**jm + mathematics**
5

Sci-Fi Writer Greg Egan and 4chan anon Math Whiz Advance Permutation Problem | Quanta Magazine

mathematics
internet
math
greg-egan
anime
bizarre
4chan
superpermutation
permutation
proofs

4 days ago by jm

On September 16, 2011, an anime fan posted a math question to the online bulletin board 4chan about the cult classic television series 'The Melancholy of Haruhi Suzumiya'. Season one of the show, which involves time travel, had originally aired in non-chronological order, and a re-broadcast and a DVD version had each further rearranged the episodes. Fans were arguing online about the best order to watch the episodes, and the 4chan poster wondered: If viewers wanted to see the series in every possible order, what is the shortest list of episodes they’d have to watch?

In less than an hour, an anonymous person offered an answer — not a complete solution, but a lower bound on the number of episodes required. The argument, which covered series with any number of episodes, showed that for the 14-episode first season of Haruhi, viewers would have to watch at least 93,884,313,611 episodes to see all possible orderings. “Please look over [the proof] for any loopholes I might have missed,” the anonymous poster wrote.

The proof slipped under the radar of the mathematics community for seven years — apparently only one professional mathematician spotted it at the time, and he didn’t check it carefully. But in a plot twist last month, the Australian science fiction novelist Greg Egan proved a new upper bound on the number of episodes required. Egan’s discovery renewed interest in the problem and drew attention to the lower bound posted anonymously in 2011. Both proofs are now being hailed as significant advances on a puzzle mathematicians have been studying for at least 25 years.

4 days ago by jm

The inventor of dynamic programming, had to hide the fact he was inventing it from the Secretary of Defense

june 2017 by jm

"His face would suffuse, he would turn red, and he would get violent if people used the term "research" in his presence. You can imagine how he felt, then, about the term "mathematical". [....] I felt I had to do something to shield Wilson and the Air Force from the fact that I was really doing mathematics inside RAND"

rand
funny
history
insane
dr-strangelove
1950s
dynamic-programming
mathematics
algorithms
june 2017 by jm

The Mathematical Hacker

december 2012 by jm

'The trouble with the Lisp-hacker tradition is that it is overly focused on the problem of programming -- compilers, abstraction, editors, and so forth -- rather than the problems outside the programmer's cubicle. I conjecture that the Lisp-school essayists -- Raymond, Graham, and Yegge -- have not “needed mathematics” because they spend their time worrying about how to make code more abstract. This kind of thinking may lead to compact, powerful code bases, but in the language of economics, there is an opportunity cost.'

mathematics
coding
maths
essay
hackers
lisp
fortran
december 2012 by jm

Science funding doesn't add up - The Irish Times

july 2012 by jm

'[Science Foundation Ireland] said it was continuing to support basic research, but there are a number of leading scientists here who were refused funding despite having qualified for it in the past.

Dr Mike Peardon of the School of Mathematics was recently been turned down, having been “administratively withdrawn”. This means the application for funding was rejected at the first post during initial consideration and before it had a chance to be assessed by external experts. Several others in his department suffered a similar fate. “The school of mathematics at Trinity is ranked the 15th best maths department in the world and now we are not fundable by Science Foundation Ireland,” he said.

“The cases I heard of have all been in pure maths,” said Prof Lorraine Hanlon in UCD’s school of physics. “All reported that the people in pure maths were returned unreviewed.” She believes other areas may also come under pressure. “Pure maths is the thin end of the wedge. The Government says mathematics is fundamental, but on the other side says we dont really care enough to support it. That is a schizophrenic approach,” she said.'

mathematics
ireland
science
research
academia
funding
tcd
ucd
sfi
Dr Mike Peardon of the School of Mathematics was recently been turned down, having been “administratively withdrawn”. This means the application for funding was rejected at the first post during initial consideration and before it had a chance to be assessed by external experts. Several others in his department suffered a similar fate. “The school of mathematics at Trinity is ranked the 15th best maths department in the world and now we are not fundable by Science Foundation Ireland,” he said.

“The cases I heard of have all been in pure maths,” said Prof Lorraine Hanlon in UCD’s school of physics. “All reported that the people in pure maths were returned unreviewed.” She believes other areas may also come under pressure. “Pure maths is the thin end of the wedge. The Government says mathematics is fundamental, but on the other side says we dont really care enough to support it. That is a schizophrenic approach,” she said.'

july 2012 by jm

Kaprekar's constant

august 2010 by jm

'6174 .. is notable for the following property: Take any four-digit number, using at least two different digits. (Leading zeros are allowed.); Arrange the digits in ascending and then in descending order to get two four-digit numbers, adding leading zeros if necessary; Subtract the smaller number from the bigger number; Go back to step 2. The process will reach 6174 in at most 7 iterations'

6174
constants
cool
maths
mathematics
numbers
kaprekar
wow
from delicious
august 2010 by jm

**related tags**

Copy this bookmark: