Archive for category pop
Too many dogs at farmers markets?
Today’s “Gray Matter” column in the New York Times provides an exceptionally well-balanced report that casts doubt on the healthiness of food from farmers markets—read it here. What caught my eye is how the author, a professor at University of Minnesota (my alma mater), lays out a number of positive correlations (being careful not to conclude causation) between farmers markets and various food-borne illnesses, including one attributed to the ‘droppings’ from dogs and the like. But the thing I most admire is him admitting to “a number of dogs that did not bark”, i.e., a number of outbreaks that did not show a statistically significant connection to farmers markets.
This suggestion of possible health issues with farmers markets is heavily hedged—very possibly it will not be borne out by subsequent research. Nevertheless it would only be prudent to thoroughly wash locally grown and sold produce.
Sine illusion makes peaks and valleys on graphs look overly variable
An article in the latest Journal of Computational and Graphical Statistics (JCGS, Vol 24, Num 4, Dec 2015, p1170)) alerted me to a fascinating misperception called the “sine illusion” that causes misinterpretation of trends in variability. See it nicely illustrated here by vision researcher Micheal Bach. The JGCS, Susan VanderPlas and Heike Hofmann, detail “Signs of Sine Illusion—Why We Need to Care” and provide methods to counteract its misleading effects.
If you see a scatter plot that goes up and down with seemingly large scatter at the bends, get out a ruler to get the true perspective. That is my take home message for those like me who like to be accurate in their assessments of data.
“The illusion is explained in terms of a perceptual compromise between the vertical extent and the greater overall dimensions of the section at the turn of the sine-wave figure.”
– RH Day and EJ Stecher, “Sine of an illusion,” Perception, 20; 1991, 49–55.
College textbooks up over 1000 percent since ’77
Bernie Sanders say it’s time to make college tuition free. That would really be radical. A more attainable goal is to make textbooks more affordable. According to an NBC story posted just prior to the current school year, college textbook prices have risen 1,041 percent since 1977, now amounting to over $1200 per student per year. My high school classmate Mark Perry, Professor of Economics at University of Michigan, warns that:
“College textbook prices are increasing way more than parents’ ability to pay for them.”
This tide of expenses for books has been slowed somewhat by the advent of rentals, e.g., $34 for one semester versus $157 to buy Montgomery’s 8th Edition of Design and Analysis of Experiments.
Another way to save that no one dreamed of in ’77 is by buying an e-textbook—Montgomery’s DAOE book costing only $67 in this format.
However, the big breakthrough in reducing the cost of college comes from the University of Minnesota’s Open Textbook Network (OTN), which began offering textbooks for free three years ago. Students over this period saved an estimated 1.5 million dollars, primarily over the past year.*
Professor Gary Oehlert of U Mn School of Statistics—a long-time advisor to Stat-Ease and author of A First Course in Design and Analysis of Experiments**—provides this endorsement of this worthy initiative by my alma mater: “There are several other similar open textbook depositories (OpenStax, etc), but OTN was one of the first to have reviews for the books as well as perhaps being the only one to have a support model for obtaining serious reviews of the books. It also has a broader range of texts than one might anticipate, with math books ranging from high school level through some fairly advanced topics.”
Powerful forces from for-profit publishers and authors who prefer being paid for their hard labor will naturally restrict the spread of free books. Even so, the OTN will certainly put a damper on the rampant inflation of the cost of texts. That will be a big relief for hard-pressed students and their parents.
*Source: “One for the Books”, Minnesota Alumni magazine, Winter 2016, p.12.
**Freely available here under Creative Commons license
Merry DXmas!
Design-Expert software produced this graphic with some wizardry by our Consultant Wayne Adams. Amazing!
Happy holidays!
Technology advanced beyond any hope for healthy curiosity
I am watching the Syfy’s series “Childhood’s End” this week. It is based on a science fiction novel by British author Arthur C. Clarke, one of my favorites growing up. One of the main characters is a very bright boy who at the end of the premier episode last night becomes an astrophysicist, despite this scientific profession being made entirely superfluous by the advanced technology of the alien Overlords.
This morning Robert Scherrer, the chairman of the department of physics and astronomy at Vanderbilt University, lamented in an editorial* for Wall Street Journal that children no longer have any reason to be interested in science, mainly because most of our household gadgets fall into the category of magic—alluding to Clarke’s observation that “any sufficiently advanced technology is indistinguishable from magic.”
“The world’s now placid, featureless, and culturally dead: nothing really new has been created since the Overlords came. The reason’s obvious. There’s nothing left to struggle for, and there are too many distractions and entertainments.”
― Arthur C. Clarke, Childhood’s End
Are you a super-recognizer?
Every now and then I see someone in an airport or other public place who looks very familiar. Now and then I’ve actually walked up to someone and greeted them by name and gotten a blank, off-putting look in return. That is embarrassing! However, I feel vindicated today after taking this 5 minute web test for facial recognition and passing it with a grade (11 out of 15) that makes me a potential “super recognizer.” 🙂 The researchers at University of Greenwich asked me to follow up by taking a 45 minute test to verify my superior abilities, but I am going to quit while I’m ahead.
If you flunk this facial recognition test, you suffer from “prosopagnosia”—that would not be good because it indicates a poorly developed “fusiform” in the back of your brain. 🙁
For those who do qualify in the UG web quiz and take the longer test, the payoff could be a job with the crack team of super-recognizers at Scotland Yard. Read about them in this fascinating National Geographic post with the Gory Details on “Face Finding Superpower for Fighting Crime”.
Fewer kids, more pets—what this world is coming to
Posted by mark in Consumer behavior, pop on August 28, 2015
NBC’s Today show posted this album yesterday of an Australian dog named Humphrey posing as a newborn baby. Unbelievable! This is what the world is coming to—far fewer children and many more animals being welcomed to families.
The latest issue of Bloomberg Businessweek tells this story of a German pet store with a quarter of a million animals—the world’s biggest—to meet the ever-growing demand of empty nesters. I cannot decide what fascinates me more, the video of 32 weird animals for sale, or the “They Never Talk Back” graphic showing how many countries everywhere have increased per capita spending on pets. The United States leads the way with an arrow point well past $120 per person spent on their loved ones, that is, household animals.
“After food, clothing and medicine, the fourth item is cosmetics and the fifth is pets. That’s serious.”
–Pope Francis
Achieving a good group photo in more than a blink of an eye
Posted by mark in pop, Uncategorized on August 16, 2015
This summer has featured a number of occasions where I got roped into a group photo, always enduring an annoying number of “just one more” shots. With this in mind, a retrospective in September’s Popular Science on the 25th anniversary of the Ig Nobel awards caught my eye by calling out the 2006 Mathematics award. This honor went to two Australian researchers who calculated that, for group photos of 20 or fewer people, you must divide the count by three and take that many photos to ensure that everyone’s eyes will be open.
Check out what to do if there are more than 20 in your group, noting that things become hopeless beyond a count of 50, and the underlying statistical calculations detailed in “Blink-free Photos, Guaranteed,” Nic Svenson, Australasian Science, August 2006, p48.
Upon accepting the award for frivolous research, the lead scientist, physicist Piers Barnes, said that
“We are proud to have made a gross simplification of complex physiological and psychological factors backed up with no empirical data. Like many other theories, if enough assumptions are made, we are confident that our expression holds.”
(Source: This phys.org press release.)
For count of calories it is nary the area of the Oreo but the thickness
In a new twist on sandwich cookies, the manufacturer of Oreo brand cookies, Chicago-area based Mondelez International, now offers a thin version with a 12.5% reduction in calories per serving. (From what I gather off the internet a “serving” seems to vary from 2 to 4 cookies, depending on the thickness, I suppose. For example, I would not advise eating four Mega Stuf Oreos in one sitting.)
The Detroit Free Press gives the 7.5 mm thick Oreo Thins two thumbs up in this July 6 review. Unfortunately the reduction in filling from the 12.5 mm thick regular cookie closes out as a practical matter the option for splitting them apart, which normally about half of Oreo cookie-eaters do, according to Mondelez.
These thin confections are likened by the Oreo maker to crepes, perhaps to be eaten only at fancy teas in the mid-afternoon by proper ladies and gentlemen. To me that is a deal breaker. I plan to eschew the Thins in favor of the Mega Stuf, which according to this “implusive” blogger who will eat “anything edible no matter how strange” contains 52.5% more filling than Double Stuf.
Come to think of it, the food scientists at Mondelez really out to come up with an Oreo that is comprised only of the crème filling—saving us the trouble of having to twist them apart.
Pyrex—a miracle of material science—hits the century mark
A few years ago I dropped my cell phone and, to my great surprise, broke the Corning® Gorilla® glass display. This incident illustrates how far our expectations have come for what originally was an extremely fragile material. Tough glass is a very recent development that still falls a bit short—even the newest Gorilla Glass 4 survives drops only 80% of the time according to Corning. But give these material scientists a little more time. They are sure to do even better at making glass truly unbreakable and far more flexible to boot.
Resistance to temperature, on the other hand, is now a given with glass, in particular the brand Pyrex® introduced in 1915 by Corning. They quit manufacturing Pyrex in 1998 but you can still buy it, albeit in a cheaper form made from soda-lime rather than borosilicate.*
For the whole story, see Pyrex at 100 from the May 18th issue of Chemical and Engineering News (C&EN).
*(You are advised to read these shattering details from The American Ceramic Society on the consequences of going to the less-costly Pyrex.)