Sunday, October 11, 2020

My district bans a Jewish surname...

...from emails sent to district-managed student accounts. Here's the story:

In COVID-era Distance Learning, I have found Socrative to be a useful platform for administering student assessments. Among its useful features is the ability to send students their own individual scored test, showing which questions they answered correctly and which ones they answered incorrectly. The results can be sent to student email accounts with the push of a button. [You are correct to assume the instructor had to enter those email addresses into Socrative. But it's a one-time investment.]

This is a great feature for when we do Test Correction Journals.

But in my very first attempt to leverage this feature, it failed. I had, of course, tested the feature before using it with students. And it worked. But when I sent my students their test results, students insisted they did not receive them. I tried it using Chrome, I tried it using Firefox. Nothing worked. I had to create a privacy-respecting, individualized way to tell students which specific test items they missed. I created one breakout room per student, joined each one—one at a time, and announced which items they missed. While class time was burning.

I quickly came up with a functional workaround for the next period, but it fell short of what I needed it to do. And why didn't the student email solution work? 

Students suggested that the district blocks third party emails from student accounts. The vendor, Socrative, meets all legal privacy standards. District tech services said they do not block third parties. Further investigation indicated the emails were blocked because they contained objectionable content. That offensive content appeared in the following question. TW: "Objectionable Content."

[Secrets of the Psychics] Psychologist and former palm-reader Ray Hyman found that he had the greatest success with clients when he  

A. gave a straight-up reading in accordance with palm-reading guidelines 

B. told clients the opposite of what he saw in their palms 

C. imagined that he lived in an earlier era 

D. assumed his clients were skeptical of palm-reading and his abilities

There it is: the objectionable content, clear as day. What's that? You didn't see it? Look again. "hymen" is right in there. Prurient anatomical terminology titillation that would offend any community's standards of propriety. High school students must be protected from such filth.

Okay, not "hymen" exactly, but "hyman," a simple misspelling of a highly salacious, practically pornographic word. Okay, not "hymen" or "hyman" exactly, but "Hyman," a not uncommon Jewish surname. I presume my college hall mate's name, Steve Hayman would trigger that comprehensive filter, too, lest bad actors use simple misspellings to skirt content filters. 

Some might judge the content filtering of Jewish surnames (that are not anatomical terms) as anti-semitic. I'm confident the San Juan Unified School District doesn't intend it that way, but here we are. "Ray Hyman" triggered a full and immediate IP ban due to the district's sweeping content blocking protocols. 

I was given no reason to hope that this filter would be removed by my district's tech services, now that they are aware of the embarrassing error. It seemed as if the onus was on me not to include terms that would trigger bans, and I should just know what all those terms are.

The filtering is clearly far too aggressive and highly impractical. Blocking my instructional program (without notification) for the "crime" of including a Jewish scholar's name? That's beyond a bad look.

It's indefensibly paranoid and ignorant, in my assessment.

UPDATE: This is apparently just another instance of The Scunthorpe Problem, or as Tom Scott calls it, The Peniston Problem. 

Saturday, October 10, 2020

RT;DL The Tower of Bottle

In the pre-blog, pre-social media days of the mid-1990s, when the World Wide Web was Alien-birthing from nothing (1994) to everything (1995), I was involved with the Southern California Alliance of Mentors for Physics Instruction and its Southern California Area Modern Physics Institute. Yes, two SCAMPIs in one. John Jewett (Cal Poly Pomona) and Roger Nanes (CSU Fullerton) outdid themselves on the acronyms!

Somebody at the California Department of Education liked what SCAMPI was doing, and wanted to get four Northern California teachers involved. I was chosen/selected to be one of them. Jessica Downing, then the Science Department at Esparto High School (now IB coordinator at Inderkum/Natomas) was selected as well. She and I conducted SCAMPI workshops throughout Northern California during those years.

I got this demo idea from her.

The gist is to show that the molecules in a jar of hot water are moving faster than the molecules in a jar of cold water. Just add food color and wait a minute. 

But while we're here, let's add some value. Lay a playing card on top of the hot water and flip the bottle over. The card stays in place and the water doesn't spill. 

Set the bottle mouth down on the cold bottle and remove the card. The result is surprising.

Then re-insert the (a) card and flip the configuration over so that the cold water's on the top. Remove the card. And it's a different outcome.

Last, a few questions of balance or imbalance. If you were nervous that I wouldn't shoehorn a Zoom participant reaction poll in, ease your worried mind.

Google Doc: Demo - The Tower of Bottle 

HTML Preso: Demo - The Tower of Bottle

Single-shot video of the complete demo


Thursday, October 08, 2020

RT;DL Blowout—Newton's Laws Edition

My use of Pasco's Lenz's Law demonstrator as a blowgun to explore the equations of motion is discussed in a previous post. That's an activity I don't do in my regular Physics class, because number puzzles aren't a priority there.

In this activity, I introduce the blowgun to Physics, do a quick speed determination, and then detail how Newton's laws of motion apply to the various portions of the Hero's Marker's Journey.

How are Newton's third, first, and second laws relevant to when the marker (bullet) was in the tube (barrel)? Between the barrel and the box? When caught by the catch box?

I do this after all three laws have been taught in class. It's a nice review.

For example, when the marker is in the tube, Newton's third law is relevant in that the air pushes the marker forward while the marker pushes the air backward. 

Newton's first law is relevant in that the marker at rest would have remained at rest, but was acted on by an unbalanced, external force applied by the air. 

And Newton's second law tells us the acceleration of the marker will be proportional to the force that the air applies and inversely proportional to the mass of the marker. 

In the end, we ponder how to make a faster-moving bullet based on Newton's laws. I can't blow any harder. So we modify the bullet. 

Is this demonstration activity really just an excuse to do another blowgun activity in class? I mean... what are you even talking about right now? That's ridiculous! Why would you even suggest such a thing?

It really is a nice review of Newton's laws. 

Google Doc: Demo - Blowout (Newton)

HTML Preso: Demo - Blowout (Newton)


Monday, October 05, 2020

RT;DL The Newtonian Shot

I'm embarrassed to confess that I don't remember the name of the physics teacher who shared this demo at the January 1986 MSTA Meeting in Lansing. I do recall driving past many cars that had slid into the ditch on the road from Ann Arbor that morning. It was windy and icy. And cold.

But the demo stayed with me, and I worked it into my curriculum early on. It was my first Show & Tell at an NCNAAPT Meeting (Spring 1992, American River College, IIRC). 

I think it's a great demo for the Newton's Law unit. There have been times when securing toy dart guns was a challenge. They can last for many cycles, but they were built as inexpensive toys, not precision science apparatus. Fortunately, Arbor Scientific has become a reliable source

I wrote a post about this demo previously, when I recorded some nice high-speed video of it. It includes a few more specifics.

Here's the RT;DL stuff:

Google Doc: Demo - The Newtonian Shot

HTML Preso: Demo - The Newtonian Shot (including convenient Zoom participant reaction instant poll)

As ever, my presos are designed to support my storytelling and do not stand on their own terribly well. (Like a backup band with no lead singer.) And you can see I use aluminum support rods to help with the simultaneous launch. I launch the darts from ceiling-level down to my countertop so students can see the landing point. I protect my concrete countertop with a wood plank.

Monday, September 28, 2020

RT;DL Cannonball - Ball dropped from moving ship

Another classic demo that can elicit excellent classroom discussion. A cannonball is dropped from the mast of a moving boat. Where will the ball land? This nicely confronts our inner Aristotle.

In my version, the premise is laid out, the landing point options are described, and students are asked to produce arguments supporting three of the five possible landing sites: one that they believe, and two they could convince others of (as good attorneys).

A straw poll is conducted (now with Zoom participant reactions), then students are asked to defend their various positions. After the classroom discussion/debate, a final vote is taken. 

I warn them to vote carefully. "Physics is a democracy, and whichever outcome gets the most votes will  be correct. The universe will accede to our wishes. Please vote responsibly!"

Then we see the actual outcome. First in my animation; eventually in the classic Project Physics footage from 1968. In face-to-face instruction, I also carry it out using a discontinued Pasco product (Ballistic Cart Accessory with Ball Drop Attachment). So sad to see that combo go.

Lastly, I ask students how the demo could be altered so that the ball would land at the other locations that were offered in the premise. The 1968 footage shows one such modification. I leave it to students to think of the others.

Student sheet: Demo - Cannonball

HTML Preso: Demo - Cannonball

The HTML export from Apple Keynote had a few wee quirks this time. Mostly in that while most of the splash sounds are muted, the audio from the 1968 video (muted in my preso) comes through loud and clear in the export.

Further discussion in the comments.

Sunday, September 27, 2020

RT;DL The Clever Dumbbell - Tension & Inertia Demo

A classic and popular demo. I do it in Conceptual Physics, Physics, and AP Physics 1. And I use a 5-lb dumbbell and kite/packaging cotton string. For years, I used a cast-iron dumbbell. But I broke floor tiles on occasion, and there was that one time the wheel-like nature of the dumbbell ends allowed it to roll onto a student's open ... toes. So I found rubberized hexagonal-end dumbbells. And I use a cardboard catch-box with scrap paper to protect the tiles.

After posing the initial question: Which string will break when the bottom string is pulled, I have them work through some leading questions.

Instead of having students predict which string will break, I have them request a string for me to break. Once they understand this paradigm shift, they request the bottom string. And I oblige. Eventually I break the top string, too. This can be navigated in the preso, alone. But I prefer to do the demo in my empty classroom because I can.

The efficacy of this demo lies in the dependence of the outcome on the presenter's technique. If it were a 50-50 coin flip each time, the demo would not have any pedagogical value. Some ponderables are offered post-demo, too.

As is a continuing theme in my RT;DLs, the student sheet is a Google Doc and the preso is an Apple Keynote preso, exported to HTML. These exports work delightfully on computers. Not so well on tablets or phones. 

This one takes a bit of practice to navigate. 

Things shown in images but not in words: strings break when they are stretched beyond their limit by tension greater than the sting can withstand. A rapid pull stretches the bottom string through its limit before the dumbbell moves very much, thus keeping the top string from being stretched. A slow pull allows the top string to be at greater tension than the bottom string, allowing it to reach its limit before the bottom string does.

Student sheet: Demo - The Clever Dumbbell

HTML Preso: Demo - The Clever Dumbbell

Saturday, September 26, 2020

RT;DL Blowout: A tour through the equations of motion

Near the close of the last century, I wrote an article for The Physics Teacher extolling the unadvertised virtues of Pasco's Lenz's Law Demonstration tube. 

Sure, you could use it to demonstrate Lenz's law, but that fine aluminum tube seemed pricey, so I was keen to justify the expense. You can tap it with a mallet (or on the ground) while holding it at various places to produce different notes. The Q of aluminum is great for this. You can stand it up on its end in your classroom to demonstrate unstable equilibrium. 

But for my notion of classroom theatrics, the best unintended use for the tube was as a blowgun. 

For this RT;DL I prepared a tour through the equations of motion with the blowgun acting as my vehicle. it is very much up to the task. I do this in my AP Physics 1 course only. Regular Physics students don't really need the exercise in number puzzles that the equations of motion afford. The year's too short.

In any case, I blow a marker pen through the tube and arrange two photogates near the muzzle to help determine the exit speed. It's over 60 mph!

Once the exit speed is determined, we figure out the acceleration of the marker while it was in the tube. Over 20 g's.

We also figure out how long it took the marker to exit the tube once its motion began. Then we investigate where the marker was when it was at the half way point (in time) along its journey through the tube.

The preso is enhanced with photos and high-speed videos. And an instructive(?) blooper at the end.

Google Doc: Demo - Blowout

HTML Instructor Preso: Demo - Blowout

HTML Student Lesson Companion: Demo - Blowout [Instead of worked out solutions, "Show that..." prompts are provided.]

Exploratorium friends, Don Rathjen and the late Paul Doherty, turned the blowgun idea into a nice Snack: Marshmallow Puff Tube.

Wednesday, September 23, 2020

RT;DL The Great Bullet Race

I run this demo in AP Physics 1. I don't run it in Physics. Why? Projectiles is not a topic I teach in Physics. We tend to spend more time in kinematics than kinematics is due. It wasn't a big topic in California Science Standards Physics (RIP). It's not that big a deal in AP Physics 1. It's virtually non-existent in NGSS Physics. If you are among the few, the happy few—the band of brothers and sisters—who teach a year-long AP Physics C-Mechanics, have at it!

But physics teachers of all stripes love, embrace, and perhaps cling to our kinematics. Maybe after a decade of NGSS Physics and a generation of retirements, kinematics' star will begin to fade. I have my doubts. Kinematophilia seems to have inordinate inertia. </soapbox>

In any case, we still regard this demo as a classic. [We don't seem to have a universally agreed-upon name for it. Or if we do, I don't know what it is.] So when it came up this year, I spent some time in my empty classroom trying to get some useable high-speed footage. 

Here's the student sheet and preso I cobbled together. (The Mythbusters segment is included.) Oh, and where a prediction is called for, Zoom participant reactions are solicited (yes, no, go slower, etc.).

Google Doc: Demo - The Great Bullet Race

HTML Presentation: Demo - The Great Bullet Race

I found the embedded videos in this HTML export to be a bit cantankerous—practice before using in class. Arrow keys to advance. Clicking in a video activates a scrub bar at the bottom and allows you to scrub forward/backward in that video.

Maybe you can get some use out of these; maybe your district won't let you use it. Guns and bullets are discussed, modeled, and used.

[RT;DL is remote teaching; distance learning]

Tuesday, September 22, 2020

RT;DL Inertia in Action

[RT;DL is remote teaching; distance learning. Where we show our attempts to bring extant lessons into the COVID-19 era.]

In the old days of face-to-face, in-class teaching, we did a station lab activity involving inertia experiences. It was called "Inertia in Action."

I retooled it into a video-based demo in which small groups could view segments, discuss prompts, and record their ideas on a Google Doc. It may not be your cuppa. But it works for me, given the circumstances. 

The Google Doc is here: Demo - Inertia in Action.

The HTML export of my Keynote press is here: Demo - Inertia in Action. This is nice because to can advance it at your own pace. But it has trouble on phones and tables, so...

A video of the presentation is posted to YouTube: Demo - Inertia in Action. More compatible, but viewers must stop and start the video on their own.

Here's the video. It doesn't make much sense without the prompts.

Saturday, September 19, 2020

Physics with Dianna

Learn physics from Physics Girl, Dianna Cowern. 

If you really want to lecture over Zoom this year, godspeed. If you'd rather do ... anything else with your synchronous time, let Dianna nail down the basics for you. Feel free to supplement to your heart's content. But I'm confident Dianna can handle intro exposition more effectively than I can. This is what she does.

Dianna's Intro Physics Class: Trailer - Physics 101, AP Physics 1 Review with Physics Girl

Never taken physics before? Want to learn the basics of physics? Need an AP Physics 1 review before the exam? This course is for you!
In this class we will cover these topics:
1D Motion
Free Fall
2D Motion
Newton’s Laws
Free Body Diagrams
Circular Motion
Gravity & Orbits
Energy & Work
Energy Conservation
Angular Momentum
Simple Harmonic Oscillations
Electric Charge
DC Circuits