For a healthy 2026, resolve to lengthen your walks
I love to walk, cross-country ski or bike. It invigorates me physically and mentally. Thus, I found it interesting that, according to this October 2025 study published in the Annals of Internal Medicine, longer walks might provide more benefits than shorter ones at the same step counts.
But be careful drawing this conclusion because the results show correlation, not causation. Furthermore, the study focused on suboptimally active adults with step counts at 8000 or less per day. I am satisfied only by achieving at least 10,000 steps in a day.
I think a good new year’s resolution is to increase your step count per day by taking longer walks. However, on days when you cannot spare much time, try taking a number of short walks and do so a bit faster.
If you also like to walk and/or are resolved to do so this new year of 2026, see today’s post by RTÉ—the website of Raidió Teilifís Éireann, Ireland’s National Public Service Media—on 5 ways to make your daily walk more beneficial in 2026.
Get a move on!
Shocking outcome from purple potato
Along the lines of the video below, my oldest grandson Archer came up with some very interesting results from his 8th grade science project: Magic Molly purple potatoes produce more electricity gram-for-gram than Yukon Gold or Red Norland; 10.6 vs 7.9 vs 7.6 millivolts; respectively. All the potatoes came fresh from his family’s garden. He chained 3 potatoes together for each voltage measurement, thus dampening out potato-to-potato variation.
Archer also tested a sweet ‘potato’, which did very poorly on his voltage measurement (5.9 mV)—perhaps not surprisingly, it not actually being a potato.*
Archer had hypothesized that “all of the potatoes will create the same amount of volts because the phosphoric acid in the potatoes that gives them power has no color, and color is the difference between most potatoes; therefore, there shouldn’t be a difference in voltage output.” However, given his sample size being only one per variety of potato, further testing would be needed to disprove his hypothesis with adequate statistical power (e.g., p<0.05).
I advise starting with at least 4 of each potato variety and doing the testing via a randomized plan, that is a proper design of experiment. It would also be interesting to do add other factors, such as boiled versus raw and extend the test out for some days to see if the voltage drops.**
Who knew such an unglamorous vegetable (“starchy tubers”, ha ha) could be so much fun?
* See Carnegie Museum of Natural History’s explanation: Potatoes, Sweet Potatoes, and Yams: What’s the Difference?
** For clues on this, see The Not So Humble Boiled Potato! by Samantha Parker, Museum Educator, National Electronics Museum, 2020.
Response surface methods hit the spot for optimizing projectile hurling siege engines
Posted by mark in design of experiments, physics on November 12, 2025
A few weeks ago, Professor Ernst Ferg, Associate Professor – Physical Chemistry at South Africa’s Nelson Mandela University bounced (pun intended) some questions off me about deploying response surface methods (methods) on a catapult operated for education purposes by three of his students. I built up power and developed insights on relative performance of the artillerists by rebuilding his results into a fully replicated blocked design.
Now, aided by Stat-Ease software for DOE, you can see surprisingly close agreement on the central composite design’s center-point set-up (red dots) for the catapult (the reason for this soon to be revealed).
Pooling all the results into one model produced a very impressive 3D graph of distance as a function of the two biggest factors—release angle (A) and cup elevation (B).
Being impressed by Ernst’s initiative to teach his students RSM, I asked him to send me pictures of them operating the catapult. Ernst replied, “LoL, I am approaching this very much in the digital way of things: I made them use Virtual Catapult© from SigmaZone.”
It turns out that Ernst learned about the Virtual Catapult (free!) from Tom Keenan—one of four DOE educators who shared their experiences Teaching Design of Experiments in Higher Education. Tom said that “I love the way that it shoots the ball but doesn’t give you the measurement. It comes to rest next to a tape measure that the students have to read.”
Tom also likes the way that the Sigma Zone simulation incorporates some variability, thus every student gets slightly differing results. He collects the results in blocks and does an analysis similar to what I did for Ernst—being watchful of students who deviate from the others.
Fun!
PS: After gaining possession of a South Dakota Mines trebuchet from Professor Dave Dixon (one of the four panelists), I enlisted my son Hank to run an RSM optimization on this more efficient counterweight-driven cousin of the catapult (powered by torsion). We ran a Box-Behnken design, which simplified the operation to only 3 levels of each factor (versus 5 levels required for a central composite design). Ultimately, we worked out a set up that would shoot a salt-weighted raquetball over our backyard bush into a bucket on the upper level of our play fort. Empowering! For all the details on our trebuchet experiment (and pictures), see Messing With Medieval Missile Machines (Part 2).
Fresh-made mac and cheese—the ultimate comfort food
Posted by mark in food science, Uncategorized on November 5, 2025
The New York Times Wirecutter team came out with a report in early September that rated Kraft Mac & Cheese Original their favorite out of the 19 boxed options tested, saying that its “buttery and silky-smooth sauce clings to each soft noodle.” If that doesn’t make your mouth water for a fresh hot bowl of gooey orange pasta, nothing will. But as writer Ciara Murray Jordan reveals in her video recap of the Wirecutter test, even a comfort food like mac and cheese becomes nauseating when binged.
Two decades ago, I ran statistically design of experiment (DOE) on Kraft Mac & Cheese Original versus their recently released Easy Mac—a more convenient, single-serve microwavable variation on their traditional stovetop, boxed brand. My goal was to see how two experimental recipes for canned mac and cheese from a Stat-Ease client (confidential) performed against King Kraft.
My wife Karen cooked up the four competing foods and presented them in random order for blind taste testing by me, my three daughters—Emily (age 21 at the time), Carrie (16), Katie (14) and three of her friends—seven in all. We rated the mac and cheese on a scale of 1 to 5—higher the better.
As you can see from the one-factor plot produced by Stat-Ease software, my client made great improvements via application of DOE on the recipe and processing of their canned product. (The numbers by some points indicate multiple results at that rating.)
Unfortunately, as you can see by the least-significant-difference bars (essentially a 95% confidence interval), this project failed to meet its goal—a canned mac and cheese just cannot best a fresh made one. As seen in the scatter plot by taster, Kraft (in one form or the other–the red and blue points) consistently came out on top.
So it goes for researchers and process developers—you win some and lose some (more of the latter). However, I did feel good seeing the original recipe (green points) rated so low by all the tasters and their far greater liking for the DOE-enhanced product.
By the way, I am now quite hungry for mac and cheese.
You too?
Today’s Major League Baseball batters all hit below average
Posted by mark in sports, Uncategorized on October 24, 2025
This headline gets your attention if you like statistics. It makes no sense without the context: See Baseball Reference’s report on batting average (BA) by year. In 2000 MLB batters averaged .270 (expressed as “two seventy”), but after years of decline they bottomed out at .245 (two forty-five) or so. This reflects a more analytical approach to hitting that disrespects batting average as a metric, it being likened to counting the number of bills in your wallet but not amount of money.
Nowadays MLB teams value players who excel at on-base-plus-slugging (OPS). This mashup of stats creates percentages over well over 100 (“one thousand” in baseball terms) for the utmost elite players—in 2025 only Aaron Judge of the New York Yankees and Shohei Ohtani of the Los Angeles Dodgers. MLB adopted OPS in 1984 after Pete Palmer introduced it in the pioneering book (co-authored by John Thorn) The Hidden Game of Baseball, A Revolutionary Approach to Baseball and Statistics.
OPS combines simplicity with reasonable accuracy and I think that is why it is popular.
– Jim Thorn, Why OPS Works, Fall 2019 Baseball Research Journal, Society for American Baseball Research (SABR)
I’ve been a fan of baseball since 1961 when the Washington Senators moved to the Twin Cities to become the Minnesota Twins. I was 8 years old then. My grandpa had been following the Minneapolis Millers since the late 19th century as a young boy. He turned 8 in 1896 when his home team won their first Western League pennant.
Grandpa was an accountant, so, naturally he collected statistics on every Twins game—carefully ruling out rows and columns for the 9 batters and 9 innings and noting each players batting average. Because of that I am a holdout for appreciating players with high batting averages. I would rather see more hits and the strikeouts that come along with trying to hit a home run at every at bat.
On the other hand, I do not doubt that a lot of people will tune in tonight for Game 1 of the World Series to see if Shohei Ohtani lives up to his “Shotime” nickname by blasting at least one home run, if not several as he did in Game 4 of the National League Championship Series. American League fans like me will be rooting for George Springer (3rd in MLB for 2025 OPS at .959) of the Toronto Blue Jays to hit another dramatic home run like he did for in Game 7 of the AL Championship Series.
Baseball is the greatest game!
Experiment creates a reversal in time
When your boss applies maximum time-pressure by saying “I want your results yesterday,” consider lining up a couple of lasers to get the job done. Next, as demonstrated by scientists at the University of Toronto, gather up rubidium atoms and chill them to near absolute zero. Then take some shots with your lasers and take your time from the subsequent reversal. It’s all laid out by experimental evidence that a photon can spend a negative amount of time in an atom cloud.
“It took a positive amount of time, but our experiment observing that photons can make atoms seem to spend a *negative* amount of time in the excited state is up!”
– Aephraim Steinberg, a physicist at the University of Toronto
For an easier 5-minute readout from Scientific American, see this 9/30/24 post: Evidence of ‘Negative Time’ Found in Quantum Physics Experiment.
Next on the agenda for making your work easier is to capture some negative energy. Soon, thanks to advancements in physics, you will be getting jobs done yesterday with no effort whatsoever!
Optimal airline boarding strategy will never get off the ground
Posted by mark in Consumer behavior, Uncategorized on August 19, 2025
As I waited at the end of a line last week to board the Mount Washington Cog Train with my assigned-seat ticket in hand, it occurred to me that only needing a small backpack made the process far simpler than for a flight burdened with carry-on baggage. A random free-for-all process, providing priority by willingness to wait in line, served well for the 45-minute ride up and down the mountain.
It’s not nearly as simple getting luggage-laden people on board a flight. But there is a solution. In 2008, astrophysicist Jason Steffen came up with “perfect airplane boarding method.” It starts by seating window-seat passengers every other row from back to front along one side and then the same on the other side. Then repeat the process with middle seats and, finally, the aisle.
For a fun ‘Pac Man’ illustration, see this interview of Steffen by News Nation:
An experimental test of airplane boarding methods using a mock Boeing 757 airplane showed that Steffen method cuts the time in half from traditional methods going by zones. But though it would certainly save airlines a great deal of time and thus money to switch their boarding to this innovative method, none are likely to make the change due to its precise control of passenger being impractical. Elite flyers accustomed to priority boarding would be very unhappy. Furthermore, families must be broken up in the Steffen-method lineup—not good.
However, there is hope for a better way on to an airplane. As noted in the News Nation video, United Airlines adopted a simplified Steffen method called “WILMA” that boards passengers first by window, then middle and, finally, aisle. However, as laid out in this June 24, 2025 post by CNBC the airline exempts many passengers from WILMA, including those with United credit cards. Perhaps that’s why they only save 2 minutes per flight with their new boarding process. But at an estimated cost of $100 per minute the savings of $200 per flight times nearly 5,000 flights per day by United adds up to $1 million in daily savings.
Based on my experience boarding the Mount Washington Cog Train and numerous studies, a random process serves well by it being fair and fast. When American Airlines tried it in 2011 on all but those passengers with elite status, the random process shaved 20 to 25 minutes off average times. However, according to their flight attendants, it created “complete chaos in the cabin.” As you can see in this April 26 press release, American now goes by a 9-group process. Evidently saving time via free-for-all boarding cannot provide payback for the pandemonium.
Will ‘Mexican’ cane-sugared Coke prevail over corn syrupy Pepsi?
Posted by mark in food science, pop on August 5, 2025
My parents never let me drink pop (as we referred to ‘soda’ in Minnesota). But my grandma treated us to Royal Crown (RC) Cola. Sweet! RC Cola is now mostly forgotten, which narrows the choice down to Coca Cola (Coke) versus Pepsi.
I’ve been trying to work out scientifically which cola tastes better for many years without success. At age 15, my daughter Katie presented me with a blind tasting test but she went awry by confounding input factors, as I laid out in [this May 2004 Stat-Teaser article]. Since then, I’ve vacillated between Coke and Pepsi. When vacationing in Mexico, I observed that their Coke featured cane sugar versus corn syrup for the USA-bottled beverage. Being born and raised in the Corn Belt, that appealed to me—it being very exotic. So, when President Trump announced he’d gotten agreement from Coca Cola to use “REAL” cane sugar, I wondered if that would make Coke the clear winner of the cola war.
Based on a blind tasting by The New York Times’s wine critic, Eric Asimov—reported by the newspaper in early August, Pepsi prevails over USA and Mexican (cane) Coke, despite being made with high-fructose corn syrup. Unfortunately, it’s likely that Coke will ultimately win out due to consumer perceptions that create the Pepsi Paradox.
Though I am a master in business administration (MBA) and thus a proponent for good marketing, my engineering and statistical sensibilities cause me to oppose this triumph by Coke of branding over taste. If you drink colas, enlist someone to present the options—Coke (cane versus corn) versus Pepsi—in a blind taste test with the drinks provided in the same receptacles (avoiding the Katie confounding).
Let me know what you prefer.
Diverging diamond interchanges speed up traffic, but they feel weird
Posted by mark in engineering on July 3, 2025
Sarasota County, like all coastal areas in South Florida, gets jammed up by ‘snowbirds’ like my wife and I, who migrate there every winter to escape Minnesota’s painfully cold weather.
To alleviate traffic at its heaviest near the city of Sarasota, the Florida Department of Transportation (FDOT) converted the junction of Interstate-75 at University Parkway to a diverging diamond interchange (DDI)—the largest in the world at the time it was implemented in 2017. This development increased capacity by 33 percent to 80,000 vehicles per day and reduced the intersection delays by 50 percent. These improvements stem from a large reduction—over 50 percent—in the conflict points.
Soon the I-75 at Fruitville Road interchange will also be converted to a DDI by FDOT. Hundreds more are either already built or under construction across the USA. If you haven’t experienced a DDI, get ready for being disconcerted from the temporary reversal of lanes.
I hate DDI’s so much, that when forced to drive down University to pick visitors up at the Sarasota Bradenton Internation Airport, I exit I75 at Fruitville Road. But this resistance is fruitless (pun intended) due to the upcoming project by FDOT.
I also dislike roundabouts when traffic gets to the point where it becomes very difficult to break in on the flow. Sarasota County features a great number of traffic circles like this. The mix of slow senior snowbirds and aggressive Florida men aggravates the free-for-all.
All this makes route planning and timing essential when driving during Florida’s peak season. Fortunately, I enjoy challenges like this that involve multiple constraints. As the guru Sivananda Saraswati said, “the harder the struggle, the more glorious the triumph.”
Making the most from every coffee bean and doing so tastefully
Posted by mark in food science on June 19, 2025
Yesterday Andrew MacPherson from our UK affiliate PrismTC presented a great talk on deploying design of experiments (DOE) via Stat-Ease® 360 software for Developing Optimal Espressos. He worked out a clever way to tailor the grinding and brewing conditions to his taste for specific coffee beans based on where they are grown. Brilliant!
Our team at Stat-Ease did something similar, focusing on light, medium and dark roasts with blends of all three bean types; then grinding them to a range particle sizes in varying amounts. Read all about this mixture-process DOE in the September 2016 Stat-Teaser article on Brewing the Perfect Pot of Office Coffee.
Of course, taste is of paramount importance for coffee. However, with the cost of beans skyrocketing over the past 6 months (and likely to increase more as tariffs imposed by the US government on April 5th take effect), it is also good to use less coffee when brewing. First off, going from espresso to a regular coffee machine will be a step forward by allowing a reduction in the ratio of coffee to water. Even better, if you are willing to forego automation, make your coffee via the pour over method—invented in 1908 by Melitta Bentz.
Recently a team of researchers at the University of Pennsylvania created an optimal pour-over process using a goose-neck kettle that achieved an avalanche in the ground coffee, which resulted in the maximum flavor extracted from the minimum amount of beans.* See photos, graphs and figures illustrating their findings at this ResearchGate post. For a translation from physics and fluid dynamics terms, see this April 8th USA Today article by Elizabeth Weise: Scientists release instructions for how to make a perfect cup of coffee.
It would be great to try reproducing these earth shaking (more accurately—coffee shaking) results via a DOE on flow rate, pour height, and amount of coffee. Mainly I would like an excuse to buy a goose-neck kettle like this Coffee Gator.
It hits a lot of hot buttons for feature freaks like me—a surgical-grade stainless steel body, “cool-touch ergonomic handle, brewing ‘golden-zone’ thermometer [I like that a lot!], precision pour spout and triple-layer induction-friendly base” (the hyperbolic bits quoted from their sales site on Amazon).
Hmmm…induction-friendly…so to take advantage of the base I need to upgrade our stove. More gadgetry—hooray! No worries convincing my wife, the expense will be made up by the savings in coffee (ha ha).