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Comment Carbon dating (Score 2) 155

I feel obliged to point out that isotopic fractionation is not "central" to carbon dating. The key to carbon dating is that radioactive carbon-14 decays to nitrogen-14 with a half life of roughly 5700 years, enabling biological material to be dated by its residual carbon-14 content. That is not isotopic fractionation, it's radioactive decay. Isotopic fractionation would be involved if you observed a difference in the ratio of carbon-12 to carbon-13 in plants versus that same ratio in the air.

Comment Re:Because Mars is the best chance for the price (Score 1) 298

Dead on. It's not like you can just look at a pile of dirt (or ice) and tell whether there's something living in it. And you certainly can't do life detection from orbit unless you have a serious biosphere going, which obviously none of these outer solar system moons have. And the Europa drilling ideas that people like to throw around aren't going to be technically feasible in the time frame of the missions to Mars -- if ever.

Comment Doesn't help grade inflation (Score 2) 323

I'm not arguing that this is a good or bad idea, but it won't do anything to change grade inflation. In my experience (as a TA for a number of different classes), college professors look at the point totals at the end of the semester and determine the letter grade cutoffs by hand so that they have the grade distribution they want. I'm not saying they're going through and making sure specific students get a particular grade, just that they want, say 50% A's 30% B's and 20% C's and they'll put the cutoffs where they need to be for that to happen. Just because the essays are graded tougher doesn't mean they can't still give half the class an A.

Comment Re:Associative memory (Score 1) 60

Exactly! What this study ignores, consciously I'm sure, is the affective domain. They basically ask, "which of these image that you don't care about at all do you remember?" They don't ask, "which picture from you vacation is your favorite?"

I think using the word "memorable" is slightly misleading for this reason, because memorable has a connotation that is much broader than merely "remembered". It implies that there is an emotional connection to something.

Submission + - Problems with Truncation on the Common Application (

jaroslav writes: A combination of rigid caps on space and poor documentation of the space limits is adding stress on students applying for college using the Common Application, the New York Times reports. The story explains that the application lists word limits for questions, but actually enforces space limits. As a result, an answer with wide characters, such as 'w' or 'm', may run over space even without reaching the stated word limit. It is not explained why an electronic submission must have such strictly enforced limits.

Submission + - Writing helps women overcome sexist stereotypes 1

An anonymous reader writes: According to a new study, a brief writing exercise can help women in college physics classes improve their academic performance and reduce some of the well-documented differences between male and female science students. The writing exercise seems particularly beneficial to female students who tend to subscribe to the negative stereotype that males perform better in physics, the researchers say. Apparently, awareness of this so-called gender gap can negatively affect women's performance on their physics exams. But, this rather simple writing exercise—aimed at re-affirming an individual's core values—appears to narrow the gap and level the playing field for women who find themselves in this frequently stereotyped demographic.

Submission + - A Clue to Kryptos (

jaroslav writes: The sculptor of the enigmatic installation, Kryptos, outside CIA headquarters has revealed six of 97 letters of the currently unsolved fourth puzzle. Over the 20 years since the sculpture was first revealed three of four puzzles have been solved. The fourth was always intended to be the most difficult, but even the artist is surprised it has taken this long.

Comment Good luck ... (Score 2, Insightful) 360

I wish the people and governments of these island countries well and I certainly think they should try whatever they can to get attention for their plight, but the lesson learned in COP15 is that the major industrial powers of the world are not willing to make major changes in their greenhouse gas emissions. And basically the rest of the world can't do a damn thing to make them.

"Free markets select for winning solutions." -- Eric S. Raymond