GRE issues; binary star anomalies

Keivan Stassun (Vanderbilt) was at NYU all day, giving a morning talk about his very successful STEM PhD bridge program and an afternoon talk about stars (as they relate to exoplanets and other multiple systems). There was also a great discussion in-between, with academics from around the University in attendance. During lunch, Stassun emphasized that if there is one, single take-home thing we can do to improve the way we run our PhD programs, it is to stop using the GRE as an indicator of merit. He said that there is now abundant, redundant information and studies that show that GRE performance is a very strong function of sex and race, even controlling for scholastic aptitude. The adoption of the GRE was, of course, a very progressive thing: Let's judge applicants on objective measures of merit! But it turns out in practice that it does not measure merit. Most of us (myself included) think about the GRE anecdotally (what was it like for me, or for my students); but if we think about it systematically, I think we will find that we shouldn't be using it if what we want is to admit the best possible students. Stassun: Testify!

In the afternoon talk, Stassun showed some very tantalizing and very perplexing evidence that stars in trinary systems might be physically different from stars in binary systems! He showed that for "hard" eclipsing binaries, the consistency of the stellar radii and luminosities and masses with a deterministic set of relationships appears violated for binaries that have a distant tertiary companion. That is, the distant companion seems to affect the stars in the binary. The data set is still small, and it could be a fluke, but the observation makes clear predictions and presents an awesome physics puzzle. He also talked about the flicker method for determining stellar surface gravities, which I have discussed here previously.

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