Posts Tagged history
Fascination for pendulums piqued by Foucault’s in France
Posted by mark in science, Uncategorized on June 26, 2018
Earlier this month I visited the Pantheon in Paris where I observed this attendant recalibrating Foucault’s pendulum.
This French scientist’s elegant scientific demonstration of earth’s rotation has delighted observers like me since 1851. For more on this story read this Ask Smithsonian blog. Unfortunately, one morning in 1998, the cable on the 52-foot long pendulum at Smithsonian’s National Museum of Natural History (originally History and Technology when opened in 1964) snapped, nearly ‘clocking’ a staffer with its wayward 240-pound brass bob. This Foucault device being unAmerican and dangerous, it was removed in favor of the Star-Spangled Banner Preservation Project, thus eliminated a favored place for folks to gather.
By the way, I am now reading The Discoverers by The Librarian of Congress, Daniel Boorstin—the first in his wonderful Knowledge Trilogy. There, coincidentally, I learned that Galileo—only 19-years old at the time (1583) and bored by a church service in Pisa—became distracted by the swinging of a chandelier. By timing his pulse, he observed the time of a pendulum being independent of its arc length—an important discovery of a property called isochronism. This simple discovery, as pointed out by Boorstin, began a new age where science developed from observation and measurement rather than pure speculation.
The hero of zero
Posted by mark in Basic stats & math, history on October 9, 2017
Breaking news about nothing: Dating done with the Oxford Radiocarbon Accelerator Unit now puts the invention of the number zero 500 years earlier than previously believed. As explained in this post by The Guardian, the hero of zero is Indian mathematician Brahmagupta who worked out this pivotal number in 628 AD. Isn’t that something?
The development of zero in mathematics underpins an incredible range of further work, including the notion of infinity, the modern notion of the vacuum in quantum physics, and some of the deepest questions in cosmology of how the Universe arose – and how it might disappear from existence in some unimaginable future scenario.
– Hannah Devlin,
A knotty problem—how to keep track of stuff without computers or even pen and paper
Posted by mark in history, Uncategorized on January 3, 2016
The New York Times reports today on the recent discovery of several knotted string records, called khipus, that ancient Incas used to record things such as the colorful potatoes I photographed at a Peruvian market. From what I saw on my travels there—see this blog on Incan agriculture experiments, a great deal of food must have been produced and stored.
Based on this Times picture I suspect these “mops that have seen better days”, as George Gheverghese Joseph, a mathematics historian at the University of Manchester, U.K., put it, must be a bit easier to untangle than Christmas lights. But then there remains the problem of deciphering them.
Thus far researchers have picked up on mathematical aspects of the khipus. However, the latest trove of colored strings provides a chance at figuring out the Incan scheme for identifying what was being counted. Here is where database capability and statistical methodology comes in handy.
I amazes me how all of the technology we now have at our disposable is challenged by methods developed 600 or so years ago. Hats off to Incan ‘thinken!
“Many now think that although khipu probably began as accounting tools, they had evolved into a writing system—a kind of three-dimensional binary code, unlike any other on Earth—by the time the Spanish arrived.”
— Cracking the Khipu Code Science magazine.
Statistics for good (per year-long celebration) or bad (as many still feel)
“As with a knife in a surgeon’s hands, it can save a life, but it could also kill someone, in the hands of a crook.”
— Sastry Pantula, Dean of the College of Science, Oregon State University
This quote caught my eye in yesterday’s Wall Street Journal article on “About 88% Through Year, 100% of Statisticians Find Field ‘Sexy’”—a recap of Statistics2013, which pays homage to the 300th anniversary of Jacob Bernoulli’s landmark book The Art of Conjecturing.*
My interest in statistics stems from a belief that one should live by what you see, not what supposedly should be. In other words, let the data speak. I have little patience for speculation based only on personal opinion, unless it comes from one who clearly possesses great subject matter knowledge—even then I would like to see peer-reviewed research supporting the contentions. The converse of this is being greatly off-put by people who obviously do not know what they are talking about using statistics as a weapon. This is crooked (as noted by Prof Pantula).
But never mind this dark side of statistics, it’s time to celebrate them as Gianluca Massimo and his Italian friends (including students in Statistical Sciences at the University of Padua) did in this ‘bromantical’ music video.
*For a scholarly review and historical context, see “The Significance of Jacob Bernoulli’s Ars Conjectandi for the Philosophy of Probability Today” by Glenn Shafer of Rutgers University.
This baby really did explode
Posted by mark in history, Uncategorized on January 27, 2013
I’ve been blessed with another grandson, my second, who arrived just before Thanksgiving. I’ve become a bit gun-shy holding him due to his explosive colonic evacuations. Today, though, I realized that being a babysitter could be a whole lot worse. See what I mean by reading this New York Times obituary for nuclear scientist Donald Hornig.
In a small shed at the top of a 100-foot-tall steel tower deep in the New Mexico desert, Donald Hornig sat next to the world’s first atomic bomb in the late evening of July 15, 1945, reading a book of humorous essays. A storm raged, and he shuddered at each lightning flash.
The amazing persistence of biased scientific results—Popeye’s spinach found fraudulent
Posted by mark in science, Uncategorized on December 5, 2012
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
Where the radix point becomes a comma
Posted by mark in Basic stats & math on April 23, 2012
Prompted by an ever-growing flow of statistical questions from overseas, Stat-Ease Consultant Wayne Adams, recently circulated this Wikipedia link that provides a breakdown on countries using a decimal point versus a comma for the radix point—the separator of the integer part from the fractional side of a number.
For more background on decimal styles over time and place see this Science Editor article by Amelia Williamson. It credits Scottish mathematician John Napier* for being the first to use a period. However, it seems that he wavered later by using a comma, thus setting the stage for this being an alternative. Given the use of commas to separate thousands from millions and millions from billions and so on, numbers can be misinterpreted by several orders of magnitude very easily if you do not keep a sharp eye on the source.
So, all you math & stats boffins—watch it!
*As detailed in this 2009 blog I first learned of this fellow from seeing his bones on display at IBM’s Watson Research Center in New York.
Tasty tidbits gleaned by a news-starved junky for stats trivia
Posted by mark in history, Uncategorized on June 10, 2010
The June 10th “Views” section of the International Herald Tribune (the global edition of New York Times) offered a few choice bits for me to savor after nearly two weeks traveling abroad without an American newspaper.
- A pie chart reporting on a June 1-7 telephone survey by Stanford University of 1000 American adults asking their opinion on belief in global warming. A pie chart illustrated that about 75% do believe in global warming, 20% do not, and 5% “don’t believe in pie charts”. I suspect that the author of this editorial, Jon A. Krosnick – a professor of communications at Stanford, meant this last bit of the chart to represent those who are undecided, but the graphic designers (Fogleson-Lubliner) figured they’d have some fun.
- Olivia Judson’s comments on “Galton’s legacy” note that this preeminent British statistician once published a comment in Nature (June 25, 1885 “Measure of Fidget”) that correlated boredom by how the audience squirmed during particularly wearisome presentations. I wish I would’ve thought of this “amusing way of passing an otherwise dull” lecture before attending two statistical conferences over the last several weeks. Based on this 2005 assessment of “Nodding and napping in medical lectures”, the more things change the more they stay the same, at least so far as presentations are concerned. The only difference is cost. For example, the authors figure that at a typical 1 hour talk to 100 high-powered professionals, say master statisticians, perhaps as much as $20,000 goes up in snores.
“Nodding was common, but whether in agreement with the speaker or in reverie remains undetermined.”
— Kenneth Rockwood (Dalhousie University), Christopher J. Patterson, McMaster University, David B. Hogan (University of Calgary)
Bonferroni of Bergamo
Posted by mark in Basic stats & math, history, Uncategorized on June 6, 2010
Bonferroni corrected
Uncorrected (random results)
I enjoyed a fine afternoon in the old Citta Alta of Bergamo in northern Italy – a city in the sky that the Venetians, at the height of their power as the “most serene republic,” walled off as their western-most outpost in the 17 century.
In statistical circles this town is most notable for being the birthplace of Carlo Emilio Bonferroni. You may have heard of the “Bonferroni Correction” – a method that addresses the problem of multiple comparisons.
For example, when I worked for General Mills the head of quality control in Minneapolis would mix up a barrel of flour and split it into 10 samples, carefully sealed in air-tight containers, for each of the mills to test in triplicate for moisture. At this time I had just learned how to do the t-test for comparing two means. Fortunately for the various QC supervisors, no one asked me to analyze the results, because I would have simply taken the highest moisture value and compared it to the lowest one. Given that there are 45 possible pair-wise comparisons (10*9/2), this biased selection (high versus low) is likely to produce a result that tests significant at the 0.05 level (1 out of 20).
This is a sadistical statistical scheme for a Machiavellian manager because of the intimidating false positives (Type I error). In the simulation pictured, using the random number generator in Design-Expert® software (based on a nominal value of 100), you can see how, with the significance threshold set at 0.05 for the least-significant-difference (LSD) bars (derived from t-testing), the supervisors of Mills 4 and 7 appear to be definitely discrepant. (Click on the graphic to expand the view.) Shame on them! Chances are that the next month’s inter-laboratory collaborative testing would cause others to be blamed for random variation.
In the second graph I used a 0.005 significance level – 1/10th as much per the Bonferroni Correction. That produces a more sensible picture — all the LSD bars overlap, so no one can be fingered for being out of line.
By the way, the overall F-test on this data set produces a p value of 0.63 – not significant.
Since Bonferroni’s death a half-century ago in 1960, much more sophisticated procedures have been developed to correct for multiple comparisons. Nevertheless, by any measure of comparative value, Bergamo can consider this native son as one of those who significantly stood above most others in terms of his contributions to the world.
Stat-Ease Corporation celebrates 25 years in business
Posted by mark in history, Uncategorized on May 16, 2010
My business partner Pat Whitcomb started up Stat-Ease as a business entity in 1982,* but he did not incorporate it until June of 1985. So that brings us to 25 years as a Corporation this coming month. This is quite an achievement for a software publisher – not many remain since 1985, I’ll wager, especially ones so specialized as us. That’s our saving grace, I figure – sticking to a niche like a clam in a wave-beaten hollow.
According to this report on U.S. Small Business Administration Office of Advocacy statistics from September 2009, only half of all startups survive five years. This correlates with a decay curve posted by Scott Shanem Professor of Entrepreneurial Studies at Case Western Reserve University, which shows that only about a quarter of companies remain alive after ten years.
I’d say we’ve done very well to make it this far. Having weathered the recent economic downturn in good shape, I feel positive about continuing on for at least a few years more. 😉
PS. If you’re interested to learn more about us, check out this history of Stat-Ease.
*The year the word “internet” was used for the first time according to this timeline. Check out these photos from the 1980’s by the Computer History Museum, especially the Osborne “portable” (24 pounds!) PC with a screen that looks about the size of today’s internet-enabled smart phones.