With Pi in MIND

Jaipur resident Rahul Sharma would often struggle to keep awake as elder brother Suresh Kumar Sharma recited a never-ending stream of digits for hours on end. After all, it was Rahul's task to ensure that his brother doesn't falter. And in case he did, it would mean that he'd have to start over from 3.1415926535...

When he was just 21, Suresh Sharma became the youngest person to set a record for reciting by memory the most digits of Pi. The once-IIT aspirant rattled off 70,030 digits in 17 hours 14 minutes at a premise rented especially for the record attempt in Jaipur on October 21, 2015. “I kept my eyes shut during the first five hours partly because I was nervous and partly because I wanted to get in the rhythm,” says Sharma, who credits Rahul and their 80-year-old grandfather for abetting his endeavour.

Today, Sharma's name features at the top of the Pi World Ranking list. Sawai Madhopur resident Rajveer Meena's name figures next for reciting 70,000 digits of Pi in March 2015. Of the top 10 rank holders on the list, five are Indians, two Japanese, and the rest are nationals of China, the Netherlands and Great Britain. Of the five Indians, three are world record holders. But don't let that allow you to conclude that India dominates Pi rankings; that honour rests with the United States of America, which has 723 individuals on the list, some of whom have recited Pi to 20 digits in a matter of seconds. The Pi fellowship is indeed a global one, with individuals from such nations as Lithuania and Honduras to those from Namibia and, well, Greece, featuring in world rankings.

But why Pi — the ratio of a circle's circumference to its diameter? What is it that makes perfectly rational humans pursue this perfectly irrational number? And can finite human potential truly master the infinity of the mathematical constant?

A good challenge

For the most part, those who recite Pi are ordinary people who lead ordinary lives but, who, nevertheless, have extraordinary memory skills. It's not for fame or fortune that individuals chase Pi. Rather, most see in Pi's limitlessness the possibility of what the human mind is capable of achieving — Sharma's record for 70,030 digits isn't the end of the spectrum. Japanese Akira Haraguchi recited 100,000 digits of Pi in 2006, and has since recited over 100,000 digits. It is unclear why his feats have not been validated by Guinness. 

Those who dive into the pool of Pi digits are the ones who are already aware of their potential. Like Dr Rajan Mahadevan, who, as a five-year-old, memorised the number plates of all the cars that had brought 40 guests to a house party his parents were hosting in Mangalore. Or Rajveer Meena, who was aware since childhood of his sharp memory. “It was after I attended a memory training workshop that I thought of building on my capacity, and Pi was an obvious choice,” says the 28-year-old.

“It's the toughest memory record, and makes for an excellent challenge,” says Krishan Chahal, who recited Pi's 43,000 digits in June 2006. Chahal was drawn to the extreme test after he set a Limca record, in 2004, for memorising a deck of cards forwards and backwards in 84 seconds. The deck of cards feat, says Chahal, was “good for speed” but didn't test “long-term memory”. “Memorising Pi up to 20,000 digits is not a big deal, but memorising between 20,000-40,000 Pi digits is equivalent to double the complexity,” says the 37-year-old.

For Sharma, the imperative was entirely different. Studying for IIT-JEE in Kota, Rajasthan, he realised that he'd forgotten much of what he had studied just a few months earlier. He was also distressed by the suicides of fellow aspirants who, under pressure to perform but let down by their memory, had ended their lives. “I was moved by the tears and fears of students, who despite putting in upto 17 hours to study each day, were unable to recall that information,” says Sharma. “I wanted to help others. So I picked this task, of how to remember anything and how to recall it at any point of time, as a challenge.”

Illustration & Design: Ganesh Gamare

Tricks & techniques

There are no tricks, but there are several techniques to commit to memory the digits of Pi, including assigning alphabetic values to numbers, sound mapping, grouping numbers into chunks or linking numbers to certain information or trivia. Piphilology is a vast and eclectic universe of mnemonic techniques dedicated to mastering Pi. Among its many stars are mathematician Mike Keith's Cadaeic Cadenza, a short story written in 'Pilish' — in which the lengths of words match the digits of Pi, Andrew Huang's song Pi Mnemonic Song, mnemonic haikus called Piku; a vast number of 'Piems' (Pi poems) and verses in several languages, including in Sanskrit, in which the Katapayadi System when applied to the digits of Pi results in a hymn to Lord Krishna.

Sharma, who says he has come to acquire a photographic memory and relies on the power of imagination, employed extensive mnemonic techniques to remember Pi. Chahal tried several techniques before realising that they didn't work for him beyond 5,000 digits. So he spent months to devise an ingenious “grid” system. Dr Mahadevan, who held the world record from 1981 to 1987 for reciting 31,811 digits, says he would chunk the digits and rehearse a few times.

“The problem for me was that, a given string of digits, say, 5-7-6-4 could remind me of something at one time and some other thing at a different time. For example, the first seven digits of Pi are 3.141592. Right now, I think of St Louis (area code 314) and 1592 is the year Shah Jahan—the emperor who built the Taj Mahal—was born in,” says Dr Mahadevan, a distinguished lecturer at the University of Tennessee's department of psychology. “I don’t believe that was how I chunked those digits when I first memorised Pi. For one, I had memorised the first 50 digits of Pi from a computer printout, in which the digits were in groups of five i.e. 3. 14159 26535. I did not know the area code of St Louis back in 1979, and 159 and 2 are parts of different chunks and so it is highly improbable that I was reminded of Shah Jahan.”

Gift, grit & a long grind

It’s a foxy pursuit. For every Dr Mahadevan and Meena, who are convinced that the capacity to memorise is inborn, there is a Sharma and a Chahal, who believe the skill can be learnt. Both Sharma and Chahal have written books and taught thousands of students and adults techniques for memorisation, retention and recall. Sharma is candid about his “weak student” stature in a government school and says the same of his 18-year-old brother Rahul. “I've taught the techniques to Rahul, and he now holds the record for reciting the periodic table in the shortest possible time — 28 seconds,” he says. “My students too have shattered my record for square root of two in a similar vein.”

Dr Mahadevan offers another perspective. “It is not necessarily true that the earlier champions had a talent for memorisation. Rather, they demonstrated a level of performance that many believed was humanly impossible,” he says. “But when a lot of people started demonstrating striking feats of memory — for playing cards, Pi, and so on, then some researchers argued that it is all about practice.”

Whether you consider it an inborn talent or a honed skill, practice and perseverance are the only paths to mastering Pi.

Meena took nearly six years to confidently reach the 70,000-digit mark. Sharma would wake at 2am and start memorising about 2,000-3,000 digits per day, reciting until 10pm, taking just an hour’s break during the day, for two months until he was confident. Dr Mahadevan would memorise anything between 150 to a 1,000 or at the most 4,000 digits each day, and it took him 10 months to get to a point where he could recite 40,000 digits without errors. 

“You must have passion, otherwise it’s not possible to memorise Pi,” says Chahal, who recalls dreaming of numbers while asleep in 2005-2006 when he was committing it to memory. “A dogged determination is the only trait that will see you through in the face of frustrations and setbacks.” Incidentally, Chahal took half the time – five hours and 21 minutes – to recite 43,000 Pi digits to go past the previous record holder, Japanese Hiroyuki Goto, who had taken nearly 11 hours to recite 42,195 digits of Pi. So also, while Meena took about 10 hours to recite 70,000 digits, it took Sharma a little more than 17 hours to reach the 70,030 mark – effectively seven hours for 30 additional digits. Curiously, the Guinness Book of Records doesn’t link Pi recitation attempts to the time taken to master and recite the digits. It is solely concerned with the number of digits that’ve been correctly recalled. 

As with everything, memory is a limited resource. “Extraordinary memory is very specific to an area in which a person has interest or holds much knowledge of,” says Dr Mahadevan. “Outside of that particular area, the

person’s memory isn’t outstanding.” This explains why Meena, who also finds mention in the Limca Book of Records for remembering the most number of random things – 1125 – doesn't always remember to call his friends on their birthdays. Or that Dr Mahadevan has to wonder where he put his keys. “Fortunately, I keep them so safe that I never lose them!”

Memory and intelligence 

“Memory is a necessary condition but not a sufficient condition for intelligent thought and action,” says Dr Rajan Mahadevan. “For instance, fuel is a necessary condition for a vehicle to run but it isn’t a sufficient condition. A sufficient condition would include other necessary conditions such as tyres for the vehicle, an engine that works, and so on.”

Pi-time trivia

Aryabhatta worked on the approximation for Pi, and may have come to the conclusion that Pi is irrational

On April 24, 2014, Australian James Smith recited the first 3,000 digits of Pi forwards (in 1 hour 45 minutes) and backwards (in 2 hours 48 minutes) 

American physicist Larry Shaw was the first to organise a large-scale celebration of Pi Day on March 14, 1988, at the San Francisco Exploratorium. Shaw and the Exploratorium staff walked about one of its circular spaces, munching on fruit pies.