Revolutions

Because it's Friday: Game theory

Game Theory is the mathematical study of how agents in a system make choices for their actions, in light of the fact that other agents are also making competitive choices of their actions. As the name suggests, the "system" is often some kind of game and the "agents" are players, but game theory is also used to explain the behaviour of crowd motion, business dealings, foreign relations, and even the evolution of altruism. (There's a excellent chapter involving game theory in The Selfish Gene.)

The textbook example of game theory is the Prisoner's Dilemma. The UK game show "Golden Balls" includes a form of the Prisoner's Dilemma where the stake is prizemoney instead of freedom. Each player may independently choose to "split" or "steal" the prize, but if both steal each goes away empty-handed. You might think there aren't many strategic options to guarantee a win in a game like this, but one player found a way:

 

It's an elegant strategy. Nick is apparently altruistic (or at least risk-averse), and wants to share the prizemoney. But altruistic actions are open to subversion by a selfish opponent. Ibraham, unable to discern Nick's apparent "mutually assured destruction" strategy, has no option but to behave altruistically. I wonder if this strategy has ever been attempted again on the show; but now that this strategy is in the "gene pool" of strategic options, it would likely be less effective the next time around. And that's one of the subtle beauties of Game Theory.

via Business Insider: British Gameshow Contestant Puts On Badass Display Of Game Theory

Because it's Friday: Australian PSAs from the 80s

When I was a kid growing up in Australia, it seemed like every commercial break during the Saturday morning cartoon's or after-school shows was punctuated by some PSA encouraging us to lead a healthier life. These "community service announcements" were government-sponsored, and often paired a low-budget animations with a catchy jingle. Strangely enough, lots of Australians (me included) remember them fondly, and can still recite the songs on demand. Here are a few of my favourites:

"Slip Slop Slap" made avoiding skin cancer fun (an important lesson in the Sunburnt Country):

 

There were a whole series of these "Life. Be in it." ads, encouraging us all to get out of the house and do something lest we end up like Norm. (Seems like these ads are undergoing a revival.) I'm pretty sure there was one in the series encouraging Australians to have "one alcohol free day a week", but I'm either misremembering or it's not on YouTube.

 

But by a long shot, my absolute favourite was the Vitamins Song:

 

I always hoped there'd be a sequel where the Slip Slop Slap Magpie and Vitamin D resolved their differences in a Battle Royale, but sadly it never came to be. Enjoy your weekend!

 

Geostatistics and the 500-mile email problem

In the mid-1990s, a Statistics professor at UNC reported an IT problem: he couldn't send email more than 500 miles away. He'd had geostatisticians plot the sites where emails could be sent successfully and where they bounced, and found they described a circle a radius slightly over 500 miles. Some sites within the circle could sporadically receive email, but definitely none outside them. The solution to the problem, which involves old sendmail.cf formats and the speed of light, is well worth a read.

Because it's Friday: Five musicians, one guitar

Check out this cover of Goyte's "Somebody That I Used to Know", played on a single guitar by all five members of Walk Off The Earth:

  

Incidentally, the Gotye original version is the first song by an Australian artist to reach #1 on the US charts since Savage Garden in 2000. There's so much good Australian music it's a shame more of it doesn't make it to the charts over here in the US. But this is still a great song, so enjoy it as a kick-off to your weekend!

Because it's Friday: Pharoah's Serpent

When Mercury thiocynate is heated, it undergoes an exothermic reaction with surprising results:

 

This is actually a centuries-old fireworks effect, the Pharaoh's Serpent. But because of the toxic gases produced during the reaction, it is rarely used today. Still, it's cool to see.

Because it's Friday: Visualizing ocean currents

In yesterday's post about the visualization of sailing ship data, some of the commenters (and me, too!) wondered about the routes the ships took; for example, giving the west coast of Africa a wide berth just to round the Cape of Good Hope. This NASA visualization of simulated ocean currents, thought it's for the years 2005-2007, provides some perspective.

 

It's a shame the video isn't set to music: it's both mesmerizing and relaxing to watch. More details about the simulation (including some very cool animations of surface temperatures, which sadly don't appear to be on YouTube) at the link below.

NASA: Perpetual Ocean

Because it's Friday: I ice my sense let and it doesn't come with pizza

Even if you don't speak a foreign language, I'm sure you hear a French speaker and know, "that sounds like French". Same goes for many other languages. But have you ever wondered how English sounds to a non-English speaker? In 1972, Italian singer songwriter Adriano Celentano released the song Prisencolinensinainciusol comprised entirely of Italian nonsense words that sound uncannily like English would, if you couldn't understand the words. And now thanks to the mahic of YouTube, you can hear the song along with its gloriously funky music video:

 

It kinda sounds like Bob Dylan singing the Black Keys, but with words that are almost, but not quite, identifiable. Now for the mind-blowing part: watch the same video again, but this time with subtitles provided by YouTube user emeryemery:

 

It's like someone slipped a Babel Fish into your ear. It's the same song, and the same Italian words, but now the words are suddenly comprehensible English ... still nonesense, but definitely worlds. It's quite the mind-twist. It's kind of the same effect as the Bad Lip Reading videos, where perfectly ordinary speeches by politicians get converted into nonsense.

That's all for this week. Enjoy your weekend!

Because it's Friday: Copyright vs creativity

When the USA codified its copyright and patent laws in the 18th century, the goal was to create a robust public domain that all of society could benefit from, while still giving inventors and content creators a window in which to capitalize on their creative investment. Filmmaker Kirby Ferguson concludes his excellent Everything is a Remix series with a look at how over the years the laws have turned to preventing content from entering the public domain and protecting creators indefinitely:

 

Much of the change in the laws is a result of the influence of media companies, usually backed by the claim that copying (legal or otherwise) costs billions of dollars and thousands of jobs. Rob Reid takes a look at the numbers behind those claims in his humorous TED talk, Copyright Math (TM):

Because it's Friday: Please don't write like a scientist

When Adam Rubin was a PhD student, his advisor accused him of "writing like a poet" for using a non-scientific word in this thesis:

The word was “lone,” as in “PvPlm is the lone plasmepsin in the food vacuole of Plasmodium vivax.” It was a filthy word. A non-scientific word. A flowery word, a lyrical word, a word worthy of — ugh — an MFA student.

Rubin goes on to provide 12 tips to follow if you want to avoid accusations of literary or poetic writing in your scientific papers, such as:

Some journals, such as Science, officially eschew the passive voice. Others print only the passive voice. So find a healthy compromise by writing in semi-passive voice.

ACTIVE VOICE: We did this experiment.
PASSIVE VOICE: This experiment was done by us.
SEMI-PASSIVE VOICE: Done by us, this experiment was.

Yes, for the semi-passive voice, you’ll want to emulate Yoda. Yoda, you’ll want to emulate.

... and ...

Most journals use the past tense. To add flair to your writing, try writing your entire article in the Third Conditional Progressive Interrogative tense. Instead of, “We did this experiment,” you’d write, “Would we have been doing this experiment?” This may seem more convoluted than simple writing, but your article probably won’t be any less comprehensible than most other scientific journal articles.

You can read the rest of the tips in his Science Careers article.

But in all seriousness, from someone from outside the academic community who still has to read scientific articles, please don't follow this advice, tongue-in-cheek though it may be. I really don't understand why science (and yes, that include mathematics and statistics) can't be written in a more natural and easy-to-read style. It's not as though a more literary style necessarily comes at the expense of clarity and accuracy.

If you've ever read any of Isaac Asimov's non-fiction popular science books, you'll know what I mean. I devoured his books as a teenager, and despite having no background in astronomy, chemistry, ecomomics, religion or any of the other myriad topics Asimov wrote about. I learned a lot about topics I'd never got to study, and had a good read while doing so. (If you have a teenager yourself, the books still make a great read, even though the science is a bit dated now. Bill Bryson appears to have taken up the eclecticism mantle for the 21st century.) So it is possible to make esoteric topics easy to understand, and without assuming extensive background knowledge on behalf of the reader. Popular science, of course, can't get into the depth of a journal article, but even there Asimov made the effort ... and ran into familiar problems. In his 1979 autobiography he wrote, 

The trouble was that I hated writing research papers … writing a research paper is a tedious and stylized job. You cannot write as you wish; you cannot use English; you cannot have fun...

It really did spoil my fun and erased any pleasure I could have had in the dissertation. Nor did it really help. Once it was done and under consideration, one professor was reported to have said, "It reads like a mystery story." And he didn't say it with approval.

Isaac Asimov did not publish another research paper after 1953.

Science Careers: "How to Write Like a Scientist" (via @peteskomoroch)

Casino outsmarted at probability

There's a great story in The Atlantic about a man who broke the bank at an Atlantic City casino by winning $6m at Blackjack. He won without counting cards: the practice of remembering previously-played cards that allows the player's expected return to exceed 100%. (Casinos consider this practice cheating, and will ban players whose play reflects card-counting strategy.) Don Johnson's carefully-observed plays were dependent only on the cards played that hand, and so he was allowed to continue his winning streak.

And this was no mere lucky streak: Johnson had also taken home multi-million dollar winnings in other nearby casinos in the last month. He did it by exploiting the odds ... and the desperation of hard-up casinos eaget to compete for the business of (hopefully) lucrative high-rollers. By convincing casino bosses to offer him loss discounts and lenient game rules, he had tuned the tables on the house edge: with enough time, money and skill, he was guaranteed to win. 

For example, at the Trop, he was willing to play with a 20 percent discount after his losses hit $500,000, but only if the casino structured the rules of the game to shave away some of the house advantage. Johnson could calculate exactly how much of an advantage he would gain with each small adjustment in the rules of play. He won’t say what all the adjustments were in the final e-mailed agreement with the Trop, but they included playing with a hand-shuffled six-deck shoe; the right to split and double down on up to four hands at once; and a “soft 17” (the player can draw another card on a hand totaling six plus an ace, counting the ace as either a one or an 11, while the dealer must stand, counting the ace as an 11). When Johnson and the Trop finally agreed, he had whittled the house edge down to one-fourth of 1 percent, by his figuring. In effect, he was playing a 50-50 game against the house, and with the discount, he was risking only 80 cents of every dollar he played. He had to pony up $1 million of his own money to start, but, as he would say later: “You’d never lose the million. If you got to [$500,000 in losses], you would stop and take your 20 percent discount. You’d owe them only $400,000.”

Figuring the odds of a table game is fairly straighforward: in a standard Blackjack, for example, the house expects to rake in a profit of 1% of all bets laid over the long run. The key there is the long run: i.e. over millions of hands played by players of varying skill levels and strategies. When it comes to figuring the expected profit that comes from attracting a skilled high-roller, things get much trickier. Casinos have computer models for to estimate the expected wins (or risk of losses) from high rollers, incorporating not just long-run probability and expected returns, but also aspects of game theory (will he quit or continue if he gets $1,000,000 up? What about $2,000,000 down?) and even physiology (will he play differently when he gets sleepy or hungry?). In this case, with the aggressive incentives and the modified rules, it seems like Johnson had the better model: “I just think somebody missed the math when they did the numbers on it,” he said.

Read the full, fascinating story at The Atlantic, linked below.

The Atlantic: The Man Who Broke Atlantic City