Drinking twice as much reduces heart attack by factor of three?
After suffering a mild heart attack (an oxymoron!) a few years ago, I asked the cardiologist if it’s true that a glass of red wine a day keeps the myocardial infarctions away. He said “yes.” What about white, I wondered. “That works too,” said he. Encouraged by this, I wondered if beer might work too. The answer was affirmative. Next I questioned whether two drinks might be even better. After that got endorsed by the cardiologist, I quit while I was ahead. I’ve enjoyed one glass of beer or wine, and occasionally a second helping, every day since. Life is good!
Today I was heartened to see in the HeartCenterOnline Newsletter that a study by Beth Israel Deaconess Medical Center in Boston indicates that two drinks daily help men avoid heart attack. At first glance at the following detail I thought I ought to have more than two drinks:
“There were 9 heart attacks in a group of 714 men who drank more than two drinks daily, and 34 in a group of 2,252 who drank less than two a day.” Unfortunately, if you do the math and calculate the percents by comparison, this statistic becomes a lot less compelling for those who like their liquor. I am holding the line at one drink every day for sure and two at the most, but only when I want to really live it up.
Sound from Sand: Rock Music?
At a vastly smaller scale than Stonehenge, stones ground by natural forces to a well-rounded and relatively regular shape can make very distinctive sounds, which you can hear at song of the Atacama Desert dunes in Chile. According to physicist Stephane Doudy of the Centre de la recherche scientifique in Paris, the volume of sand slides can reach a nearly unbearable 110 decibels — on par with a jet engine. For the complete story of how “self-synchronized avalanches turn piles of sand into musical instruments,” check out Dulcet Dunes by Fenella Saunders of American Scientist magazine. What I find fascinating is that it evidently takes a veneer of salt to make sand sing, so if you really want to hear a tune from a dune, head for a desert that spills into the sea.
Stonehenge blocks demonstrably moved by man — not magic
My youngest brother, an engineer like me and our father, sent us this link showing how a fellow from Michigan, Wally Wallington, single-handedly lifted a Stonehenge-sized pillar weighing 22,000 lbs. I visited Stonehenge in June and learned that, prior to erecting these really large pillars, earlier builders (2000 BC!) put up 80 bluestones, up to 4 tons apiece, that they mined 240 miles away in Wales. These were thought to have been moved magically by the sorcerer Merlin. More likely these were transported much of the distance by raft and overland on rollers as demonstrated by the Millennium project.
I thought the bluestones were the coolest of all that I saw at Stonehenge, but you must look beyond the larger sandstone pillars to see them and appreciate how much older they are. For more on their history, see the Secrets of the Preseli Bluestones by Dr. Colin R. Shearing.
Any sufficiently advanced technology is indistinguishable from magic. — Arthur C Clarke
Minnesota Twins beat the statistical odds once again
On May 17 I reported that sabermetrician Clay Davenport computed 200 to 1 against the Minnesota Twins making the Major League Baseball playoffs. Guess what? Not only did they achieve a place in post-season, they won their divisional championship. Granted, it was very unlikely the way the Twins turned their season around, and it was downright surrealistic for them to end up in first after their very last game. As I blogged earlier, statistics be damned by what we now know:
Twins win improbable division title.
One might do well by betting on the Twins when they are down again in future. For example,at the beginning of the 1991 baseball season, odds on 1990’s last-place Twins winning this year’s title were 100-1. They ended up as the World Series champs. Similarly, in 1987 the Twins went all the way in Major League Baseball. Prior to that season I went to Las Vegas for a conference and saw a betting board with odds at 100 to 1 against the Twins winning the championship. Ever since I’ve second-guessed myself for not betting anything — even $10 would have netted me $1000! Unfortunately, I am a man of little faith in the face of such overwhelming statistics.
PS. Post season results were not good — three games and out for the Twins in their playoff series with Oakland. 🙁 This is a triumph for sabermetrics because the Athletics are led by its biggest proponent —Billy Beane.
Economists shave hairs on whether basketball games are fixed: Any bets on who wins?
In my March 26 blog I reported that ‘forensic economist’ Justin Wolfers, a professor at the University of Pennsylvania, inferred point-shaving from his statistical analysis of 44,120 NCAA Division I basketball games between 1989 and 2005. This new study by University of Illinois economist Dan Bernhardt disputes Wolfer’s contention that statistics indicate point-shaving on college basketball. Perhaps it’s only natural that superior teams fall short of expectations on their winning margin. According to Professor Bernhardt “the statistical properties that Wolfers identified in his paper seem to be intrinsic to the game of basketball itself, occurring independently of whether there are incentives to point shave, and are not indicative of an epidemic of gambling-related corruption.”
It’s good that this new analysis dissipates the cloud of suspicion about point-shaving raised by the first study.
Longer-term perspective on global warming (and other catastrophes)
On March 16th I blogged about the sharp upturn in global temperatures that some liken to the blade of a hockey stick. The blog provides a link to a graph reproduced by the BBC which goes back 1000 years. Aside from questions about how data are fitted, simple changes to scales and other attributes of the graphs themselves can paint very different perspectives on seemingly straightforward scientific questions such as whether we ought to be worried about global warming. Andy Sleeper shows this in part 7 of his white paper titled HOW TO LIE WITH STATISTICAL GRAPHICS. The color-coded graph generated by the U.S. National Oceanographic and Atmospheric Administration is very alarming. However, it only provides 122 years of history and the y-axis scale is restricted to about 2 degrees C. A few figures later in Sleeper’s paper one sees another graph based on 400,000 years of temperatures estimated from core samples of Antarctic ice. It reveals cyclic temperature swings of 12 degrees C! In this context, should a less than 1 degree increase in global temperature be considered abnormal, that is, due to a special cause such as man-made carbon dioxide?
PS. Here’s something to really worry about. The November issue of Sky and Telescope features a heads-up on “The Most Dangerous Asteroid Ever Found” — a 1000-foot pile of rock called Apophis. It will just miss the Earth on April 13, 2029. If Apophis hits a narrow zone — called the keyhole, it will be dragged enough by our gravity to put it on a course that collides with Earth seven years later. One can only hope that NASA’s proposed gravity tractor will pull the asteroid off target and save the planet.
Experimental proof that microwaved water kills plants?
Posted by mark in Uncategorized on September 22, 2006
A fellow graduate from University of Minnesota’s chemical engineering school told me this week that “I am afraid the average person’s level scientific understanding in this country is in the dark ages.” His skeptical comment, with which I am sorry to say I agree, stemmed from an inflammatory email passed along to both of us by a mutual friend, an attorney who has been deemed a “super-lawyer” by his peers. No offense, but I do not think his expertise extends to the scientific arena. (Similarly, I make no claim to knowledge of law.) The email he circulated from internet comes with this cover comment “An engineer friend of mine sent this and added that it ‘Seems to be legitimate!’ Wow!” Attached are photographs from a simple comparative experiment that apparently supports the commentator’s contention that “microwaved anything…corrupts the DNA in the food so the body can not recognize it.” It concludes by saying: “Proof is in the pictures of living plants dying. Remember You are also Living. Take Care.” See the photos and commentary for yourself at Snopes.com — a site maintained by Barbara and David Mikkelson that follow up on “urban legend.” Their articles seem to be well-researched, intelligent, and full of common sense. Why do average people, or in this case — clearly someone far above the mean for general intelligence, seem to be so gullible about legends like this one about the dangers of microwaves? David Mikkelson provides this explanation: “The power of illustrative anecdotes often lies not in how well they present reality, but in how well they reflect the core beliefs of their audience.”
Surveys produce precisely inaccurate findings
In New Brighton, Minnesota, my old home town, the city council paid $4,600 for a a survey that asked how many residents voted in the last election. It found that 47 percent of the 400 respondents said they “always” vote when, in fact, less that 18 percent showed up for the last election. Professor Sandford Weisberg, director of the University of Minnesota’s Statistical Consulting Service, wasn’t surprised by this. He says that “people always want to say what pleases people.” However, the pollster hired by New Brighton claims that the people he surveyed simply “misremembered” that they hadn’t voted. A recent article in New York Times opinion pages* provides much more alarming evidence of misleading surveys, for example, one by American Medical Association (AMA) that reported an alarming rate of binge drinking and unprotected sex among college women during spring break. The AMA survey, supposedly based on a random sample of 644 women, provided a margin of error of +/– 4 percent. However, according to the Times, the survey included only women who volunteered to answer questions — and only a quarter of them had actually ever taken a spring break trip! The article goes on to cite other cases of surveys that produced very misleading results, including one similar to the one done by New Brighton. Beware of what you read about what other people think, especially if it comes from a scientific survey.
*Precisely False vs. Approximately Right: A Reader’s Guide to Polls, by Jack Rosenthal, August 27, 2006
Stat-Ease credited with reporting the world’s largest flying disk
Posted by mark in Uncategorized on September 12, 2006
Our periodic search of internet netted a Google group exchange on “…the biggest Frisbee made”* in which someone named “Burp” (whose email starts with “Beerme”!) provides the link to this incredible photo. It was sent to me in 2002 by Darrell W. Pepper, Ph.D., Dean, College of Engineering, University of Nevada Las Vegas, who said “I enjoyed your article in the September issue of the Stat-Teaser regarding the flying rings/disks with your daughter (Sixth-Graders Experiment with Flying Disks). I just thought you might like to know that we built the world’s largest flying disk (10 ft in diameter) some years ago – as well as a 10 ft ring (using mylar and PVC pipe). I also had a grad student do his MS thesis on frisbee/disk aerodynamics a few years back. See the attached picture of one of our former engineering students (who also played center for the UNLV football team) actually throwing the disk (Adler design – like Aerobie but solid). The disk was made from composite material and foam – total weight was about 20 lbs. The student tossed the disk about 75 feet. By the way, when we transported it to Reno for the annual AIAA meeting (about 400 mi), a wind came up and blew it off the trailer – the student walked over 1000 feet in the desert to pick it up (an unofficial distance record?) The following year I had some students work on a giant machine to toss the disk. It never materialized, but the idea seemed good. We then went on to build solar airplanes, etc. One more thing – there was a report of a UFO disk-shaped object flying over the highway.”
PS. Other readers of my original article on the experiment by my daughter weighed in on the effect of color on the plastic disks’ physical properties, the impact of a learning curve for throwing them, and the throwers’ level of expertise — see item #2 at my October 2002 DOE FAQ Alert. (Feel free to subscribe at DOE FAQ Alert signup.)
*If you are a fan of flying disks and do not mind some playground language, take a look at the topic in rec.sport.disc.