People have enjoyed memorising the digits in pi since at least the beginning of the 19th century.

Back then only a few hundred digits were known, so it was barely more of a challenge than memorising a long poem.

But since then computers have calculated more digits of pi than could ever even be recited in a lifetime, let alone memorised, and now pi memorisation is only for the truly dedicated.

The world champion is Akira Haraguchi, who in 2006 recited 100,000 digits of pi from memory at a public event near Tokyo. It took him 16hrs 30mins.

This feat makes him the master pi-man, even though the Guinness Book of records has not validated his record. (The Pi World Records website has Chao Lu from China as number one, with a mere 67, 890 digits).

Pi memorisation is difficult - and this is why people do it - since there is no pattern in the digits. You need to invent your own methods to remember them. Haraguchi associates each digit with a syllable: 0, for example, can be read as o, ra, ri, ru, re, ro, wo, on or oh, and so on with the others from 1 to 9. He then makes stories from the words produced by the syllables.

As the man who has probably spent most time thinking about pi, I wanted to speak to him about Pi Day. So I sent him ten questions by email:

1) How will you celebrate Pi Day on March 14?



I haven’t done anything special on the day in the past. But this year I’ll ask my wife to increase the amount of dinnertime drink I can enjoy on that day.

2) Since you broke the pi world record in 2006 have you maintained an interest in pi? How many digits can you still remember? How often do you think about pi? Is it still the “religion of the universe” as you once called it?

Yes, my affection and affiliation with the Pi continues to this day. In 2010 I posted a video online via my iPad when I managed to recite 101,031 digits. I have improved further since, and I can recite about 111,700 digits. I have been reciting more than 15,000 digits per day (since 2006). That takes up about an hour every day.

To me, reciting pi’s digits has the same meaning as chanting the Buddhist mantra and meditating. I’m actually trying to do more these days, making it a daily goal to recite more than 25,000 digits, which takes me about three hours.

According to Zen Buddhism teachings, everything that exists in this world - the mountains, the rivers and all the living creatures - carries the spirit of the Buddha.

I’ve interpreted this to mean that everything that circles around carries the spirit of the Buddha. I think pi is the ultimate example of that.

Facebook Twitter Pinterest Akira Haraguchi at home revising. Photograph: Akira Haraguchi

3) Since 2006 what have you been up to? Are you still interested in memorisation?

Through the memorization of pi i I have been able to discover universal methods to improve memorization skills and draw out other abilities. I have been making lectures about such things around the nation.

4) It seems that the Guinness Book of Records has still not accepted your record. How do you feel about this? Do you think you will ever attempt a public memorisation again?

It can’t be helped because the Guinness World of Records has its own ideas. Of course it’s regrettable. Yes, I plan to attempt a public memorization again in the near future.

Akira Haraguchi signs his book The Memorization Skills of A Whopping World Title Holder - A Challenge to Memorize 100,000 Digits of Pi

5) In what way does pi give you answers to the spiritual questions you were asking yourself?

All things in this world, including ourselves, are aggregate sums of atoms, which are made up of rotating electrons. The ultimate history of mankind is moving toward a happy ending for people of all races. The earth, the galaxy and the universe all rotate. In other words, I think rotation is the absolute truth. So as long as I’m thinking about pi, I think I can live a life according to truth.

6) You invented a language for your pi memorisation based on associating each digit with particular sounds. Can you summarize some of the stories that you told within the digits of pi?

I have created about 800 stories, whose lead characters are mostly animals and plants. For the first 100 digits of pi, I have crafted a story about humans. Here is how the first 50 digits, starting with 3.14, reads: “Well, I, that fragile being who left my hometown to find a peace of mind, is going to die in the dark corners; it’s easy to die, but I stay positive.”

7) What do your wife and son think of your obsession with pi? Have you managed to persuade them that it is the “religion of the universe”?

My family are not interested in pi at all. To them my interest in pi seems to look like an “enormously harmless hobby,” and in that sense, they welcome it.

Akira Haraguchi’s crib notes: the digits of pi Photograph: Akira Haraguchi

8) Have you heard of the campaign to change the circle constant from pi to 2 x pi, called “tau”, which is the ratio between the circumference of a circle to the radius? What do you think of this?

I had no idea about it. But it sounds like the campaign has little relationship with my view of the nature.

9) In what way was all the time and effort you put in to memorising pi worth it?

To me it’s part of my “Buddhist training,” and it has helped me get a clear understanding of the meaning of life, as well as enjoy peace of mind and body. It has also brought me other benefits, as described in my answers to questions 3 and 10.

10) How do you spend your days at the moment?

I have managed to develop a certain methodology for improving cognitive abilities, so I have been trying to contribute to society by introducing something like the “Haraguchi method of recovering from dementia.”

Thanks to Tomoko Otake for the translations.

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