NASA is spending its time and money on... While I can see good cases for accurate calculations of pi, e etcetera, I challenge anyone to think of a use for root-6 to a million SFs.) Oddly the site _doesn't_ include any calculation of the one irrational number one would think would be of most use to an organisation whose primary purpose involves calculating curves...

-- Aidan Merritt

Boredom

I like pi. When the common teenager is amidst the horrible factors of extreme boredom, what can one do but occupy time during school? Pi is indeed a pleasantly time consuming pursuit. It can be very discreet. While you're watching some monotonous movie about the French Revolution during history, it's infinitely simple to just pull out a 3x5 card with a thousand digits out of your pocket and start memorizing. You don't even have to memorize. Just read the same set of ten digits over and over again while thinking about the freedom you will enjoy in two more periods. Sigh. And that is why I like pi.

-- David Horton

Pi Fundraiser

The world's first Pi Fundraiser!

Actually, it's a fundraiser for high school kids who love pi. They have produced a very funny pi shirt for which all the profits are being donated to their high school math program. The shirt is on the front page and is called "Pi is Constant".

The goal is to earn $3142 for the school, so please donate!

-- Josh Cummings

check out this music video about Pi

I saw this weird/funny music video about Pi the other day and it reminded me of you: http://www.keithschofield.com/pi/

-- Fjarlq Fjarlq

Hi,I am Tim Axoy!

Hi,I am Tim Axoy! I love pi! Here is how much I know pi to:3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679.... That is 100 digits. I like the number 7. How come there is a great deficiency of 7's in the first few hundred digits? For example,in the first 100 digits,there are only 8 7's,in the first 200 digits,there are only 12,in the first 300 digits,there are only 19,and in the first 400 digits,there are only 24. That is weird. Guess what? The first time that you find four of the same digit in a row in pi is 9999,which starts 762 places after the decimal point. Well,there is also a fifth 9 and a sixth 9,too. Therefore,it goes 999999. Another thing about pi is that from 19437 places after the decimal point to 19453 places after the decimal point,an interesting thing happens. It goes 99992128599999399. There are big clumps of 9's. Another number I like is the prime number 2477. Well,it turns out that the first time that you find 2477 in pi is starting 4905 places after the decimal point. Well,it turns out that there are three 2's immediately before that,not including the 2 in 2477,so starting 4902 places after the decimal point,it goes 2222477. There are six 9's in a row in pi. Bye,bye!

-- Timothy Axoy

Recent pi discovery

pi.ytmnd.com

It's not much, but the music has a hypnotic quality to it.

-- Sean Gundlach

My irational number

Challenge somebody to prove or refute.

A math friend claims the sequence 71x389x2190521/(5x3^4x11^2)x10^-6 approximates the following number which I came up with in grade school as the world's most "inituitive" irrational number.

1.2345678910111213141516171819...303132...10001001...

This number is not PI but it's non-random subsequences contain all the finite subsequences of PI

-- George Jost

mysterious envelope

I recently (early February, 2006) received an envelope. It had no return address; its postage (and cancellation) was from India.

It contained three xeroxed sheets of paper. There was no cover letter, no explanation, just the xeroxes themselves. Two of the sheets were from a pamphlet about squaring the circle, including a section noting that one R. S. J. Reddy had obtained superior results by using an approximation for pi of 3.14644661. The other sheet seemed to provide more information about R. Sarva Jagannadha Reddy and his efforts to show that a geometric approximation for pi is about 3.156844.

Some people might look at this mail and blanch, wondering "Have we been wrong about the value of pi all of this time?" I have more important things on my mind: I wonder, "Why did I receive this mail?"

It's addressed to "Doctor Larry Hosken". I am not a doctor nor a professor nor a what-have-you, doctor-wise. I am not an authority on pi. I admit that on this site, I wrote a simple python script that approximates pi by the Monte Carlo method. However, that script is only accurate to one decimal place. It happily spits out values of 3.11 and 3.16; it does so often. If Shri Reddy and/or his agents seek to impress an authority, they have chosen the wrong person. No one looks to Larry Hosken to find out what digit comes after the "1" in pi.

I guess my question is: has anyone else here received any similar mail recently?

-- Larry Hosken

Pi memorization

Hi. I'm a high school maths freak and i was wondering if anybody knows if there's a record for reciting pi at the highest speed. My best is 217 digits in a minute.

-- Luke Hutton

Mysterious indeed

This "R. S. J. Reddy" character claims to be able to prove in over sixty ways that the value of pi is 3.1464466...

Lucky you! I wish I received random mail about Pi :)

-- Lee Houghton

I like pi

Hey. I am in middle school and am obsessed with math (and pi) and have memorized by heart, the first 101 digits (the last digit is 9)! KEEP UP THE GOOD WORK!!!

Elliot

-- Elliot James

Fun Pi Stuff

First off, I like the site. I'm always interested in learning factoids. Pi is just one of those thigns that has always fascinated me.

Seeing as there are people who seem to like pi as much as me, I thought I'd pass along this recent website I just stumbled upon.

Enjoy!

http://ilikepi.patelive.com

-- Adam Cuberson

PI song

You might like this

http://pi.ytmnd.com/

-- adam snyder

Hi again

Hey everyone, I discovered this site quite some time ago, and it looks like there have been a lot of interesting comments since then. To one of the more recent posters I will mention that I can say about 350 digits in one minute.

I began memorizing pi somewhere around the age of 10, I guess, and right now I am 19. In all, I have memorized the first 1000 digits of pi, although I have had those memorized since I was 14ish. My record was 1400 once, but I tend to forget them when I don't practice, so right now I only know 1000. My goal is about 10k if I can find the time, but the record is around 80k, so I don't really think I'll ever get that far. Who knows, though?

I am currently double majoring in computer science and mathematics, so hopefully I will learn all sorts of interesting things about pi during my studies. I have always loved pi, so of course I own the books "A History of Pi" and "The Joy of Pi", although the former is more extensive. Pi is an obsession that many simply cannot understand. I find it hilarious when friends ask, "But why??" and I have no answer for them except for "Because I can!"

There really is no particularly good reason to know so many digits, but simply dedicating yourself to memorizing something so inexhaustable is great exercise for your brain. I know that my ability to learn quickly must partly come from this nerdy obsession that many of us here share. I remember this one time in high school, I printed out the first million and a half digits or so in the library, LOL! After that, they put a limit on how much we could print, LMAO.

Oh, yeah, and I definitely plan on buying one of those t-shirts mentioned above. I love the one that says "Approximation is for Wimps," haha.

Visit my pi page! (in progress)

-- Spencer Shepard

The late 0

0 appears very late in pi,32 places after the decimal point. It is late compared to e,where every digit appears by the 20th decimal place. Also,in many other constants the late digit is not late. Ln(2) takes 22 places,Euler's gamma takes 16,and sqrt(2) takes 18. However,there are some constants with later digits. Pi^2 takes 46 decimal places to get 2. This is so cool about late digits.

-- Timothy Axoy

re Spencer

350 digits/minute is very fast, almost 6 digits/sec! Maybe I can think that fast, but to recite it so that others could disitinguish every digit would be impossible (for me atleast).

-- Axel Hogberg

PI the movie

I could not see a reference to PI the movie

Here is a link to it

http://www.imdb.com/title/tt0138704/

on IMBD

A paranoid mathematician searches for a key number that will unlock the universal patterns found in nature.

A rather odd movie, but somewhat captivating.

Essential to a collector of all things PI,

Harvey Sather

-- Harv Sather

TeX the text processing system

TeX uses the digits of Pi for its versioning

http://en.wikipedia.org/wiki/TeX

Since version 3, TeX has used an idiosyncratic version numbering system, where updates have been indicated by adding an extra digit at the end of the decimal, so that the version number asymptotically approaches Pi.

The current version is 3.141592

Likewise, versions of METAFONT after 2.0 asymptotically approach e.

Harv Sather

-- Harv Sather

Hey my name's Sonali and its been pi day for about an hour and 35 minutes now. Its also my birthday! But anyway, I just watched the movie, Pi: Faith in Chaos, a couple of weeks ago. It was pretty cool. The plot was slightly hard to follow, and I didn't understand why he drilled through his head in the end, but it wasn't a waste of life like most Hollywood movies are. Anyway, I love seeing the world through numbers. People say it takes away the mystery but I think its kind of pretentious to assume that we will ever know everything about nature. I love how everything I have learned since I was two fits together so beautifully. And I'm only in calculus, theres so much more out there! How does something as simple as a plain circle have an element so irrational as pi? Isn't that crazy? I'm probably ranting but anyhow, I turn 16 today and the world is mine to explore so goodbye to all the Einstein lovers and math geniuses. Have a wonderfully irrational day!

-- Sonali Gupta

Happy Pi Day

The movie Pi: Faith in Chaos is really a nice introduction to the concept of thinking in terms of patterns. It's actually quite elegant to see the patterns found in nature.

A nice site to look at is: http://goldennumber.net/

Hi Eve, Happy Pi Day! Just letting you know, you inspired me to stay on track of my love for Math and Patterns! :D

-- Thomas Holloway

Best Pi Quiz on the Web!

Eve, I'm sure your large readership and the number of comments you're receiving already confirm the title of this comment but I've been trying to email you to congratulate you personally. Has your email address changed? Anyway, I just published a review of your Trivia Game and your website on my blog: http://mathnotations.blogspot.com/2008/03/best-pi-quiz-on-web.html You deserve the title, Best Pi Quiz on the Web! Thanks for the wonderful resource.

It must be gratifying to you to see how many educators and others are looking for interesting Pi Facts/Activities this week! Then they land on your site and are captured...

Dave Marain

-- Dave Marain

Pi

Another approximation is 335/113 = 3.1415929....

-- J J

MIT Song

Eve-

Somehow this MIT song has escaped being posted on your Pi page. Hopefully this adds to your site's poetic ambiance.

"E to the U, dU dX, E to the X, dX

Cosine! Secant! Tangent! Sine!

3-point-1-4-1-5-9!

Integral! Radical! ?, DV

Slipstick! Slide rule! M.I.T.!"

Steve Nicholls

Fellow TPM @ Google and MIT Alum

-- Stephen Nicholls

Great Pi Website

This is one of the best pi websites I've seen, and the pi trainer has helped me a lot. Using it, I've memorized 150 digits in four days; who knows, maybe I'll be up to 1000 by the end of the year! I started memorizing when I learned something interesting about pi and my birth on this website... I was born when my mother was 31 years old, on 4/15/92. Sound familiar? The first 7 digits of pi! I feel pretty special now. :)

-- Taylor Brandstetter

Awesome

I have only used the pi Trainer for about 2hrs and I have gone from 16 (what I used to know)to 100 decimal places off the top of my head -> THIS IS AN AWESOME TOOL!

-- Quade Hannan

Pi page, great pi site.

Just want to say it's wonderful to find the Pi Page still going, this is one of the best pi websites I've seen.

-- Listening

-- Mark Hanson

Like this website

This is a great website. The pi trainer is a wonderful training program. In a little more than an hour I memorized 150 numbers of pi and got 150/150 on pi trainer. I spent one hour on the program and 25 minutes away from computer before that memorizing 86 of the decimal numbers. 150 numbers in a relatively quick time is not bad I guess but I think I've memorized enough numbers for my goals. I used to be a top math student in college getting the highest score in class most of time and so I find this pi trainer to be a great program.

-- Albert Lee

Pi Contest and book

Love your Pi site! My newest book Unforgettable is a YA novel about a boy who remembers everything, even the digits of Pi! I'm doing a Pi giveaway in celebration of Pi Day on Mar. 14 - please send all Pi lovers: http://www.lorettaellsworth.com/books/unforgettable2.html

-- Loretta Ellsworth