Germans are the Fattest Europeans

Unless its citizens are fooling the Body Mass Index (BMI) with a lot of muscle tone (BMI is useless at measuring whether those of an athletic persuasion are carrying extra poundage outside the gym),  Germany weighs in as Europe’s fattest nation, and is on a par with the United States.

In 2007, the International Association for the Study of Obesity found that that 75.4 percent of  German men and 58.9 percent of  women were overweight. According to a new study by Germany’s Federal Research Institute for Food and Nutrition, the situation is a result of being clueless about food and calories, increasing laziness and, as Reuters notes,  drinking too much beer after eating sausages.

How to Tell a Good Scientist from a Bad Scientist

In a series of interviews with New York Times science writer Gary Taubes on scientificblogging, psychology professor Seth Roberts turns to the question of how do you go about making the judgment as to whether a scientist is trustworthy, especially when the topic is controversial. Taubes responds:

I’m a stickler about the use of words like “evidence” and “proof”. So if someone tells you there’s no evidence for some controversial belief, you can be fairly confident that they’re a bad scientist. There’s always evidence, or there wouldn’t be a controversy. If somebody says that “we proved that this was true” or “we set out to prove that this was true” that’s another bad sign. The point here, as [Karl] Popper noted, among others, is that you can never prove anything is true; you can only refute it. So researchers who talk about proving a hypothesis is true rather than testing it make me worried.

SETH: Yeah, I see what you’re saying. They overstate; they twist things around to make it come out the way they want. They are way too sure of what they…

TAUBES: Yes, and the really good scientists are the ones, almost by definition, who are most skeptical of evidence that seems to support their beliefs. They’re most aware of how they could have been fooled, how they could have screwed up, or how they might have missed artifacts in their experiment that could have explained what they observed. They’re very careful about what they say. If you ask them to do play devil’s advocate, and tell you how they could have screwed up, then at the very least, they’ll say “Well, if I knew how I could have done it, I would have checked it before I made the claim”. So when I’m talking about discerning the difference between a good scientist and a bad scientist, I’m talking about how they speak about their research, the evidence itself, it’s presence or absence.

Worth bearing in mind when you hear something which appears to overturn consensus expressed in strident terms: Where all the other possible explanations for the phenomenon considered? How did the researchers test their theory and data against the best possible countervailing research? Why do their conclusions offer better explanatory power?

Should Fractions Be Scrapped?

Rebecca Goldin Ph.D

According to USA Today, “Fractions should be scrapped” – and the whole world seems to be cheering the potential demise of perhaps the most frustrating and demanding topic in elementary school arithmetic. As the paper reported:

A few years ago, Dennis DeTurck, an award-winning professor of mathematics at the University of Pennsylvania, stood at an outdoor podium on campus and proclaimed, “Down with fractions!”

“Fractions have had their day, being useful for by-hand calculation,” DeTurck said as part of a 60-second lecture series. “But in this digital age, they’re as obsolete as Roman numerals are.”

But before the shouts of joy rise to the power of deafening, take a closer look: No one is actually proposing that the idea of fractions be scrapped; Dr. DeTurck was expressing the opinion that decimal expressions are more relevant and important in the age of computers than ratios such as 3/4.

The point is that every fraction (a ratio of two integers) can be expressed as a decimal expression (allowing for infinitely repeating sequences), and vice versa. So fractions and decimals are two different ways of talking about the same nubmers: rational numbers. Irrational numbers, such as the square root of two or the infamous pi, cannot be expressed as a ratio nor as a decimal, though they can be approximated by them (e.g. pi is close to 3.14).

While DeTurck engages mathematicians and math educators over whether the techniques involving ratios are more or less important than the techniques using decimals, no one is questioning the importance of generalizing from integers to fractions, a fundamental concept which is typically a major component of fourth grade mathematics.

(Editor’s note, Rebecca Goldin is an award-winning mathematician at George Mason University)