Gifting a telescope December 9, 2020
Posted by aquillam in Astronomy.add a comment
So you think you might want to give someone a telescope for the holidays, and you don’t know where to start. Well, you’ve come to the right place. Of course, my first piece of advice is to consider binoculars instead.
Binoculars are great. They’re easy to use, and don’t require any accessories. They’re also super useful for all sorts of other things, like bird watching, sporting events, or opera (though really, good astronomy binoculars are a bit bigger than opera glasses!) A good pair of 7×35 binoculars can hang on the hook next to the door, so they’re ready for use in 10 seconds. They’re easy to carry on a hike, or stick in the glove box or carry-on for travel. They’ll pull in mountains on the Moon or the moons of Jupiter even in the city, and if you find someplace dark, they’re easy enough to hold to be able to spot the beehive cluster in winter or M13 in the summer. Add in a tripod bracket and lightweight tripod and you’re ready for a tougher challenge, like the rings of Saturn or the ring nebula, still in under 10 minutes.
When looking for binoculars, the first number is magnification, the second is aperture. Magnification makes details easier to see, but without aperture there won’t be any details. Aperture determines how much light the binoculars (or telescope) can collect. The more light, the brighter and more detailed your image. Usually though, he want to be able to hold binoculars. The bigger the aperture, the heavier the binoculars get. I recommend sticking to something 10 x 50 or smaller, unless you use a tripod.
But, if you’re sure you want a telescope, the most important thing is to get something they’ll use. Nothing beats trying out a scope before you buy it. Check with your local library, since many have telescope loaner programs. Or get in touch with your local astronomy club to see if they have a beginners night. If you’re lucky, you might even have a camera or hobby shop that carries good telescopes. Of course, in the time of Covid, anything in-person is hard. Checking places that do reviews, like Sky and Telescope magazine or the https://www.cloudynights.com/ forums is a great place to find out if a ’scope is worthwhile.
For a starter ’scope, you want something lightweight but sturdy, quick to set up, and easy to point. There are few things more frustrating than watching Jupiter zip randomly through the field of view because the telescope won’t stay steady.
I really like tabletop newtonian telescopes as a starter. These telescopes have a mirror in the bottom to collect the light. The mirror is usually 3 or 4 inches in diameter, and that size is what determines the aperture. I’ve used a Celestron FirstScope and found the views were decent, and the ’scope was easy to use and sturdy enough to do some traveling. Orion and Meade make similar telescopes which also get good reviews. I recommend getting a small folding table to go with it. To use these telescopes, you basically set it on the table and push the tube around to point it. There are no frills, no bells and whistles. You’ll need to know you way around the sky to really use it, but you won’t break the bank on it either. I’m still using the 4″ tabletop ’scope I got for Christmas 40 years ago! Expect to spend $50 – $100.
A slightly bigger newtonian style telescope is called a Dobsonian. These are meant to sit on the ground. They’re easy to use and give you a lot of bang for your buck. However, they take up a lot of space and they’re unwieldy to move. They’ll also require some periodic maintenance, called collimation, to keep all the elements aligned and the view looking good. On the other hand, you can often find used ones in the Cloudy Nights classifieds! Orion made these popular, but all three companies make good versions. Several companies also make dollies for these so if you can store it someplace where you don’t need to move it over high door sills or up and down steps you can really get a lot of aperture for the money. I recommend starting with a 6 or 8 inch, with a focuser that accepts 2”wide eyepieces. A used 6” can be found for $200, and there really isn’t an upper limit.
You’ll find Newtonian style telescopes with tripods in the 3 – 6” size too. However, the tripods are often flimsy or hard to use, and I haven’t found one that I could recommend.
I’ve also checked out a few 60 and 70mm refractors, but a 3 – 4 inch mirror is so much better than a 2 -3 inch lens that I can’t recommend a small refractor. The one exception is the Galileoscope, which I love as a teaching tool. It comes completely disassembled, and can be used as an optical bench, if you want to experiment with the lenses. Really, its a nice optics science kit that can be assembled into a mediocre telescope. If you’re willing to spend $200 – $300, Orion and Celestron make nice refractors in the 80 – 90mm aperture size. Meade also makes them, and usually for a little less money, but I’ve found their tripods to be flimsy, with sharp edges. You might be able to find a Meade telescope without a tripod, then find a better mount, but that’s probably more effort than you want to put in. Or look for one that is closer to the $300 mark, and gets good reviews.
Those companies also make some entry-level go-to telescopes. Go-to is the term for a mount that will automatically move the telescope to the target for you. I’d be wary of any of those that cost less than $500, even used. They can be rather tedious to set up and align, and some of the control parts can’t be replaced when they become outdated. There’s also “Push-to”, which is where there is some device that will tell you which way to move the telescope. These are usually add-ons you install yourself. They’re popular with Dobsonian owners, and are an economical way to get a telescope that will tell you where you should point.
There are other companies out there too. You’ll find Tasco and Bausch & Lomb in department stores and even drug stores. They’re usually ’scopes to avoid. There are also several companies that make really fantastic telescopes, but are much more expensive. There’s even a company here in Michigan, Planewave, that makes stunning telescopes on ingenious mounts, but way outside my price point! Orion, Celestron and Meade make high end telescopes as well. Once you’re looking at those, you’re net looking at a starter ’scope anymore, and it’s probably not going to be a good gift unless you have input from the person you’re buying it for.
Creating effective and engaging online discussions June 24, 2020
Posted by aquillam in Science, teaching.Tags: active_learning, community of learning, online instruction, teaching, tools_for_collaboration
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With links for Canvas Discussions and Piazza where appropriate
As we prepare for fall semester, I’ve been creating some documentation for my department. Occasionally, people outside my department find these useful, so I thought I’d blog them too.
It’s been well established that students understand and retain more from classes where they are able to engage with their peers. Additionally, working with large and diverse teams is a necessary life skill (and one employers value), so it’s well worth including as a learning goal for your class. However, building a community of learning poses a special challenge in the online classroom. Many instructors turn to the discussion board as the tool for community building. As with all tools, how you use it matters.
If you want your students to engage with the discussion board, the first thing you need to do is establish its value. The obvious way to do that is by assigning points to it. There is some evidence to suggest that assigning points at the beginning of the class is valuable, especially during the period of group formation. However, if you set a fixed requirement (e.g. five good posts), most students will fulfill that requirement and stop. Also, if the stakes are too high, students become more concerned with matching the rubric than in genuine interactions. An alternative to points might be badges (support for Badgr for Canvas), but so far most students don’t place a high value on digital badges. To build a community, you need to share with students why you’re asking them to engage with each other. Whether you simply tell them what the research says or share the research literature and citations is up to you (see links at the end for a few of these.) Best practice may be to include points for discussion board posts with the first few assignments, but not make the discussion board a distinct element for graded assessment, and remind them of the purpose regularly. This gives them the motivation to get started, but keeps the focus on social learning over assessment.
Once you’ve established why you want them to participate, you need to establish the expectations for how to participate. Providing clear guidelines can help you avoid some of the major pitfalls, and provide guidance for students who may be anxious about group work online. There are three things you really need to do: establish the rules of engagement, be present (but not too present), and make it manageable.
First and foremost, layout the ground rules. For example, tell them they need to write complete sentences, no personal attacks, no taking over the conversation, and no lurking. Give them examples of good posts and bad posts. How often have we seen the interaction that looks like “I totally agree with <student>. I love <fill in the blank>. I really like what they said about liking <fill in the blank>.” That’s a great interaction with copy-paste, and maybe makes <student> feel validated, but it’s not engaging with the material or furthering the conversation. Also, make sure that they know what good behavior looks like. Respondnig to someone with “that argument sounds stupid to me” really isn’t any better than “that’s a stupid idea.” Think about what you would expect of them if they were actually in class. How would you react to any of the above interactions in the classroom? Give them that guidance up front. Also, if you are going to assign points to the discussion, especially if you’ll have them do peer evaluation, provide them with a rubric. In Canvas, you can connect the rubric to a graded discussion. Best practice is to make it fairly generic so you can use the same rubric for every post. You may want to pin the instructions and rubric to the top of the discussion board. Adding a rubric to a graded discussion in Canvas, pinning a post in Canvas, pinning a post in piazza.
You need to be present regularly, and let them see that you are there. Establish times when you’ll be online, and times when you won’t respond. Establish expectations such as when and how often they should post, whether or not they should expect you to respond, and when they should expect to respond to each other. Again, think of what you would do in person. If the students are having a good conversation, keep out of it. If the conversation is faltering, give it a push.
If you have a very large class, you may need to break it into groups to make the conversations manageable – discussion section sized rather than lecture sized. This is especially helpful if GSIs will be grading, or if you want students to always respond to the primary prompt. Creating group discussions in Canvas Creating groups in Piazza. It can also be helpful for you to show them how to adjust their settings. Some discussion boards default to emailing participants every interaction. You want them to be active on the discussion board, not buried under email! how to adjust settings for Canvas discussion boards How to adjust settings in Piazza
Using an icebreaker in a discussion board is valuable. It’s the first post, so it establishes how the board will work. It helps students get to know who else is in the class, and you can use it to help students find peers with similar goals, or to find peers with different skills. Require both a primary post and a couple responses to other students. You should call out particularly good interactions and illustrate why they’re good interactions. Model the behavior yourself. Respond to several students as if you were one of the group, trying to further the conversation. In short, participate in the icebreaker the same way you expect them to participate in the regular class discussion.
Put discussion board participation on the course calendar, and send reminders the same way you would for any other assignment. Treat it like a required part of the course even if you aren’t assigning points to it. For Canvas Discussions, make it graded or check the “Add to Student to-do” box. For Piazza, create a calendar event in Canvas and link to Piazza Check for students who aren’t participating, and follow up with them. If they have some challenge that limits their participation, do what you can to address the issue. Reiterate your reasoning for using a discussion board and its importance to the class.
Keep in mind that plain text is not always the best tool. This is especially true if students need to do math or artwork. Go ahead and type the formula for the volume of a sphere in plaintext, you’ll see what I mean! Many discussion tools allow alternative posting options such as images, video, or files. The more flexible you can be, the more willing some students will be to participate. Make sure to model and respond to these posts yourself.
It’s a lot easier for students to simply respond to your post, rather than interacting with peers. But you’re trying to build a community, not hold 100 personal conversations on the same topic. Force them to interact with each other by having a cut off, like 6 hours, or 5 posts, after which instead of responding to your prompt, they have to respond to their peers’ responses. Provide them with guidance, or you’ll end up with the “I like what you like” non-conversation again. Have them make value judgments, such as which response has the most important issue or hardest problem and why. Or have them look for the response that generates a new question, and respond with that question, or see if you can answer someone’s question. Make it clear that the goal is always to add something new to the conversation. Ask them to assess whether or not their response lends itself to more conversation, or stops it.
Once you’ve established how to use the discussion board, it’s time to start teaching with the discussion board. Consider if you were meeting them in class, what would you want their interactions to look like? How would you guide them toward a genuine discussion in person? If there is a good conversation going, keep out of it. If the conversation stalls, add a new prompt. Don’t be afraid to let the conversation wonder. Remember, this is the space for students to explore with each other. Let them follow their curiosity, at least as long as it doesn’t devolve into a discussion of weekend plans. If it seems appropriate, you can give accolades in the discussion board, but again don’t interrupt the conversation. If you want to acknowledge a student’s work but don’t want to interrupt, you can always send a private message or email them. Similarly, if someone behaves inappropriately, or makes a mistake, you may want to PM/email them, unless a public reprimand really is what’s called for.
Writing a good discussion prompt is a whole other conversation, so I’ll save that for a new post.
Below are some good references and further reading on using discussion boards.
Amanda Page and Miriam Abbott. A Discussion About Online Discussion. https://www.facultyfocus.com/articles/online-education/discussion-about-online-discussion/
Mark Lieberman. Discussion Boards: Valuable? Overused? Discuss. https://www.insidehighered.com/digital-learning/article/2019/03/27/new-approaches-discussion-boards-aim-dynamic-online-learning
The links in the following include the UM library proxy encoding. You may need to be logged in through the library for the links to work.
Delaney D, Kummer T, Singh K. Evaluating the impact of online discussion boards on student engagement with group work. British Journal of Educational Technology. 2019;50(2):902-920. doi:10.1111/bjet.12614.
Kwok-Wing Lai (2015) Knowledge construction in online learning communities: a case study of a doctoral course, Studies in Higher Education, 40:4, 561-579, DOI: 10.1080/03075079.2013.831402
de Castro, V.B., Sridharan, B., Watty, K. and Safari, M. (2020), The impact of learner engagement on performance outcomes: a longitudinal study in accounting education. Account Finance. doi:10.1111/acfi.12640
Please don’t unfriend me April 8, 2020
Posted by aquillam in Astronomy.Tags: NaPoWriMo
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I'm sorry I missed our lunch But I read this article today From Facebook About de stressing By getting rid of all The people who stress You out unnecessarily. You know the ones - They show up in your feed 'Cause once 3 years ago You had a conversation In the comments Of a friend of a friend You used to know But you've kinda Lost touch since They stopped using Facebook. But this friend of a friend of a friend Liked this aggregator 5 years ago So Facebook thought You should check out The latest story it has And I was reading it and I started to wonder Which of my friends Thought it was a good enough Article to share? But I can’t figure that out. So I have missed our lunch And I am starting to wonder If it was shared by a friend Or if it was Facebook... Its A.I. Trying to warn me That I have become That person The one who stresses other people out.
NaPoWriMo 2020 April 1, 2020
Posted by aquillam in Astronomy, poetry.Tags: bad poetry, humor, NaPoWriMo, poetry
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Like many others this year, I am working from home. Maybe I’ll have time for some blog updates, or poetry. I won’t promise to write one every day, but we’ll see how many I do get out.
You may regret following me.
Here’s a limerick to kick things off. Limericks are always an excellent choice.
This verse is neither, I fear Particularly clever or clear But as poetry goes It certainly shows You couldn’t do worse than start here.
Sideways Orion 