I find it ironic that we are in serious risk of running out of the 2nd most abundant element in the universe. Read on. It’s a fairly realistic concern. Helium is very light, and is ultimately unbound to Earth gravitationally. So once it escapes into the atmosphere, helium will diffuse off into space. Space, being very large, is an extremely inconvenient place to recover an escaping gas.
No, Wikipedia’s editors aren’t guilty of bias (this time). It’s the featured article for today! Check it out! Of course if you read talk pages for long enough you will discover that Wikipedia does have a bias towards America, the English language and English-speaking countries, hurricanes (at least one was a tropical storm, though), and antarctic explorers. (Note: tongue planted firmly in cheek.)
NPR talks to Dan Myers of Notre Dame University about the shortest possible game of Monopoly he and his son designed. It’s extremely unlikely. One player quickly moves around the board to buy Boarwalk and Park Place, then the other player draws a chance card to go to one of those properties with four houses on it and can’t afford the rent. Two turns per player.
Next project is reported to be finding the shortest possible game of Risk. It kind of makes me want to analyze Settlers of Catan or something.
http://www.npr.org/templates/story/story.php?storyId=127575676
May 16th is recognized as the anniversary of the laser. Lasers are pretty cool–I’ve had the opportunity to work on the back-end to some laser systems for studying atmospheric aerosols. Which is a bit like saying I’ve had the chance to live in the same state with John Mellencamp, except I like lasers way more than I like John Mellencamp. Anyway. On with the list of cool laser links:
Steven Strogatz is proposing that Bayes Theorem is too complicated for people, and we should switch to something more intuitive in this New York Times Opinion piece. I’m not exactly endlessly proficient with Bayes Theorem, but I think his alternative method for approaching problems of conditional probability amounts to a reworking of Bayes theorem. Check out the Wikipedia article. With the information he gives you for the mammogram problem, you should be able to get the correct solution by plugging in numbers to the “simple statement” of the theorem. He even gives you the correct answer, so you can check yourself.
Bad Science writer Ben Goldacre wrote about how “Guns don’t kill people, puppies do,” where he points out some ways in which the probabilities of things can be a bit confusing. An extremely common example, which was messed up by a British newspaper, is the probability of multiple people (siblings in this case) sharing a birthday.
Like he says, the trick is that it doesn’t matter when the first child was born, only that the next two were born on the same day. This is a trivial case in which the binomial coefficient simply cancels out the leading 1/365. In general, though, you can use the binomial coefficient (sometimes called “n choose k”) to calculate probabilities where you can get the same result in multiple ways.
So if you’re guessing the suit of a hidden playing card, you have a 1/4 chance of guessing correctly. If you guess for 10 different cards and get 5 correct, you might be tempted to say your feat was as likely as 
, and that you might have psychic powers. What you’re missing, though, is the number of ways you could have guessed correctly, 
, which means the probability of correctly guessing half the cards was 0.058. You could still be psychic, but now it doesn’t seem quite as likely.
Tune in later for a crash-course introduction to P-values and hypothesis testing, so we can conclude with more certainty one way or the other on your psychic abilities.
I’d be remiss in my duties if I failed to post a link to Jorge Cham’s recent PHD comic about the use of polls and statistics in the news media. He hits the proverbial nail on its proverbial head. Also, if you haven’t read the comic before, it will be an amusing and whimsical dark comedy to those who have not experienced grad school, and a humorously whimsical reflection of the dark, bleak reality that is graduate school for those who have. Has anyone seen my thesis topic?
There’s a collection of interesting statistics collected from the Okcupid online dating site. They’ve tracked the response rate to messages containing certain words or combinations of words. To sum up the results, using correct English grammar and spelling as well as unusual words to set a message apart from others really help. Complementing a woman on her looks doesn’t. I actually met my girlfriend online, and she says that most people said something about her breasts. I asked her about her favorite place to get coffee. Guess I won on that one. If you must know, though, she’s fond of Dewy’s, while I prefer Phoenix.
Anyway, the other stat that was emphasized by Sean “The Guy Who Wrote My GR Textbook” Carroll, is that mentioning atheism improved response rate more than Christianity. Mentioning god without a proper name reduced the response rate from the average. So add that to your list of reasons why atheism is a good way to start conversations.
First of all, a hat-tip to Skepchick. Second, I have not laughed this hard reading an article from Nature in, well, ever. Jeff Lozier of the University of Illinois at Urbana-Champaign has taken a very creative and humorous approach to demonstrating the weakness of an ecological analysis technique.
The idea seems to be that if you know the environments a particular species lives in now, you can make a pretty good guess at the regions it has lived in in the past and will live in the future after the effects of climate change take hold. His argument is that the technique is only as good as the data that go into producing the slick graphics that make it so popular. Lozier’s critique is that species missidentification can lead to unreliable conclusions. From the Nature.com article:
Such errors can be hard to spot, because even if all the data are all highly dubious, a model based on them can still give a plausible-looking result, as Lozier and his colleagues found when they analysed sightings recorded by the Bigfoot Field Researchers Organization.
The reported sightings imply that the wooded and mountainous areas of California, Oregon and Washington teem with sasquatch at present. Warm the climate, and, like many other species, it will probably move north and uphill.
“It’s a perfect commentary on the potential problems of this approach,” says Lozier. “Plus, it’s a sasquatch paper.”
Unlikely as it sounds, Lozier’s paper scooped work by another group. “We were trying to do the same thing for the yeti,” says ecologist Carsten Rahbek of the University of Copenhagen. Like Lozier, he wanted to show that models could turn dubious data into plausible-looking predictions.
When I got to the quote, “We were trying to do the samet hing for the yeti,” I nearly spit coffee all over my computer.
If you’re a huge nerd, you’ve probably at least seen Wolfram Alpha. At least once a week or so I stop to play with it to see if I can get it to do anything cool. So it can tell you where most of the worlds Portuguese speakers live and give you a side-by-side comparison of the population, land area, and GDP of South Africa and Lesotho. Both of those are extremely cool, but this morning I found a new one. Just in case you ever wanted to know what would happen if you rolled two 12-sided dice (since 3rd Ed. D&D will probably never give you the opportunity) it will now give you the mean value and a histogram! It works for an number of dice with any number of sides. Even the mysteriously fair 5-sider. There seems to have been a large gaming-related “expansion” or something to the site, because it will also tell you the probability of a full house.
This kind of thing could probably entertain me for hours.