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October 2019

Reading Astronomy News: Giant Radio Telescope in China Just Detected Repeating Signals from Across Space

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Stocktrek Images, Inc./Alamy Stock Photo

By Stacy Palen

Fast radio bursts have been known since 2007. Recently, China’s FAST telescope has detected a repeat of one first discovered at Areceibo in 2012. This article poses several explanations for fast radio bursts.

Questions:

1) Study the picture of the 500-m telescope at the top of the article. Is this a “steerable telescope?"

Answer: No, this telescope is far too large to be steerable.

 

2) Describe how a telescope that is not steerable “sees” the sky differently than a steerable telescope.

Answer: A telescope like this can see only the portion of the sky that passes through its zenith. Because it is not steerable, it cannot track an object, so the observing time is set by the amount of time it takes for the object to pass through the field of view.

 

3) The signal was emitted from a source 3 billion light-years away. How long has the signal been travelling to reach us?

Answer: The signal has been traveling for three billion years.

 

4) What was happening on Earth when this signal left the source?

Answer: The earliest forms of photosynthesis date from around this time.

 

5) Why is a repeating FRB so interesting to astronomers?

Answer: If the FRB repeats, that rules out a whole class of causes. The object has clearly not blown up, so this is not connected to supernovae or black hole mergers.

 

6) Choose one of the proposed explanations for FRBs and explain in more detail how an FRB could be caused in that way.

Answer: Answers will vary.


Current Events: Supermoons and Other Nonsense

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Credit: NASA/Bill Ingalls

By Stacy Palen

In July 2019, I received a few queries about a “black supermoon.” Since I had no idea what that was, I decided to track it down. It comes from a group of click-bait articles like this one, which are apparently taking off from a random article in Travel And Leisure magazine.

In brief, there is a new moon. It’s the second one in a month. Apparently, the Farmer’s Almanac calls this a “black moon.” This new moon occurs at perigee, when the moon is closest and has a (technically) larger angular size.

This has lately become known as a “supermoon.” The astute reader will note that you can’t even see this supermoon because it's a new moon. (Cue GIF of Kermit the Frog flailing his hands wildly in despair.)

In the last few years, “supermoons” of various kinds have suddenly become news.

A quick query of Google’s Ngram Viewer reveals that the word isn’t even in their database up through 2008, which is somewhat reassuring; it certainly feels like the term suddenly started popping up just a couple of years ago! But this was the first I had heard of a “black moon.”

Why does this matter? More astronomy in the news is better, right? Well, sort of.

Suppose everyone gets all excited about going out to observe the “black supermoon” and it’s nowhere near as interesting as they expect. Thereafter, they are less likely to follow up when something truly exciting happens, like the total solar eclipse that is coming to the US in 2024. (Have you made your plans yet? I have.)

Competing for the attention of the public, at this point, is a remarkably difficult prospect. I see why some outlets would seize on the popularity of astronomy to try to get a few seconds of that all-important attention. But in the long run, this is a failing strategy if the “news” fails to deliver what it has promised.

This particular article provides a good opportunity to help students see when they are being “click-baited” since there is literally nothing unusual happening.

A student who really understands the lunar orbit and phases of the moon will react to this article much like Ralphie in A Christmas Story, when he receives his Little Orphan Annie decoder ring and realizes the whole thing is a marketing ploy.

“A crummy commercial?” he exclaims as he throws away his long-awaited prize.

Given the last few years, I expect to see two or three articles like this over the course of the next academic year. Each time a student (current or former) asks about it, I will use it as a “teachable moment” and recommend that they fully engage their baloney detection kit when reading their news feeds!


Classroom Stories: Psychology and Underrepresented Groups

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B.O'Kane / Alamy Stock Photo

By Stacy Palen

This week in Physics Seminar, we had a psychologist come and talk to us about a number of studies that indicate how stereotypes impact the performance of underrepresented groups. Generally, this refers to women and minorities (although other categories also intersect). The take-home message is that when underrepresented groups enter an environment in which they are the minority, they show a physical autonomic nervous system response. Really—heart rates and sweaty palms and all!

Dealing with this “fight or flight” response taxes their working memory, and they do not perform as well. Several other cleverly designed studies have investigated “stereotype threat” and have shown that when the stereotyped group is engaged in a task in which they are stereotypically bad, they are extremely sensitive to signals that confirm the stereotype.

For example, these groups will have a stronger negative reaction to a poor score on a first exam, and they are more likely to see that score as a signal that people like them are not “meant” to study science.

This is all very fascinating, but the speaker went further and gave us some concrete examples of specific interventions that help level the playing field. Interventions such as in-class discussions about the contributions of women in science may be obvious, but others were less obvious.

For example, one study had women engineering students wait briefly in an office full of items that evoke the male stereotype of an engineer (Star Trek posters dominated by male faces, gaming consoles, piles of soda cans, etc.). A second group waited in a very similar office which had slightly different posters (still science fiction, but less firmly associated with the male stereotype). This room also lacked the pile of soda cans and had an abstract picture of a flower on the wall.

Shockingly, the difference in performance on a subsequent math test was statistically significant, with the women who waited in the stereotype-evoking office performing more poorly. (Men’s performance was not affected.)

Astronomers are lucky. We have lots of examples of a diverse population contributing to our understanding of the universe. Highlighting those examples has been shown to improve performance by those who identify with the specific groups mentioned.

Conversely, highlighting the accomplishments of the majority group negatively impacts performance for the underrepresented group.

Interestingly, the majority group is not impacted in either case because they are not carrying the distracting mental burden of stereotype threat into the classroom!

The take-home message of these kinds of studies is that no matter how well the test instrument is designed, and no matter how much or how well the student knows the material, there are external factors affecting performance. These factors can be lessened by specific (small) interventions, like hanging up a different poster, highlighting diverse scientists, or intervening after an exam to point out that “this material is hard because it’s hard, not because you aren’t good at it.”


Kids in the Classroom

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By Stacy Palen

I teach at an open-enrollment university with a very large number of non-traditional students: nearly all of my students have jobs with large time commitments. Many of them are parents of young children. More than half of them are married.

This semester, something interesting has been happening that has not happened before and it started with just one student. I suspect that the time of the class has something to do with this as it’s at 2:30 in the afternoon, rather than in the morning or evening when I typically teach.

A young mother, in the first week of class, emailed me to let me know that she was having trouble with her child-care arrangements for her 9-year-old daughter, and she wouldn’t make it to class. And also to ask if we were we doing anything “important” that she would miss. LOL. Fortunately, I received this email in advance, and was able to suggest that she just bring her daughter with her. So she did. And her daughter was quiet, but attentive, and even “took notes” on a sheet of paper. She even asked a good question!

So then another young mother, in week four, asked if she could bring her daughters to class, for a similar reason. These two are 8 and 6. Both sat and listened quietly. The 8-year-old raised her hand to contribute to the conversation. Her comment was not entirely on point, but she was brave to do it, and I didn’t mind.

This past week, in week five, I’ve had another bring her daughter to class. I don’t know her age, but she looks to be about 12. This young girl also sat quietly, was not disruptive, and then came to ask me a few questions after class.

This week, the first mother came to see me, and now the 9-year-old who started it all, will be coming to class every other week on Wednesday, which solves a complicated co-parenting problem for her mother, and enables the mother to come to class on those days.

Other students in the class have reacted really well to this, and I think it puts them on their best behavior a little bit, when the little kids pay attention, focus and ask questions. I suppose it’s possible that I may wind up with a class half full of little kids, but actually think that’s unlikely. The mothers have always asked permission, and are very much aware that their kids could be disruptive. It’s probably a little distracting for them, but better than not being in class at all.

This week in Physics Seminar, we had a psychologist talk to us about ways to make STEM fields less intimidating for women. I suspect this is one of them; being a little bit flexible about accommodating the complicated lives of students with multiple obligations.

I’m interested to see how this develops as the semester continues…