Alexis Lemaire
Encyclopedia
Alexis Lemaire is a mental calculation world recordholder. He holds a Ph.D in Computer Science related to artificial intelligence
from the University of Reims. He is also the owner of world records for mentally calculating the 13th root
of 100-digit numbers and 200-digit numbers.
On 10 May 2002, he calculated the 13th root of a 100-digit number in 13.55 seconds, beating the record held by Willem Klein
(88.8 seconds) and the somewhat less official record of Gert Mittring
(39 seconds). On 23 November 2004, Mittring tried to beat Lemaire's record, but his time of 11.8 seconds was not counted as official, as one organization's rules had decided to stop recognising records for root extraction of random numbers due to the difficulty of standardising the challenge. Less than a month later (17 December 2004) Lemaire beat his own record, with a time of 3.625 seconds—that's all it took for him to read the number, calculate its root, and recount the answer. He found the 13th root of the 100-digit number 3,893,458,979,352,680,277,349,663,255,651,930,553,265,700,608,215,449,817,188,566,054,427,172,046,103,952,232,604,799,107,453,543,533, which is 45,792,573.
Following this achievement, Lemaire gave up trying to improve his performance at calculating roots of 100-digit numbers, and moved on to 200-digit numbers with many attempts as described on the rules page.(see 13th root
and ) . Like an athlete, he trains his brain daily for this task. On 6 April 2005, he calculated the 13th root of a 200-digit number in 8 minutes 33 seconds.
By 30 July 2007, Alexis got his time down to 77.99 seconds at the Museum of the History of Science, Oxford
and by 15 November his time was further decreased to 72.4 seconds.
His latest achievement came on 10 December 2007, where he mentally extracted the 13th root of a random 200-digit number in 70.2 seconds
.
The so-called 'mathlete' produced the answer of 2,407,899,883,032,220 at London's Science Museum.
A computer was used to produce the random 200-digit number, from which he tried to extract the 13th root. The museum's curator of mathematics, Jane Wess, said, "He sat down and it was all very quiet -- and all of a sudden he amazingly just cracked it. I believe that it is the highest sum calculated mentally. He seems to have a large memory and he's made this his life's ambition. It's quite remarkable to see it happen. A very small number of people have this extraordinary ability; nowadays there is only a handful."
Lemaire says that his mental feats also have very useful applications in artificial intelligence, his chosen field.
Artificial intelligence
Artificial intelligence is the intelligence of machines and the branch of computer science that aims to create it. AI textbooks define the field as "the study and design of intelligent agents" where an intelligent agent is a system that perceives its environment and takes actions that maximize its...
from the University of Reims. He is also the owner of world records for mentally calculating the 13th root
13th root
Extracting the 13th root of a number is a famous category for the mental calculation world records. The challenge consists of being given a large number and asked to return the number that, when taken to the 13th power, equals the given number...
of 100-digit numbers and 200-digit numbers.
On 10 May 2002, he calculated the 13th root of a 100-digit number in 13.55 seconds, beating the record held by Willem Klein
Willem Klein
Willem Klein , also known as Wim Klein or under his stage names Pascal and Willy Wortel, was a Dutch mathematician, famous for being able to carry out very complicated calculations in his head very fast. On 27 August 1976, he calculated the 73rd root of a 500-digit number in 2 minutes and 43 seconds...
(88.8 seconds) and the somewhat less official record of Gert Mittring
Gert Mittring
Gert Mittring is a German mental calculator. He won the MSO mental calculation gold medal in every year from 2004 to 2011. In 2004 he held 24 recognized world records for calculation. He has doctorates in psychology and education...
(39 seconds). On 23 November 2004, Mittring tried to beat Lemaire's record, but his time of 11.8 seconds was not counted as official, as one organization's rules had decided to stop recognising records for root extraction of random numbers due to the difficulty of standardising the challenge. Less than a month later (17 December 2004) Lemaire beat his own record, with a time of 3.625 seconds—that's all it took for him to read the number, calculate its root, and recount the answer. He found the 13th root of the 100-digit number 3,893,458,979,352,680,277,349,663,255,651,930,553,265,700,608,215,449,817,188,566,054,427,172,046,103,952,232,604,799,107,453,543,533, which is 45,792,573.
Following this achievement, Lemaire gave up trying to improve his performance at calculating roots of 100-digit numbers, and moved on to 200-digit numbers with many attempts as described on the rules page.(see 13th root
13th root
Extracting the 13th root of a number is a famous category for the mental calculation world records. The challenge consists of being given a large number and asked to return the number that, when taken to the 13th power, equals the given number...
and ) . Like an athlete, he trains his brain daily for this task. On 6 April 2005, he calculated the 13th root of a 200-digit number in 8 minutes 33 seconds.
By 30 July 2007, Alexis got his time down to 77.99 seconds at the Museum of the History of Science, Oxford
and by 15 November his time was further decreased to 72.4 seconds.
His latest achievement came on 10 December 2007, where he mentally extracted the 13th root of a random 200-digit number in 70.2 seconds
.
The so-called 'mathlete' produced the answer of 2,407,899,883,032,220 at London's Science Museum.
A computer was used to produce the random 200-digit number, from which he tried to extract the 13th root. The museum's curator of mathematics, Jane Wess, said, "He sat down and it was all very quiet -- and all of a sudden he amazingly just cracked it. I believe that it is the highest sum calculated mentally. He seems to have a large memory and he's made this his life's ambition. It's quite remarkable to see it happen. A very small number of people have this extraordinary ability; nowadays there is only a handful."
Lemaire says that his mental feats also have very useful applications in artificial intelligence, his chosen field.