Archive for December, 2012

Glass-shattering interaction of factors

Last week (12/21) the Today Show broadcasted an alarming demonstration of Pyrex glass exploding after being subjected to certain combinations of conditions.  See NBC News’ detailing here .  As reported in this American Ceramic Society Bulletin , some scientists believe that changes to the material (replacing borosilicate with soda lime silicate) weakened the glass.  However, makers of Pyrex disagree vehemently with these conclusions—see their side of the story here.

It turns out that hot Pyrex pans set directly on a wet or cool surface, such as a granite counter-top, undergo a sudden temperature change that produces some risk of it shattering.  That strikes close to home for me, having re-done our kitchen (as is the style nowadays) with granite.  Fortunately, being accustomed to plastic (Formica) countertops, I always put down cloth potholders before setting down the hot Pyrex pan.  The take-home message is being careful not to subject Pyrex to rapid increases or decreases in temperature.  See this site for safety instructions.

PS. On a lighter note (literally: too much sun) regarding heat and silica (main constituent of sand) see this New York Times news making it official that the hottest temperature ever recorded is 134 degrees F in Death Valley.  They are pyre Rex.

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Correlation of price of wine with the fineness of its taste–an absurd example

A toast to 2013Behavioral Economics Professor Dan Ariely of Duke University provides an illuminating and humorous example of irrational valuation in his advice column today for Wall Street Journal. It seems that this Christmas holiday weekend may be ruined for a couple who took advantage of a buy-one-get-one-free (BOGO) sale on a fine wine. Actually they paid $17 for one bottle and a nickel ($0.05) for the other. They asked Professor Ariely to help them escape a terrible dilemma: For the holiday party would it be OK to bring the cheap wine? Ha ha!

I hope that for the coming year all of you readers of StatsMadeEasy do not get hung up spurious issues like this relating to correlation and causation or any other statistical kerfuffles. Happy Holidays and New Year!

PS. I leave you with this toast to 2013–a picture taken last week during my tour of a winery in the Colchagua Valley south of Santiago, Chile. Cheers!

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Strange times: Ice forming in unlikely places and melting where it shouldn’t

My flight yesterday from Minneapolis to Santiago got held up for de-icing.  Being so near to the year-end solstice, the change in seasons from Minnesota to Chile could not be more dramatic—a swing of 45 degrees in solar angle relative to the ecliptic plan.  So it’s out of snow (storming today back home) and into 80+ degrees and pure sun. : )

Things are wackier than I’d thought in regard to where one might expect to find ice nowadays.  For example, who would have thought that water could freeze on Mercury?  But that’s what NASA recently reported based on a shout out from their spacecraft Messenger, which detected polar hydrogen via neutron spectroscopy.  See the details here.  I enjoyed the quip by Sean C. Solomon, the principal investigator for Messenger, about there being enough ice to encase Washington, D.C., in a frozen block two and a half miles deep.*  That might be what’s needed to cool down all the rhetoric about the fiscal cliff.  😉

Meanwhile the worries about the warming climate melting Earth’s icecaps just keep coming on.  Concerned about contrails contributing to the greenhouse effect, the Washington Post is now demanding the Santa’s sleigh be grounded.  Read this 12/4/12 blog and weep. : (

*On Closest Planet to the Sun, NASA Finds Lots of Ice, 11/29/12

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The amazing persistence of biased scientific results—Popeye’s spinach found fraudulent

I recently completed a series of webinars on using graphical diagnostics to deal with bad experimental data.*  The first thing I focused on was avoidance of confirmation bias – hearing what you want to hear, for example in the persistence of the possibilities of cold fusion.  See more cases of confirmation bias in this detailing by Peter Bowditch in Australasian Science.

I came across another interesting example of the persistence of wished-for results in a review** of Samuel Arbesman’s new book on The Half-Life of Facts.  It turns out that spinach really does not delivery the amount of iron that my mother always believed would make it worth us eating this horrible food.  She was a child of the 1930’s, at which time it was widely believed that the edible (?) plant contained 35 milligrams of iron, a tremendous concentration, per serving.  However, the actual value is 3.5 mg—the chemist who first analyzed it misplaced the decimal point when transcribing the data from his notebook in 1870!  In 1937 this error was finally corrected, but my mom never got the memo, unfortunately for me and my six younger siblings. ; )

*“Real-Life DOE” presentation, posted here

** The Scientific Blind Spot by David A. Shaywitz in the 11/19/12 issue of Wall Street Journal

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