The SAIL Teaching Framework

This is a condensed version of the complete chart, but it's a good place to start. Click for a larger view (and to download).

July 24, 2023

David Labaree - Targeting Teachers

Cross-posted from William H Calhoun

David Labaree is a historian and retired Professor of Education at the Stanford Graduate School of Education. This essay is taken from his website (https://davidlabaree.wordpress.com/). He introduces the essay thus:

In this piece, I explore a major problem I have with recent educational policy discourse — the way we have turned teachers from the heroes of the public school story to its villains. If students are failing, we now hear, it is the fault of teachers. This targeting of teachers employs a new form of educational firepower, value-added measures. I show how this measure misses the mark by profoundly misunderstanding the nature of teaching as a professional practice, which has the following core characteristics:

  • Teaching is hard
    • Teachers depend on their students for their professional success
    • Students are conscripts in the classroom
    • Teachers need to develop a complex teacher persona in order to manage their relationship with students
    • Teachers need to carry out their practice under conditions of high uncertainty
  • Teaching looks easy
    • It looks like an extension of child raising
    • It is widely familiar to anyone who has been a student
    • The knowledge and skills that teachers teach are ones that most competent adults have
    • Unlike any other professionals, teachers give away their expertise instead of renting it to the client, so success means your students no longer need you
  • Teachers are an easy target
    • Teachers are too visible to be inscrutable and too numerous to be elite
    • They don’t have the distance, obscurity, and selectivity of the high professions — so no one is willing to bow to their authority or yield to their expertise
Here's the link to the essay on his website: https://davidlabaree.wordpress.com/2023/07/20/targeting-teachers-3/

Here's the link to the original publication in Dissent, 2011: https://drive.google.com/open?id=1RvOPUrxd9UKMJGDPLB7UY5ZFlzrUmsHf

December 1, 2019

The Collision that Formed the Moon

Cross-posted from William H Calhoun

I was poking around YouTube looking at videos about where the Earth's Moon came from. The currently accepted theory is called the Giant Impact Hypothesis. Though details differ, the main idea is that a smaller planet collided with the early Earth, and the Moon arose from the resulting debris. This hypothesis continues to be tweaked to this day, and other hypotheses continue to be proposed, all because details remain in the existing evidence that are unaccounted for. It's both delightful and a little surprising that the research is still quite active.

I was looking for an up-to-date simulation of the Giant Impact as opposed to an artist's interpretation. I was hoping that, given the current state of computer simulations, there might be something amazing available. There are older videos on YouTube about the Giant Impact which use pretty impressive artist's interpretations. But artists will sometimes take liberties with the physics if it makes the animation more engaging. What I wanted my students to see was a computer simulation that is based on a mathematical model that is allowed to run unedited and unimpeded. Like this:



This is clearly a simulation, probably run on a supercomputer. There is no question that the imagery is based on a model. You can even see the individual elements, almost like little blobs, for which calculations are being run to determine the next state of each blob.

Eventually I came across this video:



I loved this simulation. You can see the resemblance to the one above. The video is obviously a clip from a longer video, but no credit was given. So I hunted and hunted until I found the source:



This is a longer video featuring the work of Dr Robin M Canup, who is also narrating. Dr Canup is associated with the Southwest Research Institute in Boulder CO, where she has used supercomputer simulations to create and build her Moon-formation models. She has also participated in the production of "data-driven cinematic animations," like the one in the video above.

This video is a preview of a portion of a Fulldome Planetarium show called "The Birth of Planet Earth," produced by Spitz Creative Media, the Advanced Visualization Lab of the National Center for Supercomputing Applications, and Thomas Lucas Productions, Inc., set for release in 2019. (More details in this report and in this website).

As nice as this 2018 mini-documentary is, I still wanted just the simulation, so I edited it out of the video as its own clip and stripped the audio. I thought about adding some kind of background music, or using music from the original video. Dr Canup's narration was pretty good, but just not lined up with the simulation clip. I really liked the idea of the female narrator also being the physicist whose work this was - something I'd be proud to point out to my students. So I copied the audio of her narration (with the music), added it to my clip, tweaked the timing a bit, faded the ends, and then had to stall the beginning of the clip to fit the whole audio. I built an elaborate fade-in with the visuals so the stall would feel more natural. It also allows the viewer a chance to focus on Dr Canup before the visual effects of the collision take over. Here is the final result:



A final note: Dr Canup appears in an earlier, similar production created for the History channel in 2007. There's a low resolution version of it on YouTube.

New Demonstrations

Cross-posted from William H Calhoun

A couple of new quick labs for my students this fall. Thanks physics Twitter!



November 29, 2019

Stacking all the Planets

Cross-posted to William H Calhoun

You've probably come across this idea that all the planets could fit between Earth and the Moon. The usual representation looks like this image I found on Google:


It turns out, it's not entirely true. Here's a good article about this, published in Slate a few years ago. The planets can fit, but you have to make a lot of adjustments.

What got me thinking about this recently was an amazing video I found on YouTube by yeti dynamics (here's YD's channel). He has made a number of what-if? astronomy videos. The video that astonished me was a simulation of the Earth-Moon system with all the planets fitted inside the Moon's orbit. The view is from the Earth's surface, and the speed is greatly increased. It makes your head swim. But there's something spell-binding about these gigantic orbs circling so close to the Earth (that is, if it doesn't give you motion sickness, like it does for my wife).



What really astonished me is how much work it must have taken YD to construct this. He created his assets (images of planets, background landscape, 3-D modeling), programmed the animation, and created the video using Blender, 3dsMax, and Natron.

I was contemplating this Herculean task when I realized that I already had an application designed for astronomical simulation. It's called Celestia, and I've worked with it for years. It comes pre-loaded with visual assets (and you can simply add more), and the animation programming is done with script files, also included, which are easily modified. Celestia's basic job is to model the known universe, but you can also create alternative worlds, alien star systems, and break the laws of physics.

So I made a copy of Celestia's basic solar system script, and started modifying. I didn't want to disturb our solar system, so I chose a new Sun - 18 Scorpio, a star about the same size and composition as our own Sun. Then I started modifying the planetary data. First, I created a spreadsheet to help me work out the distances and orbital times (also called periods) for the planets. This is where I had to work out the adjustments I mentioned above to fit (or stack) the planets. Here's the list of adjustments:
  • The Moon is permanently at apogee (greatest distance from Earth)
  • All planetary orbits are circular (zero eccentricity)
  • All planets are perfectly spherical (mean radius)
  • Pluto is included even though it's not a planet anymore (it fit!)
  • All bodies are evenly spaced (1666 km gap between bodies)
  • Saturn is tilted 45 degrees so the rings won't slice through other planets
  • Planets are not in their traditional order, but in order by size.

I took that last point from YD's video. I did try putting the planets in their traditional order, but the visual result was not impressive. This was an inspired move by YD.

Data was obtained from NASA's Planetary Fact Sheets.

Here's a screenshot of my spreadsheet:


This is a 7½-minute video of the final simulation recorded from Celestia. I've positioned the viewpoint in geosynchronous orbit about 8 miles above the Earth's surface, facing northeast, a 50-degree field of view, with the rate of time speeded up a thousandfold.



In case you download and install Celestia, here is a link for downloading a version of the script file I created. You can put it in Celestia's Extras folder, and modify as you wish.

I have shown this simulation to several people. It's quite mesmerizing. As another physics teacher told me, if this is what the sky looked like, we'd never get anything done. My students like it when I project it onto the big whiteboard in my classroom. I'm not sure there is much educational value to it, though. Students seem to recognize that it's "not real," but do understand that the planets would look like that up close. They don't get right away that it's speeded up, and the idea that the planets have been fitted into the Moon's orbit is pretty abstract. Not many people even spot the Moon. Hardly anyone realizes that there's no gravity in the simulation. With gravity, the whole system would collapse pretty quickly. There's no way this could have formed naturally.

But interesting questions do come up, and students like to guess which planet is which, and they sometimes just watch, like you would watch fish in a fish tank. Lankshear & Knobel, in their book New Literacies, describe the role of the teacher as elicitive. In this case, I suggest that, as a teacher, I am being evocative. And maybe that's OK.

New Physics Curriculum

Cross-posted from William H Calhoun

I was tasked this year with redesigning the physics curriculum at my school. Our state (MA) just upgraded their framework, so we needed to re-align. For the last decade, the state's framework was nothing more than a shopping cart of physics topics. There wasn't even an attempt to distinguish topics from concepts. The state assessment required students to have key vocabulary memorized, and to know how to pick out the right equation and apply it correctly to word problems. And that was about it.

My physics team has only three members. For good or for ill, we are all well-versed in the old state framework and assessment. The new framework is mostly based on the Next Generation Science Standards, so it’s quite different. I was excited about the change, because I think the NGSS is a worthy approach. But it’s very different from the old approach, and I wanted the team to have the time and opportunity to adapt. The new curriculum I wrote is organized in a way that looks similar to the old curriculum, but introduces and adapts the new framework language. The team already has a strong bias toward hands-on, project-based, team-oriented classwork. I wanted the physics team to continue moving in that direction, but to shift their conception of this project-based classwork from demonstration-of-topic to phenomenon-model-interaction.

To help our team, perhaps other science teams, and even our supervisors, to better understand the NGSS framework, I created a concept diagram. The diagram is not based directly on the NGSS framework, but is instead a representation of the new curriculum I wrote. I think of the new curriculum as a particular instance of the NGSS framework.


The old curriculum thinking was topic first, application second. The new curriculum flips that around to phenomenon first, model second. The basic interaction is that the phenomenon informs the model, and the model makes predictions about the phenomenon. We choose an anchor phenomenon that is sufficiently complex, has relevance to the lives of the students, and is interesting or engaging. As an aid in exploring this phenomenon, simpler and perhaps more accessible related phenomena are introduced.

The model is related to other models, largely through shared concepts such as force and energy. Through these core concepts, students can develop a picture of physics as a consistent viewpoint and approach to understanding the world, rather than merely a collection of topics. The model is represented and expressed in many ways. These multiple representations give students multiple pathways for exploring the relationship between model and phenomenon.

Finally, in keeping with the idea that learning comes from doing, I include a summary of what students could do as they explore the phenomenon-model relationship. This list is broadly in line with the goals stated in the standards of the new state framework.

August 14, 2018

Space Junk Joyride

Cross-posted from William H Calhoun

I don't get nearly enough chances to use Celestia in my classroom. I've loved messing around with Celestia for years, but it's the rare student who shares my enthusiasm for astronomy. In class I will use Celestia to demonstrate gravitational orbits - moons around planets, planets and comets around suns, stars orbiting stars orbiting more stars.

During one such class this past year, one of my brightest students asked me if I had heard about the time an asteroid had circled Earth three or four times and then disappeared. I encouraged her to explain further, though I was skeptical. So she whipped out her smartphone, found an animation of the event, and showed it to me. Sure enough, there it was.


The animation had specific dates, and the asteroid had a designation that I recognized as legit; J002E3. I promised the class that I would gather more information for the next class.

Wikipedia has an entry about J002E3, and in that page I found the NASA/JPL animation my student had shown me. I also found an amazing story. J002E3 was indeed first thought to be an asteroid, but later determined to be space junk, namely the third stage of the Apollo 12 Saturn V rocket launched in 1969. The rocket stage was intended to wind up in orbit around the Sun, but it didn't quite make it, and is now technically still in orbit around Earth. It's in a semi-stable orbit, though - J002E3 spends decades circling the Sun before it re-enters the Earth-Moon system, circles the Earth a half-dozen times, and gets shot back out around the Sun. Eventually it will crash into either the Earth or the Moon.

J002E3 orbited the Earth six times from the spring of 2002 until late spring of 2003, and this is what the animation shows. I presented the animation to my students on the SmartBoard, and I knew right away that I would have to change it. The file is an animated GIF, which cannot be paused, have its speed changed, or be run in reverse. The deep blue orbital path, which shows up nicely on a computer screen, did not project brightly enough on the SmartBoard to be seen easily. The GIF's dimensions were too small. I would have to do a little editing and then turn it into a video.

Photoshop is the perfect tool for this. It will read all the frames of an animated GIF and turn them into individual layers. You can edit the layers, and then turn them back into a GIF or a video. I first changed the dimensions, doubling both the width and height. Then I changed the color of the orbit in each of the frames. This took some painstaking effort - about 80% of the work could be done very quickly, but each of the 516 frames had to be carefully checked. I exported it as an MP4 video which I posted on YouTube.



NASA link: https://cneos.jpl.nasa.gov/news/news134.html
Animation versions & credit: https://cneos.jpl.nasa.gov/doc/j002e3/

July 13, 2018

High (Voltage) Wire Act

Cross-posted from William H Calhoun



My brother-in-law Peter visited last year and showed me and my wife some of his favorite short videos on YouTube. When I saw this one featuring a man inspecting high voltage lines, I knew that I would show it to my students. It's a lovely little video narrated by the electrical inspector who talks about his work, and his life, and even tells a story about how his suit is a special kind of Faraday cage.

I knew my students would find this video interesting. There are a lot of intriguing electrical details and small events that could almost go unnoticed, and which could form the basis of some interesting physics questions and demonstrations. Our technical school has an Electrical Technology shop, and students in the shop would already know about this kind of work, and would be excited to watch this and share their knowledge. This video is a perfect example of what I like to add to my instruction toolkit.

The version I first watched on YouTube was of poor quality, and there was no indication of who actually made the video. It was obviously clipped from a longer video about dangerous or exciting work. There are many copies scattered throughout YouTube, and I spent a lot of time hunting for the best and most complete version. I finally found a high-definition version of the clip. I used Filmora to clean up the beginning and the end of the audio track. I did watch other videos about high-voltage line inspectors, but this one best suited my purposes. It's calming, actually, rather than all hyped up, and you get a sense of the man rather than just a focus on the details of the job. The music sets the mood perfectly. There's a joke at the end that mostly goes over my students' heads.

I eventually discovered that the the clip is from an IMAX movie called "Straight Up: Helicopters In Action." It was produced in 2002 by SK Films for the Smithsonian National Air and Space Museum, and apparently aired as a cable TV broadcast by INHD, which later came to be called MOJO HD. I also came across a comment that it had appeared on Discovery HD.