Today’s Oxford English Dictionary “Word of the Day” is quod erat demonstrandum. (I’m not sure if this link will stop working at the end of the day.) Apparently it took some time to find the right translation of Euclid’s Greek ὅπερ ἔδει δεῖξαι. Perhaps my art department, which knows ancient Greek, has something to say.
Via Emanuel Kowalski.
From quora, which planet spends the greatest share of time closest to Earth? (Hint: it’s not Pluto.)
From the math graduate students at Carnegie Mellon, slides for the convergence of a random walk on slides to a presentation and video of the talk based on these slides.
A few talks from the MIT Sloan sports analytics conference:
(Unfortunately these videos were filmed with a single camera on the speaker, and some of them refer to visuals that can’t be seen. They still make sense, though.
Stephanie Coontz on how averages can be misleading – in this case when averaging people’s experiences.
findthebest.com offers unbiased, data-driven comparison of lots of things. (But despite being in Santa Barbara they don’t seem to have enough information to find the best Santa Barbara wine! I suppose I’ll just have to go down there and drink more.)
John Baez on (the number) 42.
The always excellent DataGenetics asks how far can you overhang blocks?
Keith Devlin has some remarks (from his course “Introduction to Mathematical Thinking”) on the brilliance of calculus.
An oldie but goodie: Diaconis and Efron, 1983, “Computer Intensive Methods in Statistics” on the bootstrap and other advances in theoretical statistics made possible by the computer. I was particularly struck by a claim that a computation of a bootstrapped confidence interval for a correlation coefficient took less than a second and cost less than a dollar. That seems like a fantastic deal if the alternative is hand computation…
(also, this was written for Scientific American! They’ve gone downhill…)
Colm Mulcahy on the perennial student question, what do I have to do to get an A in this class?
A puzzle about balls from urns from MathOverflow and Gil Kalai’s blog post on the same problem.
The Eurovision final predicted with Bayesian statistics.
I’m in London, where according to the Guardian we’re supposed to get half a month’s rain today.
Sounds scary, doesn’t it? That makes it sound like it’s going to rain fifteen times what it does on a typical rainy day; of course it means that we’re supposed to get fifteen times what London gets on a typical day, including the days when it doesn’t rain.
And in fact the forecast calls for only an inch. (Is that a lot for a single event here? I don’t know – my usual sources for weather data are US-centric.) Certainly a lot, but not apocalyptic.
And since rain usually comes in storms, it stands to reason that the single biggest rain event in any given month would be a large portion of the rain for the whole month. I’d wager that in a typical month, the biggest rain event is at least a quarter of the total rain for the month.
(Incidentally, there are bookmakers everywhere here. Can I actually bet on the weather?)
Every odd integer greater than 5 is the sum of three primes, says Harald Helfgott. And there are infinitely many prime gaps less than seventy million, says Yitang Zhang. (As Dan Goldston quips in this blog post from Nature, this is within a factor of thirty-five million of the target.
Premise is mapping the produce manifold.
Airbnb is figuring out where you want to go in places you’ve never been.
Diffuse Prior figured out when The Simpsons jumped the shark.
Jim Holt reviewed Mandelbrot’s memoir for the New York Review of Books.
From Smithsonian magazine, Life in the city is essentially one giant math problem.
Visualizations of planar choreographies (Certain symmetric solutions to the n-body problem.) Via hacker news; here’s the paper by James Montaldi and Katrina Steckles.
From Laura McLay (Punk Rock OR), Braess’ paradox in physical systems and in basketball.
Sally Thomason on ultraconserved words at Language Log.
a MathOverflow list of modern mathematical achievements accessible to undergraduates.
Are hot hands in sports real after all?
How often does it happen that theoldest person alive dies?, from math.SE via Hacker News
The paradox of the proof, on Mochizuki’s proof of the ABC conjecture.
Sean Gourley (of quid) on data scientists as the new cartographers.
The shorter your first name, the bigger the paycheck, says The Ladders, a career website. (via Quartz. This is being publicized as “each extra letter in your name costs you $3,600”. So could I get $10,800 more by going by “Mike”? Seems unlikely – and they are claiming that the effect holds up even with nicknames.
There does seem to be some sort of pattern – average salary peaks for five-letter names, dropping off both for longer and shorter names. Not surprisingly, five letters is pretty close to average name length. I took a look at the Social Security Administration’s list of 1000 most popular names for each sex, from 1960. (The original post was looking at “C-level” employees, who are going to skew somewhat old relative to the rest of the labor force.) Average male name length in this sample was 5.59 letters; average female name length was 5.73 letters. Furthermore, among male names, the shorter names tend to be more common than the longer ones. (This doesn’t hold true for female names.)
My theory, then — which I don’t have the data to test — is that people with more common names tend to do better at the C-level. Perhaps parents who give their kids common names tend to be more conformist and raise their kids with the sort of values that will get them such a job. Or perhaps kids with more common names end up more self-confident, since they’re not constantly thinking that their names are weird — and self-confidence is important for career advancement.
(None of this should be taken to be comments on my own name, Michael, which was very common in the early eighties.)
Sears Merritt on safe leads in basketball, expanding on Bill James’ method for telling when a lead is safe.
Kevin Jamieson makes a two-dimensional map of styles of beer. I’d like to see this for wine.
You can buy a 3D-printed triple gear (three gears which touch in pairs and yet can all turn simultaneously! or
read about how Saul Schleimer and Henry Segerman figured out how to make one.
Ben Orlin, a math teacher, writes about what it feels like to be bad at math.
chartsnthings made some charts of skill and chance in the NFL draft.
Melinda Theilbar explained how folklore can be dangerous to one’s business.
Ravi Vakil wrote about the mathematics of (a certain kind of) doodling.
