William H Calhoun

Introduction

What does a teacher really contribute to learning? ➤

Is it not the student's responsibility to inspire and motivate himself? The teacher leads by example, establishes trust (partly by easing the fear of failure), presents to students interesting or desired topics or skills, and provides instruction and assessment (that hopefully doesn't punish). The rest is up to the student. Or is it? Is successful teaching only measurable by the extent to which a student is somehow induced to learn?

What teachers often share with each other is the craft of teaching; the employment of techniques and the solution to problems. Teachers rarely discuss what teaching itself actually is. It is like asking a fish what swimming is: "I don't know, I just do it."

There is such a thing as teaching. ➤

Teaching is not coaching, though it can include coaching. Teaching is not training, though training can be a part of teaching. Teaching is not just explaining, not just instructing, it is not supervising, it is not facilitating, not babysitting, not managing, not providing services, not delivering curriculum, not simply and somehow the inverse of learning. It is its own activity, its own expertise, an expertise that happens to have student learning as an end goal.

Why define teaching? ➤

If teachers don't define teaching for themselves, others will, and quite likely to the detriment of teachers. The problem is that the "wrong" definition of teaching can harm and interfere with a teacher's ability to really teach. What is a "wrong" description of teaching? Here are just a few examples: babysitting, coaching, facilitating, managing, providing services, delivering curriculum, the inverse of learning. Why are these descriptions wrong? Because the focus is either on behavior control or delivery of instruction, but not at all on what can be described as engagement.

There are two problems. Delivery of instruction includes designing instructional materials and designing tests. Both of these activities can be done on a corporate or academic level by experts, with an eye toward monopolizing, automating, and monetizing such activity. Teachers are just expected to deliver the canned curriculum to students. And much of what could be thought of as engagement is instead thought of as classroom management, often resulting in, at worst, moralistic or belittling approaches to control and discipline. Behavior modification approaches are an improvement, but best would be a sociological approach to adjusting student behavior, directly and indirectly, in the service of engagement.

Teachers need to engage to be effective. The key to this is understanding how a teacher's stagecraft and presence can help students interact with instructional materials. While discipline first, instruction second is a common recipe, it results unfortunately in poor outcomes. Instructional materials cannot teach themselves. Without an engaging teacher, any student is simply self-taught, for better or worse.

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David Labaree - Targeting Teachers

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.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 complete essay on his website: https://davidlabaree.com/2024/07/04/targeting-teachers-3/

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

Posts

The Collision that Formed the Moon

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 video).

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. Here's one version of it on YouTube.

Stacking all the Planets

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.