Chinese grow cotton on the far side of the moon
Early this year the Chang’e 4 (named for the Chinese Moon goddess) landed on the moon and sent out the Yutu 2 (Chinese for “jade rabbit”) for a short hop on the surface. The mission achieved a first by growing cotton. Never before has mankind grown plants on the surface of another world. Unfortunately, when the sun set (as it does every two weeks) they quickly died from the extreme cold—minus 62 F.
“Huddled together, the seedlings resembled a miniature, deep-green forest.”
– Marina Koren, “How Do Plants Grow in Space?” Jan 30, 2019, The Atlantic
The next step will be to build a sustainable garden on the moon or, better yet, Mars. Along these lines, NASA recently posted the finalists of the “BIG Idea Challenge 2019” to develop planetary greenhouse concepts. If you’d like to experiment on growing plants on the Red Planet, pick up some dirt from the Martian Garden. Students at Villanova who tried this in 2017 found that onions, garlic, kale and hops grew well, which would make an interesting diet for Mars colonists.
Recreational reading off by more than 25%
Posted by mark in pop, Uncategorized on February 24, 2019
I’ve noticed that none of my many offspring or their significant others read newspapers (that I know of), while I and many others of my generation keep up with at least one daily publication. This report by BookRiot bears me out—passing along Bureau of Labor Statistics that Americans 15 years and older spent an average of only 16.8 minutes a day reading non-work (or non-school) materials in 2017—down from 22.8 minutes in 2005. According to BookRiot, we fall far behind India, the world leader, India, who came in at nearly over 90 minutes of reading per day. Given their literacy rate of 60% versus the USA’s 99% level,* that is quite impressive.
The New Yorker points out that the average American reader is reading more. However, this is counteracted by fewer people reading anything at all, falling from 26.3 per cent of the population in 2003 to 19.5 per cent in 2016.** That worries me–over 80% of Americans who, evidently, only watch TV. Read these reports and weep.
“People in the U.S. spend 10 times more time watching TV than reading.”
– Sarah Nicolas, BookRiot
**“Why We Don’t Read, Revisited”, Caleb Crain, June 14, 2018
A blog about blob
“Americans are getting fatter…and shorter” said the headline in the Venice Florida Gondolier Sun last month. The fatter bit was easy to swallow (ha ha), but the second part of this news–the lessening heights–caught me short (yeah, another bad pun).
Here are the average body measures for 2016 gleaned by the Gondolier Sun (Bob Mudge) from this just-released survey by the Department of Health & Human Services (HHS):
- Men 5 feet 9 inches, 197.8 pounds, 40.3 inch waist
- Women 5 feet 3.6 inches, 170.5 pounds, 38.7 inch waist
Mudge reported that the average man is four-tenths of an inch shorter than in 2006. At this rate I figure that men will be reduced to the size of a mouse by the year 3716.
Meanwhile, the New York Times (Nicholas Bakalar) noted that men have gained 8 pounds since 2002. Doing my math on weights projected to 3716 I calculate a massive 1170 pounds for these future mouse-sized men. That is dense (as are my projections)!
My frivolous extrapolations notwithstanding, the realities of actual measurements by HHS are harsh. Is it too late for New Year’s resolutions? If not, I am working on increasing my height in 2019.
“People tend to overreport their height and underreport their weight.”
– Cynthia L Ogden, epidemiologist and senior author of HHS’s National Health and Nutrition Examination Survey
1994 Hot Wheels car wins 2018 Christmas time trials on Corkscrew Crash track
Santa brought my grandson Archer a Mattel Corkscrews Crash track this week. Archer’s been busy ever since running time trials in triplicate on the 48 Hot Wheels cars in his set and computing averages for each group of runs. Considering he’s only in first grade, Archer shows a lot of promise for being an engineer like me, my father and my grandfather (if I do say so myself). However, he needs a bit of work on deciphering how to record times that end in single digits on the hundredths, for example, Archer wrote a time of 1.08 seconds as 1.8—without the zero. I’m working on this. Decimals are tricky for needing to kept in place.
Being overwhelmed with data, I sampled out 12 cars from the dozens that Archer has tested thus far and typed the results into Design-Expert® software’s tools for this one-factor (categorical) comparative experiment. They came out highly significant with very clear divisions between the slowest and fastest cars. (Full disclosure—Archer did not fully randomize the trials, another thing for me to teach as he matures, but I will wait a year or two to try.)
The fastest run—taking less than 1 second to slither through the Corkscrew-was made by a vintage Malaysian entry: the 1994 Mattel Hot Wheels Power Piston Viper Strike. You can see this highlighted in the graph (the bars show least significant differences at 95% confidence).
The trials are continuing at my house now. I am reverting to my ‘Hot Wheels shuffle’ stride when walking about—carefully limiting my step height to avoid stepping on the metal cars. The ones with the pointy fins can be very painful. But it’s all for a great cause. Experimentation!
Dream come true: Homework banned and school days delayed
The Wall Street Journal this week reports that, for the sake of “student wellness”, school districts across the USA are now banning homework [1].
The U.S. Department of Education figures that, on average, high-school students (those without the “get of jail free” card) spend about 8 hours per week on extracurricular assignments. Girls spend an hour more than the norm and boys an hour less, thus there’s a two-hour gender gap on homework. (You be the judge as to what this implies on relative intelligence. I don’t dare!)
Naturally, parents with ambitions for their son or daughter do not favor this trend to relieve academic pressure. Many evidently move their child to private schools that load on several more hours of homework every week. That would be a blow—being yanked away from all your friends at Easy Street High.
It would be worth it if more homework leads to a significantly better education. WSJ suggests that this may not be so for elementary students. That seems sensible. But what about high school? The author of The Battle Over Homework, Duke professor Harris Cooper, says that studies show a positive correlation of homework with achievement [2]. He advises that high-schoolers put in at least 90 minutes a night but beyond 2.5 hours the returns diminish (and any chance of a social life).
Meantime, other school districts, perhaps some that ban homework (that would be double dope!), have moved back their start times to provide more sleep for students. For the heads up, see these Shots from the December 12th NPR Health News on Sleepless No More In Seattle.
I can only say that my quarter of 8 am organic chemistry as a freshman at university did not go well. My notes provided a record of frequent nodding off by my pen trailing off every few lines. That was before I discovered coffee and became addicted to rising early.
Count on placebo effect to counteract colds this coming season
Posted by mark in Consumer behavior on November 23, 2018
In anticipation of seasonal sniffles and hacking coughs I restocked my supply of throat lozenges today. The selection ranged from generics at less than one dollar for a 30-count bag to brands going for several times that price. I see on Amazon a popular choice called “Thieves” that go for $40 for the same quantity that I bought for 97 cents!
Evidently (per National Institute of Health) cough medicines’ effect is mainly placebo. If you do not believe this, go ahead and buy the most expensive lozenges—it will surely make you feel better: Belief enhances the power of a placebo, which means “I shall please” in Latin. You also should consider stocking up in a costly painkiller called Placeberol—laced with Inertaminophen that’s featured in the New York Times Magazine earlier this month* (just kidding).
By the way, the opposite of placebo is the nocebo effect—a belief that an inert ingredient will cause harm to your health. It can be a killer according to this report by the BBC that you can think yourself to death.
My prescription is to maintain a positive attitude to the efficacy of cough drops but pay as little for them as possible. While awaiting the cure for the common cold, I don’t see any alternative.
Talking turkey on extrapolation—do not stick your neck out!
“Extrapolating patterns beyond their natural range can lead to false conclusions” PhD statistician Christine Anderson-Cook in the October issue of Quality Progress. * That should be obvious to everyone. Unfortunately, though, one naturally “eye fits” the final leg of every graph straight out into the beyond of the X axis, thus overlooking the possibility of an imminent bend such as the one shown here by Gapminder. A classic case of this occurred a decade ago when a consensus of forecasters predicted that all of the world economies would experience continued expansion in 2009—none foreseeing the Great Recession. **
“Avoid Linear extrapolation … The turkey’s first 1000 days are a seemingly unending succession of gradually improving circumstances confirmed by daily experience. What happens on Day 1001? Thanksgiving.”
-John E. Sener (Source: Consortium for the Advancement of Undergraduate Statistics Education)
Be careful out there!
* “Straight Line or Not?” p45.
** Financial Times, “An astonishing record – of complete failure”, Tim Harford, May 30, 2014
“Data are profoundly dumb”
Posted by mark in Basic stats & math, Uncategorized on October 22, 2018
This is the controversial view of Judea Pearl and Dana Mackenzie expressed in “Mind over Data”—the lead article in the August issue of Significance. In this excerpt from The Book of Why these co-authors explain “how the founders of modern statistics ‘squandered’ the chance to establish the science of causal inference”. They warn against “falsely believing the answers to all scientific questions reside in the data, to be unveiled through clever data-mining tricks.”
“Lucky is he who has been able to understand the cause of things.”
– Virgil (29 BC)
Pearl and Mackenzie are optimistic that the current “Causal Revolution” will lead to far greater understanding of underlying mechanisms. However, by my reckoning, randomized controlled trials remain the gold standard for establishing cause and effect relationships. Only then can the data speak loud and clear.
Science class a real blast
Making your own erupting volcano is a classic experiment to do at home or in science class. Some, such as the ammonium dichromate one in the video, should not be done without strict supervision and safety precautions.
However, the standard experimental volcano with vinegar and baking soda generally does not cause much harm; that is, until an overzealous mom in India took it to a new level with a blast that injured 59. Fortunately, as reported here, the two students who went to hospital came out intact. Perhaps a non-working volcano might be advised in future.
Hurricane forecasters getting in the zone with their cone
Posted by mark in Nature, Uncategorized on September 13, 2018
Owning a home in Florida, I keep a close eye on the National Hurricane Center (NHC) forecasts throughout the June-through-November season. I see that Florence is now predicted to make landfall around mid-day tomorrow just south of Wilmington, North Carolina—the gateway to the aptly named Cape Fear. Even though that’s less than 24 hours away, it’s still subject to a broad zone of uncertainty–on the order of 100’s of miles. However, it’s very impressive that the NHC forecast made 48 hours ago remains right on. According to a Wall Street Journal report yesterday their 5-day conical projections have improved by more than 100 nautical miles (115 land miles) in radius over the past decade. That’s even more impressive.
However, WSJ advises we’d best remain very leery of the NHC’s spaghetti plots (an alternative to the cone), because they include very simple forecasts along with those that are state-of-the-art. This can be very disconcerting as I discovered when Irma came along a year ago to graze my place along the west coast of Florida. You can see in this Business Insider report on Irma that, only 3 days beforehand, this hurricane’s predicted landfalls ranged from Louisiana to Massachusetts. The article says that NHC suggests that people not focus on the specific tracks. That seems obvious to me based on the ridiculously high variance. I’d like to see these tracks vary by thickness according to the sophistication of the models—the thinner the weaker.
In any case, let’s hope that Florence fizzles out, after all.