# You're reading: Posts Tagged: maths in the news

### All metro systems eventually have the same shape

The BBC and Scientific American report on a paper looking, “in an exploratory manner,” at the limiting shape of metro systems serving large cities. The BBC linked to the actual paper, which is nice of them. The Scientific American article goes into a bit more detail, though.

The authors contend that rather than the shape of subway networks being decided by central planning, which would produce a variety of shapes, the eventual shape of a subway network converges on an emergen structure consisting of a dense core with branches radiating from it.

### Modelling obesity

(No, this story is not about plus-size fashion week)

The New York Times has published an interview with Carson C. Chow, an applied mathematician who models the factors causing obesity in the human body. He claims that the main cause of America’s obesity problem is the overproduction of food.

Dr. Chow has written a post on his blog about the interview, adding some more detail about what exactly he does and backing up his claim that availability of food causes obesity. He also points a commentor asking for more scientific details about his research to the obesity category on his blog, where he talks about his papers.

Interview: A Mathematical Challenge to Obesity

### “Futurama theorem” slightly improved

The “Futurama theorem”, also known as Keeler’s Theorem after its creator, was a bit of maths invented for the Futurama episode The Prisoner of Benda, to solve a problem where the characters get their heads mixed up and need to swap them back without any one pair swapping heads twice. It was enthusiastically reported by the geeky press, and rightly so, because it’s a fun bit of real maths with a wonderful application. Dana Ernst has written some very good slides about the theorem, working from “what is a permutation?” up to the algorithm itself.

Anyway, some students from the University of California, San Diego have extended the result, giving a better algorithm for finding the minimum number of switches to put everyone’s head back in the right places, give optimal solutions for two particular situations, and give necessary and sufficient conditions for it being possible to represent the identity permutation as $m$ distinct transpositions in $S_n$.

via James Grime

### Inclusion and Exclusion and the new GMAT

Dublin native Colm Mulcahy has been in the Department of Mathematics at Spelman College since 1988. His interests include algebra, number theory, geometry and mathematical card principles and effects. Follow him on Twitter at @CardColm and also check out @WWMGT

The last question, under the heading “Two-Part Analysis”, at the end of this NYT article (from July 2011) on the new GMAT seems to be deliberately worded in a way that forces one to read and think very carefully.

It takes a while to even process the question as it’s asked! I’m assuming that was intentional.

I’m curious how “they” intended people to solve this. Exclude impossible answers until only one is still Included?  I guess so.

### Math/Maths 92: Put Alan Turing on a Buckliball

A new episode of the Math/Maths Podcast has been released.

A conversation about mathematics between the UK and USA from Pulse-Project.org. This week Samuel and Peter spoke about: Thomas M. Rodgers (3 Aug 1944 – 10 Apr 2012); Racism in academic mathematics; Buckliball; What sank the Titanic?; Physicist Uses Math to Beat Traffic Ticket; Best and Worst Jobs of 2012; Numerical prodigy sets Guinness record for subtraction; e-petition: Put Alan Turing on bitcoins; Bedtime Math; Minds of Modern Mathematics iPad app; Turing-Tape Games; BAMC writing prize; Maths Busking at Engage U; Mathematicians Take a Stand; 3D printed Sierpinksi tetrahedron, Mobius strips loaded with ball-bearing; Sophie’s Diary; Amelia and the Mapmaker; Carnival of Mathematics 85; America’s struggle to make math fun; Spammers are targeting mathematicians; and more.

Get this episode: Math/Maths 92: Put Alan Turing on a Buckliball

### Racism in academic mathematics in America

Jonathan Farley has written a shocking account of racism in academic mathematics. Framed as a discussion of barriers to winning the Fields medal for black mathematicians, Farley tells three stories, of an MAA conference in 1951 Tennessee, of David Blackwell and his own career. The stories are shocking because, although I am aware terrible racism happened in the past, I feel like you’d hope these stories would be irrelevant in recent decades.

Read the article: Black mathematicians: the kind of problems they wish didn’t need solving.

### Math/Maths 91: Gathering for Gardner 10

A new episode of the Math/Maths Podcast has been released.

A conversation about mathematics between the UK and USA from Pulse-Project.org. First Samuel and Peter were joined by special guest Edmund Harriss to talk about his time at Gathering for Gardner 10 and Five math things to do before you die, then they spoke with eachother about: Snowflake Growth Successfully Modeled from Physical Laws; A Joint Position Statement of the Mathematical Association of America and the National Council of Teachers of Mathematics on Teaching Calculus; All the Math Taught at University Can Be Outsourced. What Now?; Mathematical Fonts; Intersections, Henry Moore and British modernism exhibition; Emmy Noether: The Mighty Mathematician You’ve Never Heard Of; Rechner Calculator; Math Awareness Month: Mathematics, Statistics, and the Data Deluge; and much more.

Get this episode: Math/Maths 91: Gathering for Gardner 10