Reading Astronomy News: The Mystery of Titan’s Expanding Orbit

By Stacy Palen

Titan’s orbit is growing, which is unexpected! This article might be appropriate when discussing orbits, outer planet moons, or resonances.

Below are some questions to ask your students based on this article.

1) What did astronomers EXPECT to find out about Titan’s orbit, before undertaking this study?

Answer: They expected to see that Titan’s orbit was unchanging.

2) How much does Titan’s orbit grow each year? Give an example of a common, everyday object that is about that size.

Answer: 11 centimeters (cm). This is a little bit shorter than a pen or pencil, so each year, Titan’s orbit grows by less than a pencil length.

3) Compare this rate to the rate at which the orbit of Earth’s Moon grows. Is Titan moving away from Saturn faster or slower than the Moon moves away from Earth?

Answer: The Moon moves away at 4 cm per year. Titan moves away from Saturn almost three times faster.

4) For how many years did the Cassini spacecraft orbit Saturn?

Answer: Cassini orbited from 2004 to 2017, so approximately 13 years.

5) During that time, how much did Titan’s orbit expand in total?

Answer: 11 cm times 13 years is 143 cm, just shy of 1.5 meters.

6) The semi-major axis of Titan’s orbit is 1,221,870,000 meters. By about what fraction did this value grow during Cassini’s visit to Saturn?

Answer: 1.43 m / 1.22187 X 109 m is about 1 in a billion. Dang.

7) What is “resonance-locking tidal theory?” How does this account for the loss of energy from Titan’s orbit, due to the orbit growing larger?

Answer: This is the idea that if the moon tidally flexes Saturn, in resonance with Saturn’s internal ringing, energy can be transferred from the moon’s orbit to Saturn’s internal motion.

What other questions would you ask your students based on this article? Feel free to leave suggestions in the comments!


Classroom Resources: Using the Workbook in the Online Class: A Plan

By Stacy Palen

Typically, in a F2F class, I use the workbook one day per week. In general, I do this on Friday. For each workbook activity, I’ll usually spend about five to ten minutes introducing the topic and pointing out places where students might get stuck or need a reminder. My astronomy course for fall is not synchronous, so I don’t expect that students will be logged in and working together, or that they will all be working on the activity at the same time.

I truly believe that these learning-by-doing experiences are critical to student learning. We’ve all had the experience of thinking we understood the material until we tried to actually apply it! The workbook exercises are designed with typical student difficulties in mind…so how do I do activities online, when students will likely be working alone, and I won’t be there to help them?

The first thing I need for each activity is a video mini-lecture that students can watch before they begin. I can address the same issues here that I would ordinarily address in the first few minutes of class. If I manage to keep it extra-short, like two minutes, they might even watch it more than once as they work their way through the activity and answer their own questions! I’ve begun creating these videos for the activities I’ll be using this fall, and I’ve shared the first one with you here so that you can take a look and see if it is useful to you.

I plan to set up weekly student hours in Canvas. These are times when students can arrange an “appointlet” with me. (That’s a new word, apparently, for the quick, five-minute interventions on Zoom or similar.) I am using the same time blocks for all of my classes. Still on my To-Do list is learning to use the scheduler in Canvas to see if that has all the functions I need.

Finally, each week, I will open a Discussion thread about the workbook activity due that Friday. This is a place where I can make note of things students found confusing and where students can ask questions.

Students will take pictures of their lab and submit it as a PDF in Canvas. There are a number of free apps that students can use to do this. I’ll grade the submissions in Canvas on my iPad. (Not to sell you on this particular set of products; others probably work similarly!) I’ve been doing this with upper-division assignments for a while now, so I don’t think that it will take me more time than usual to grade their work. In the first week, I expect to do a LOT of tech support.

At least I have a plan now. I don’t expect it to entirely survive the first few weeks of class. As Dwight Eisenhower famously said, “Plans are nothing, but planning is everything.” I’m trying to keep that in mind as we approach the fall semester. I’m sure you are, too!


Classroom Resources: Teaching with Videos: Textbook Chapter Introductions

By Stacy Palen

As I think about what I usually do in lecture, in order to try to capture some of it for the online experience, a few book-related things come to mind. There are a few things I do for each chapter, as general practice:

  • I provide students with an overview of each chapter.
  • I guide students to focus on what I think are the most important points.
  • I spend time orienting them to complicated figures.

All three of these things can be done in a video mini-lecture that students can watch before they read the text. To be clear, watching the video is not a replacement for reading the text. It’s just a way to lead them into the material.

I’ve started preparing five-minute video introductions to each of the chapters in Understanding Our Universe, Third Edition. These introductions page through the chapter, highlighting the text and figures that students should pay special attention to, because I know they will come up again. For example, I know that the cosmological principle will be referenced multiple times throughout the book. So, in the Chapter 1 video, I make students aware that they should pay special attention to that concept.

The first two videos, for Chapter 1 and Chapter 2, are linked.

Let me know what you think, and if you find these resources useful! Like all of you, I’m working away in my office here, trying to anticipate the coming semester as much as possible. I suspect that “Future Stacy” will be very grateful to “Past Stacy” if I can get some things prepared now and free up some time during the semester itself.


Classroom Resources: Teaching with Videos: How to Read a Textbook

By Stacy Palen

As I adapt to teaching online this fall, I find that the one thing I really need students to know how to do on their own is read the textbook. I’ve always assumed they knew this skill because I remember being in high school, checking out the textbook at the beginning of the year and taking it back and forth to school with me. Maybe you remember making covers out of brown paper bags to protect the books… and I remember teachers explaining some kind of note-taking method in great detail that I used for a while and then adapted to my own purposes.

But this falls in the realm of “things aren’t what they used to be.” Some schools now have classroom sets of texts that students do not take home. Some don’t use books at all but use free online materials. Some have ebooks but not hard copies. And even for students who do have traditional hard-copy texts that they can take back and forth, some of them never received instruction on how to read them.

This is interesting, because I have never taken ten minutes of class time to explain to students that reading a textbook is not like reading Harry Potter. Nor have I taken ten minutes to give them a strategy for approaching this kind of reading. It just never occurred to me. (I have given entire assignments to my upper-division classes about how to read a journal article, but that’s pretty specialized.) As I think about what I really need students to do while learning in an online environment, the textbook looms larger, rather than smaller, in my mind. Well, then. If that’s true, I guess I’d better tell them how to do it.

To this end, I made a video, about 10 minutes long, in which I explain my textbook-reading process. This is not a perfect process; it’s not the best process; and it might not be the process you use. But it’s a process that gets students thinking about textbook reading as a skill that they can learn and then adapt to their own needs.

I’m pretty pleased with how the video turned out. I made it on my iPad; I used the “Screen Recording” feature in the “Settings” to capture what I was doing in Notability. Then I edited it in iMovie and uploaded it to Kaltura. There is a little 8-second, University-specific boilerplate introduction that I asked our Marketing/Communications team to make for me so I can drop it into all of the videos I make in the future. This 10-minute video took me about 3 hours to make, but I didn’t know what I was doing. Going forward, I think I can cut that time roughly in half; I need to plan for about 10 minutes of work for each minute of finished video.

I’ll be making more of these, so let me know in the “Comments” section below if there’s a particular video topic that you need. If you need it, other people probably do, too! I’ll see what I can get done.


Classroom Resources: Coming in Fall of 2020: Deep Uncertainties

By Stacy Palen

No one knows what this fall semester is going to look like, and it stresses me out!

We might be back in normal face-to-face classes, but we might be back at half-capacity. Or we might be all online. Or we might start face-to-face, and then the second wave will hit, and we’ll have to go online for the rest of the semester. Or maybe we’ll just have to go online for two weeks, when there is a local outbreak. Or we might need to have replacement materials available for students so they don’t feel compelled to come to class when they are sick. Or maybe none of the above, because of the Yellowstone supervolcano, which I hear is currently scheduled for August…just kidding…I think.

In an effort to get control over the things I can control, I’ve started planning my fall courses as both face-to-face and online, in parallel. This means double the work, but given the magnitude of the uncertainties, it feels prudent.

As I have been thinking about this, and starting to organize resources and activities for students, I’ve also started to make a list of the things that are missing, and I’m figuring out how to pull them together.

Over the next few months, I’ll share what I’m doing to get prepared here on the blog. I’ll be making short videos for students about study skills, such as a “How to Read a Textbook” one, as well as other videos introducing and summarizing each chapter of the textbook. There will also be open-ended questions for LMS discussions that I can factor into students’ grades, and there will be web resources, such as “Using the Web” problems, which can also be found at the end of the textbook. And lots of other things that I haven’t thought out fully yet.

Many of us have taught online for a long time, and many of us have an online section; others, however, do not. I know that, for myself, moving four different courses (not just Introductory Astronomy) into the online environment before the end of August is…overwhelming.

I’m sure we are all feeling frazzled and overwhelmed, so let’s be frazzled and overwhelmed together! I hope you’ll share your clever ideas, resources, online or at-home activities, methods for interacting with students, and so on, in the “Comments” section below. Or drop me a line, and you can even guest-write a post about your idea!

 


Classroom Resources: Using Animations and Simulations in an Online Course

By Stacy Palen

Sometimes, “learning by doing” requires the use of a model or a simulation. It’s not possible for students to go into space far above Earth’s North Pole, or to change the mass of a planet and see how it affects the behavior of the central star.

There are loads of simulations and animations available online. So many, in fact, that it can be bewildering to find what you need, and it can be even more complicated to troubleshoot technology to figure out why one of your students can’t access the resources while another can’t see all the buttons.

Gradually, we’ve been working to create a stable set of straightforward simulations and animations that support the Exploration activities at the end of every chapter of Understanding Our Universe and 21st Century Astronomy. Many of these Explorations are guided inquiry experiments that use one of the interactive simulations or animations.

For example, in Chapter 12, students are guided through an investigation of the H-R Diagram using an interactive graph. When students move the cursor along the track of the evolution of a low-mass star, they can predict and then see the changes in the star. This helps them develop an intuition for the properties of stars in different regions of the H-R Diagram, and helps them learn how stars like the Sun evolve after they leave the main sequence.

Explorations using simulations or animations have pre-built assignments in SmartWork that include hints for difficult questions, and prompt students to explore the interactive graphs in more detail. It’s easy to assign these activities as a unit or as individual questions. You could also write your own questions in SmartWork or in your LMS (such as Canvas), which reference the simulations or animations that your students access through SmartWork.

I didn’t have “online teaching in a global pandemic” in mind when I created this feature. It was “just” something that I did with my classes when I had the luxury of teaching in a tech-enabled classroom. But I routinely assign Exploration activities as part of my students’ online homework. And I suspect I’ll be doing even more of this over the next few semesters!


Classroom Resources: Using "Reading Astronomy News" Online

By Stacy Palen

My favorite way to use Reading Astronomy News is to prompt classroom discussion. The articles at the end of the chapters are short enough that students can read them in less than ten minutes—if they forget to read one before class, they can read it at the beginning of class—and the questions are open-ended enough to spark engaging discussions about other topics that students have been reading about.

I find that if I have a classroom discussion once or twice near the beginning of the semester, I can sometimes regret it. Because then the rest of the semester is full of “Dr. Palen, did you read the Internet thing about the space thing that the telescope saw?” Or other similar types of questions that are, more or less, just like the first one. I almost never know what they are talking about.

At this current time, I feel that this Reading Astronomy News feature is especially important. While it may be true that (as Al Bartlett used to say) the greatest problem facing the human species is our inability to understand the exponential function, it is almost certainly true that the second greatest problem facing the human species is our inability to critically evaluate the news.

Unfortunately, classroom discussions are not what they used to be. While it’s possible to have a meeting on Zoom, a “discussion” really does require everyone to be able to see one another so they can be polite and wait for someone else to finish speaking, and so they can also see the body language that means “That was a joke!” or “I’m taking a risk by speaking up.”

In the latter half of our semester, when we were teaching online, I moved my Reading Astronomy News assignments into the online SmartWork homework system. Each article is available in SmartWork and has a pre-built assignment with a handful of questions asking students to evaluate what they’ve read given the context of the chapter material. I assigned some of these pre-built assignments during the last six weeks of class.

I don’t really know how well this worked. Certainly, students did the assignments and answered the questions. And they did a good job, too. However, it was deeply unsatisfying to me because I did not get any insights into how they were thinking about what they read. My goal with this feature and these assignments is to help students learn to read the news critically, and it’s hard for me to know how well they’re doing this without talking to them. It was beyond me, in the chaos of the transition, to craft questions that asked students to connect what they were reading to what was happening in the world.

Over these next few weeks, I’ll be thinking about how to get the same benefits of a face-to-face discussion without having to meet individually with small groups of students over video conference. Certainly, there are technological capabilities (break-out “rooms” in Zoom, for example) that I don’t fully comprehend yet. I’ll need to find some fellow faculty members or former students to be my “guinea pigs” while I figure out how well this works…


Classroom Stories: The Problem of Students at Home

By Stacy Palen

I don’t know about you, but I have learned more about my students’ living situation in the last six weeks than I have any right to know. I learned that one of my students was homeless and living in her car. I learned that one of my students is living in his parents' unfinished basement with his wife and two children. I learned that two of my (senior-level physics majors) didn’t have computers or laptops of their own, and have always done all of their schoolwork on campus. I learned that several of my students have children and live in studio apartments (and I know what those children are studying in THEIR online classrooms). I learned that one of my students has two very young special needs children who refuse to wear anything but “Underoos” when they are at home in the house, even if mommy is meeting with her professor on Zoom.

And I learned that a whole lot of my students do not have reliable internet access. Of course, I suspected that already—because late last summer, a Facebook friend posted an article about students writing essays on their phones because they lack access to the internet in their homes.

A second friend who teaches English composition at a community college commented that she has a unit on “how to write an essay on your phone,” specifically for this reason.

Back in September, that sent me down a little rabbit hole to this blog post from 2018 which summarized a report from the US Department of Energy.

The take-home message is that while nearly all children ages 3-18 have a computer at home (94%), only 61% have access to the internet.

My University made what I consider to be absolutely heroic efforts to loan technology (tablets, laptops, and desktops) to students who did not have it. For weeks, they kept an office open on campus so that students could come and borrow whatever was available.

Many students were able to take advantage of this, but in the end, there was not enough to go around. (There is also a food pantry which has now moved to three locations off-campus.)

I thought a lot about all of this while I was (rapidly and unexpectedly) preparing to move my classes online. I thought about all of these problems for students:

  • Lack of internet access.
  • Having to share bandwidth with their school-aged children and their spouse working from home.
  • Having to share space with children and a spouse who is maybe not working from home.
  • Hunger, and the plain fundamental stress of major life changes brought on by a global pandemic.

And then I tried to think of the best way to ensure that this unprecedented situation “did no harm;” I wanted students to still be able to learn and make progress if they had the mental bandwidth to get it done. These problems were the primary driver behind my decision to make all of my classes asynchronous.

While I feel a deep sense of loss from not interacting with my students in real time, I’m convinced that this was the best decision for the majority of them. Many students “handed in” their homework in the dead hours of the night. Many students sent me emails at those times as well. Many students thanked me for shifting to asynchronous teaching, although some complained that they “were left to learn it all on their own.” It’s a fair criticism, especially since none of these students actually CHOSE an online course!

After I made this decision, I saw a number of articles from more experienced online teachers, who promoted the idea of asynchronous online classes. And several colleagues (here and at other institutions) reported that they tried to have synchronous classes, but attendance dropped precipitously, and they wound up shifting to asynchronous instruction.

As I think ahead to how I might best organize an online class in the next few semesters, I’ll keep these limitations for students very firmly fixed in the front of my mind.


Classroom Resources: Using At-Home Activities in an Online Course

By Stacy Palen

If you are reading this blog, you are probably already a fan of Learning Astronomy by Doing Astronomy. Often, the best way for students to learn is by doing it themselves. At this particular time, when we have all been asked to move our classrooms home, perhaps for more than just the end of the semester, it may be difficult to see how to make Learning Astronomy by Doing Astronomy possible for students.

This is a perfect time to investigate the chapter-opening figures in the third (or fourth) edition of Understanding Our Universe. The first two pages of each chapter feature an activity that students can do at home with items they have around the house. While I did not have a global pandemic in mind when I wrote these activities, I sure am glad to have them now. I wasn’t thinking that students would not be able to acquire additional tools…I just thought that they were more likely to actually do the activities if they didn’t have to go to the store first.

Half of these activities are observing assignments, such as observing the night sky with the aid of a star chart found in the appendices at the back of the book. It occurs to me that students might enjoy being reminded of these star charts as something nice for them to use in the evenings!

The other half of these activities are experiments or models. For example, students can explore the expanding universe using rubber bands and paper clips, and they can learn about thermal equilibrium using a couple of ice cubes and a few glasses.

All of the activities ask students to make a prediction, carry out the activity, and evaluate their results. Many of the activities lend themselves to photograph submissions in an LMS, like Canvas. A question or two in an LMS quiz or SmartWork homework assignment can confirm whether students have done the activity, and whether they can relate these activities to the chapter material.

For example, one of my favorite activities is the melting-ice-cubes activity from Chapter 17. It very clearly demonstrates that it’s easier for spaces in direct contact to come to thermal equilibrium. Connecting this experiment to the horizon problem requires students to think a little bit about what it means for different regions of the universe to be “connected” or “separated.” Asking them to take a picture of the cups and mark the hot and cold areas makes the cosmic microwave background more concrete, and it creates something swiftly grade-able that ensures that students have done the assignment!

As I plan for online teaching through the summer, and possibly into the fall, I’m working these activities into my course plan more formally than I have in the past. I’m also devising new ones to include throughout 21st Century Astronomy. I’ll be test-driving them over the next year or so. Let me know if there’s a particular topic you’d like to see!


Classroom Stories: Cheating and Exams

By Stacy Palen

We are just past finals here at Weber State, and we have been having a lot of discussions about how the transition to online learning went. Among those discussions is a big piece about student cheating. This was prompted by a faculty member who has taught the online astronomy course for a long time (27 times!) and has usually proctored closed-note exams. During the second half of this semester, those exams changed to open-note exams taken at home (presumably!) without a proctor. The average of student course scores rose 8%, and for the first time ever, no one earned a “D” or failed the class.

Clearly, this was not a controlled experiment. There are several possibilities for why student scores rose, which are not mutually exclusive:

  • Students who are uncomfortable with going someplace new to take proctored exams were more comfortable at home.
  • Students who are normally overwhelmed by a closed-book exam did better with an open-book exam.
  • Students cheated with one another by sharing answers.
  • Students cheated by looking things up online.
  • Students used a “service,” such as “Take My Online Exam” or “Online Class Hero,” or something similar.
  • Something else we haven’t thought of yet.

Figuring out what’s going on here, and why, will take more data, and probably some more experiments. We feel compelled to figure it out, because we want to maintain the integrity of the profession, and we want to help guide students to be better people.

Fighting against cheating can be draining. I recall a professor, for whom I was a TA in grad school, who carried out quite sophisticated statistical cross-correlation analyses of the in-class multiple-choice tests in order to catch people cheating on exams. He seemed to enjoy the challenge. I did not, and I found that spending so much mental effort on distrust really damaged my ability to find joy in my job. (Not to make it all about me…but I think students benefit when I’m full of joy, rather than furious.)

I take a different track. Even in my face-to-face classes, I give take-home, open-book, open-note, and written exams that students have several days to work on. I came to this solution by focusing really hard on what I actually want students to know or be able to do.

I don’t actually care if students can recall things; I care if they can figure out things. I also care to give them feedback about their reasoning. Consequently, I don’t give multiple-choice exams. All by itself, that makes cheating a lot harder. (Yes, it’s a gigantic pain to grade 120 final exams by hand. But it’s also a gigantic pain to run sophisticated statistical cross-correlation analyses, and change them every time the testing software changes.)

I don’t think students will ever not have Google (or something similar) at their fingertips, so it’s fine with me if they look things up. I write an exam that presumes that they actually do have Google, or the textbook, at their fingertips to look things up. Making this assumption lets me ask questions that are a lot harder to figure out, and therefore a lot harder to Google directly.

I do care that they “attend” class (for a certain pandemic value of “attend”), so on the exam, I ask several questions that are trivial if they’ve actually been in this class for this semester, but are impossible if they haven’t. (And I vary my lectures and materials accordingly.) This has the added benefit of automatically penalizing students using a test bank or an online service; they can’t get those points, and I don’t have to do anything special about it.

But the most important thing I do is try to make the exams personally compelling. I write a story for them, and then I drop them in it. For several years now, I’ve used a “zombie apocalypse” narrative. (In the post-COVID world, that might not be the best choice!) I used to drop them on a desert island.

In the future, I might try having them imagine they are teaching their kids about the sky, or they’ve been abducted by aliens, or that a time machine has transported them to the deep future. The common feature underlying all these scenarios is that they are on their own. I think the story matters; it makes the material feel relevant (even if they know zombies aren’t real), and it gives them an incentive to try to solve it themselves.

This semester, in the abruptly online experiment that we were all thrown into, I found that I had little to change about this practice. I had to think a little harder about the fraction of “attendance” questions that I wanted to ask, and what made for a fair question of this type. (I specifically referenced Astronomy in Action videos instead of our in-class lecture.) In my class, the average on the pre-COVID midterm was within a few points of the average on the post-COVID final, and the overall course average was just over 75%, which is where it usually is.

There are so many tools now, and so many different ways, to carve up a class into compartments that teach or test each content area, skill, or attitude; take a look at them, and figure out which ones will do the best job for the things you care about. Be sure to start by asking yourself this important question: What is it that you want them to know or be able to do? What are the deeper values you bring with you to the classroom?

Then, figure out how to design your assessments to reach those goals and teach those values. This may be overwhelming this semester, but as you look ahead to future semesters, you may find that you are changing a lot of things anyway. Changing the way you write your exams may save you the time and effort you currently spend on arranging proctors or catching cheaters, which will ultimately make it harder and less rewarding for students to cheat.