Pater Familias » Science

ONE DROP EVERY EIGHT OR NINE YEARS.

Philip — Sat, 04 Feb 2012 02:19:31 +0000

ONE DROP EVERY EIGHT OR NINE YEARS. There are some kinds of crude oil in California that are extremely viscous. So viscous that at room temperature you can turn a glass container of the crude upside down and no drop will flow out. But perhaps you just have to wait a longer time. Instapundit linked to this description of a science experiment (or, as the Popsci article by Amber Williams notes, a demonstration) that has been running since 1927. The physicist who set it up wanted to demonstrate that “tar pitch, a derivative of coal so brittle that it can be smashed to pieces with a hammer, is in fact a highly viscous fluid.” The tar pitch is kept at room temperature. Every eight or nine years a drop (or “dollop” falls and is collected. No one has ever been there when a drop has fallen., but there is now a webcam focused on the tar pitch. This article has the webcam and a picture of tar pitch which has been shattered by a hammer.

DECISION TREES FOR PATIENTS.

Philip — Sun, 22 Jan 2012 03:08:06 +0000

DECISION TREES FOR PATIENTS. Laura Landro’s review describes how Doctors Groopman and Hartzband “examine a formula for rational decision-making often used in economics: Measure the probability of an outcome and place a numerical value on the outcome itself.” The probable value of each medical result can then be compared. The tool described is known as a “decision tree.” It is called a decision tree because there may be a series of outcomes to be evaluated with each choice, and a graph of the analysis looks like the branches of a tree. Here is an example of the use of a decision tree with a drawing of a decision tree. Yoram Bauman, the Standup Economist I posted about here, begins his exposition of microeconomics in THE CARTOON INTRODUCTION TO ECONOMICS with decision trees.

DECIDING WHAT KIND OF PATIENT YOU ARE.

Philip — Sat, 21 Jan 2012 03:18:38 +0000

DECIDING WHAT KIND OF PATIENT YOU ARE. Jerome Groopman (an oncologist) and Pamela Hartzband (an endocrinologist) have written YOUR MEDICAL MIND, which analyzes the role of patient choices in medical decisions. (I have relied on this review by Daniel J. Levitin and this review by Laura Landro.) The premise of the book is that for many medical decisions, there is no black and white answer so that often patients will have to make decisions based on probabilities. The doctor and the patient should work together in doing this. The authors (husband and wife) propose two useful dichotomies: first, patients tend to be maximalists or minimalists. Dr. Groopman was a maximalist until a bad experience with back surgery made him more risk averse. Dr. Hartzband identifies herself as a minimalist, using medicines only when absolutely necessary. Second, a patient can be biased either for or against new technology. Is a patient willing to try a new medical treatment before it has been “proved”? Is a patient willing to let nature take its course perhaps with the aid of “alternative medicine”. The two dichotomies result in four classifications. Mary Jane and I tend to be maximalists who are open to new technology.

VICTORIAN HARPOONS IN TWENTY-FIRST CENTURY WHALES.

Philip — Sat, 14 Jan 2012 22:14:29 +0000

VICTORIAN HARPOONS IN TWENTY-FIRST CENTURY WHALES. Nick and his friend Jane went to the whaling museum in New Bedford recently and were struck by the fact that whales are being found today that are carrying harpoons that were fired in the 1800′s. These articles (here and here) point out that the harpoons provide a new way to estimate the age of the whales. Indeed, they support the conclusion that bowhead whales are the longest living mammals. The bowhead that is the subject of the articles is estimated to have lived 130 years, based on the date of manufacture of the harpoon. Previously, scientist used levels of an amino acid in a whale’s eyes to estimate its age. Presumably, the harpoon information would be helpful in confirming the amino acid method.

The real interest for me is the romance of the find—the reminder that we are not so far in time from the world of Moby-Dick.

A PHYSICIST HAS EXPLAINED AN OBSERVATION BY LEONARDO.

Philip — Tue, 10 Jan 2012 21:08:24 +0000

A PHYSICIST HAS EXPLAINED AN OBSERVATION BY LEONARDO. Instapundit called attention to a recent paper by a physicist, Christophe Eloy, which provides a mathematical explanation for an observation made by Leonardo da Vinci which has never been satisfactorily explained. This article in Wired by Kim Krieger of ScienceNOW describes what Eloy has done. Graphic artists routinely use Leonardo’s rule to create realistic computer-generated trees. “The rule says that when a tree’s trunk splits into two branches, the total cross section of those secondary branches will equal the cross section of the trunk.” If the two branches split into four, the total cross section of those will equal the cross section of the trunk. The article has a mathematical formula to express the rule and some helpful illustrations. The rule actually gives an approximation; the most accurate approximation varies with the species of the tree.

The explanation for why the tree growth fits the formula is that the trees are optimizing resistance to wind forces. This means that research relating to the Eiffel Tower and skyscrapers is now relevant to tree growth.

KLUDGES.

Philip — Wed, 04 Jan 2012 18:20:44 +0000

KLUDGES. The title of the sunk cost article refers to sunk costs as a “memory kludge”. This wikipedia article defines a kludge as: “A kludge (or kluge) is a workaround, a quick-and-dirty solution, a clumsy or inelegant, yet effective, solution to a problem, typically using parts that are cobbled together.” It’s a new word. The OED traces its first usage to a 1962 article in a computer magazine. It seems to be a fairly common term in economics now, and wikipedia says that it is used in computer science, aerospace engineering, and evolutionary neuroscience. The usage in the title of the sunk cost article means that sunk costs sometimes can be used as a proxy or substitute for memory—roughly that “we can’t remember all the analysis that went into this decision, but the amount we spent is a reminder that at one time, we placed a value on the decision of the magnitude of the sunk costs.”

LEAPING INTO SOMEBODY ELSE’S MIND.

Philip — Sat, 24 Dec 2011 21:25:52 +0000

LEAPING INTO SOMEBODY ELSE’S MIND. Ariely provides support for my favorite kind of gift giving—taking on “the great challenge… in making the leap into someone else’s mind.” He says that psychological research “affirms that we…have a hard time seeing the world from a different perspective” and adds: “…whether or not your sister likes the book [you choose], it may give her joy to think about you thinking of her.”

So Christmas gift giving, in the spirit of good will, encourages us to look at the points of view of our nearest and dearest.

DOES COOKED FOOD PROVIDE MORE ENERGY?

Philip — Mon, 12 Dec 2011 03:02:39 +0000

DOES COOKED FOOD PROVIDE MORE ENERGY? Wrangham in the interview says that he was surprised that his paper in 1999 that argued that cooked food provides more energy than raw met with a lot of criticism that dismissed the claim. Wrangham had originally gotten the idea from research in the 70′s that included Wrangham’s eating a wild chimpanzee’s daily diet. When he did, he found himself hungry. He also had some evidence that half of women who ate a 100% raw diet stopped having periods, a sign of inadequate nutrition. However, for the most part, it had been assumed that there was no difference in caloric value between raw and cooked food. It turns out that there has been a journal for 70 years called Meat Science, and there were lots of books on the subject of meat science, but there had been no research on whether cooking made a difference in calorie value. For example, the USA uses “the Atwater Convention for assessing calories in food, a century-old system that treats food as being composed of a certain number of components, each of which has a fixed calorie value”—without considering whether the food is raw or cooked. Wrangham has now buttressed his claim with experiments with mice and can point to evidence that cooking breaks down collagen in meat which makes meat harder to chew and to studies which show that cooking gelatinizes starch, making it easier to digest. Wrangham thinks that when more research is done, “the increase in net calorie gain from cooking will prove to be in the region of 25–50%.”

UPDATE—WHY IT MATTERS THAT COOKED FOOD HAS MORE CALORIES.

Philip — Sun, 11 Dec 2011 02:23:38 +0000

UPDATE—WHY IT MATTERS THAT COOKED FOOD HAS MORE CALORIES. I posted here three years ago about my memory of an anthropologist’s claim that cooking was the greatest labor saving invention of all time because it reduced chewing time. Since then, I found other research on the importance of cooking for human evolution, including this post about CATCHING FIRE; HOW COOKING MADE US HUMAN by Richard Wrangham. Wrangham cited: smaller teeth and jaws, easier digestion and smaller guts, more energy for walking and running over long distances…. Now Wrangham in this interview reports on recent research by himself and his students that shows another basic advantage of cooking. Cooking increases the available calories in food, which was of enormous advantage when hunger was an important issue. (Of course, if you want to lose weight today, then, other things being equal, you may prefer to cut down on how much cooked food you eat).

THE MCGURK EFFECT.

Philip — Tue, 06 Dec 2011 22:53:40 +0000

THE MCGURK EFFECT. I have been claiming for some time now that I am not good at lip reading; Mary Jane is the one who can tell what the disappointed athletes are saying. Apparently I am better at it than I think. I have been introduced to the McGurk Effect. This YouTube from the BBC demonstrates it. When I looked at lips making an “f” sound (“fa—fa—fa—fa”) while listening to an audio of a “d” sound (“da—da—da—da”), I heard the “f” sound. I was instinctively lip reading. Here is a wikipedia article on the McGurk Effect. It was discovered in 1976. It shows that: “The visual information a person gets from seeing a person speak changes the way they hear the sound.” The McGurk Effect results from the brain’s effort “to provide your consciousness with its best guess about what the incoming information is trying to tell it.” Sometimes when confronted with conflicting information from the eye and the ear, the brain processes the information into a third sound (“‘ga’ auditory and ‘ba’ visual produce ‘bga’”). When somebody is watching a dubbed movie, the brain is trying to ignore the visual information.

WERE LEATHER HELMETS BETTER?

Philip — Fri, 25 Nov 2011 22:53:24 +0000

WERE LEATHER HELMETS BETTER? I have posted a number of times on the use of head by football players in making tackles. I began with this post which said that: “With better football helmets, the use of the head to make a hit, a kind of spearing with the helmet, has increased.” Although I was repeating a common assertion, it may be that the belief that modern helmets are better may be mistaken. Christopher Shea in the Wall Street Journal (November 19-20) called attention to a study (which is reported on here in Science Daily) comparing leather football helmets from 100 years ago and modern helmets. The study “compared head injury risks of two early 20th Century leatherhead helmets with 11 top-of-the-line 21st Century polycarbonate helmets.” The helmets were crashed together at various angles to simulate hits that are common in games and practices. The conclusion: “For many of the impacts and angles studied in the lab, the researchers found that leather helmets offered similar, or even better, protection than modern helmets.” Although modern helmets may be better at preventing skull fractures and severe brain injuries, they are apparently no better than the leather helmets at preventing concussion.

PAINTING AN AVERAGE UNIVERSE.

Philip — Mon, 21 Nov 2011 23:34:46 +0000

PAINTING AN AVERAGE UNIVERSE. I encountered the study of the average color of the universe from this article by Edward Tenner in the Atlantic about Jonathon Keats, a conceptual artist who has taken to heart the findings of the study. He has done twelve paintings, each in a flat coat of the average color. “As perceived by eyes adjusted to total darkness, the average color of the universe has the CIELab coordinates 97.7, -0.5, 9.” If you are curious about that average color, the article has photographs of some of the paintings. Keats calls for a Copernican Revolution, which would recognize that “the world is an average place, and that our place in the cosmos is nothing special.” Tenner says that: “The aim of Copernican art is to be the most average artwork in the universe.”

I agree with the character Tommy in my two minute play “Samuel Beckett Looks at the Stars” that most of us know that the universe is very big and we are very small. As I’ve expressed on several occasions in the last five years, my preference is for art that helps me experience my human world.