The Magic Circle

The Northern California and Nevada Section of the American Association of Physics Teachers held its Spring Conference at Lake Tahoe Community College Saturday, April 21. Beautiful campus; beautiful day.

In the back of the meeting room, officers had prepared a poster of "Mister Equipment" (Mystery Equipment). There were photos of strange-looking apparatus. New teachers often inherit apparatus whose purpose is not intuitively obvious. At meetings, there is a healthy mix of new teachers and veterans. The vets can often identify and describe the mystery apparatus. I hadn't seen the lonely poster until the end of the meeting, when an officer asked if any of the apparatus were—as yet—unclarified.

Even when I made a hasty scan of the assorted oddities, I passed an item at the top of the poster. It was titled "The Magic Circle." It wasn't really a piece of apparatus. It was a simple graphic image.

"That's mine!" I exclaimed. "The Magic Circle is my 'invention.'"

The Magic Circle is a kind of graphic mnemonic I designed in 1988 because Susie Klippi was just not getting graphical kinematics. She wanted to; she was trying. But it wasn't happening, and I wanted to help her. I did the best I could as a still very green one-year "veteran."

The context is the challenge of being able to translate between position and velocity graphs during uniform accelerated motion. The velocity graphs have diagonals, and the position graphs have curves. Physics learners have trouble with these things because it's really calculus that's going on here. The slope of the position graph indicates the value of the velocity graph, and all that jazz.

I spent too much time on kinematics back in those days, and gave it too much weight in the scheme of things. Still, it was my own "No Child Left Behind" that compelled my to design a mnemonic that would help struggling students get past this hurdle.

At the end of graphical kinematics units in subsequent years, I would reveal The Magic Circle. At that point, students had been slogging through the exercises, some with more joy than others. When I show the Magic Circle now, students' minds are ready for it, and a wave of happiness \ briefly sweeps through the classroom. But students soon complain: "Why didn't you show us this 'trick' in the first place?" Rather than engage them in the finer points of pedagogical philosophy, I simply tell them to add this to the growing list of ways I've managed to disappoint them.

I eventually prepared a manuscript for publication in The Physics Teacher, but it was rejected by then-editor, Cliff Schwartz. I still show the trick to my second-year AP students, where graphical kinematics still holds some importance. But they are less in need of the mnemonic. All in all, The Magic Circle © 1988 by Dean Baird has faded in significance for me.

But there it was on Saturday. I gave a quick, impromptu lesson in the oddly-configured meeting room. It was not my best presentation, and I don't think I sold The Magic Circle to any of the conferees still present at the end of the day.

Here's the unpublished manuscript if you're interested.

The Magic Circle: A Training Wheel for Graphical Kinematics

Rio Americano staff flash mob

My friend, Christy Thomas, is Rio's tireless Student Government advisor. Along with a secret cadre of students, she put in the hard labor to organize a staff flash mob for today's rally.

YouTube Link 1. I am mostly obscured by tall Max K in this one. Such good fortune! More videos of this historic event will likely emerge, though. So I'm not out of the woods just yet.



YouTube Link 2. From the Senior Section. Much better sound and I'm nearly invisible. Win win!

ExploratoRio 2012 Time Lapse FINAL

DEVELOPING: ExploratoRio time lapse sequences

ExploratoRio time lapse sequences. My Canon S3-IS has an intervalometer function which will take up to 100 exposires. I set it to take one shot per minute. Here's what I caught.

SETUP


SETUP + DAYTIME OPERATIONS


If I get any more time lapse footage tonight, I'll post appropriate embed links later.

Harmony and dissonance: More on the singing roads

HARMONY
When I developed the "Science is Fun!" activity discussed below, I should have known that Honda's Musical Road in Lancaster was not the only musical road in the world.

It turns out there at least four. And there's a web page devoted to the phenomenon. It's part of the Sound Tourism website. Want to drive them all? Pack your bags! Here's where they are:

1. Lancaster, California, USA, Musical Road - "William Tell Overture"
2. Melody Road, Japan - "Memories of Summer"
3. Anyang, Gyeonggi, South Korea - "Mary Had a Little Lamb"
4. Gylling, Denmark, Asphaltophone

There's a nice "video jukebox" on the page that allows visitors to see news clips relating to each of the roads.

DISSONANCE
If you listen to the Musical Road as depicted on the 2009 Honda Civic Musical Road ad, you hear one version of tarmac William Tell Overture.



If you listen to posted YouTube videos of "regular folk" driving the Musical Road in Lancaster, the tune is significantly different. And not for the better.



Did Honda autotune the road song for their ad?

According to the Musical Road page on Wikipedia, the Lancaster's tuneful tarmac was moved from one location to another due to complaints of local residents about the noise.

The timeline was as follows: in early September of 2008, Honda's Musical Road opened. In late September, it was paved over. In mid-October, the musical road was reconstructed in a location farther from residents. Perhaps the September road was better and the October road was worse.

The location shown in the Honda ad appears remote; the location in the YouTube videos appears remote. But the tune in the everyman videos is quite off.

The Wiki page review is less kind: "The rhythm is recognizable, but the pitches are so far off that the melody bears only a slight resemblance to the William Tell Overture. ... It is likely the designers made a systematic miscalculation which affected all the groove spacings."

And that was the review of the "good" version from the ad. My own take is more forgiving. Remember, it's not that the talking dog speaks well, it's that he speaks at all.

UPDATE: Sound files offered as evidence of Honda's auto-tuning.



User Finale (with a 20% speed increase to match Honda's higher-speed pitch)



UPDATE: This one appears to be in the new location. And the banter between our investigators is too cute not to include. It sounds that same as the "original" road, with the same off-off-notes, so I'm sticking to my theory that Honda auto-tuned certain notes in their TV ad.

A MISTAKE IN THE MECHANICAL UNIVERSE?

I think I just saw a mistake in a video I've been showing since about 1990. If I haven't mentioned it before, I'm sometimes a bit slow on the uptake.

I'm not talking about the errant reference to 1655 as the year Newton worked out Universal Gravitation. Or the estimate of a firefighters weight as "90 kilograms," or the pronunciation of Georg Simon Ohm's first name as "George."

The Mechanical Universe episode to which I refer is "Waves." The error is in the episode's depiction of water waves.

Water waves are "combination waves." That is, they are neither purely longitudinal nor purely transverse. Particles on the surface of water do not move forward and backward, nor side to side relative to the direction of wave propagation.

Instead, these particles travel in ellipses or circles. My student teacher, Marissa Swanson, recently showed me a nice set of animations developed by David Russell at Pennsylvania State University. The page has animations for longitudinal waves, transverse waves, water waves, and Rayleigh waves.

Rayleigh waves (a form of seismic waves) are one result of an earthquake. They are combination waves, too. So a particle on the surface of the Earth travels in an ellipse or circle when a Rayleigh wave passes through it.

But here's the thing: water waves and Rayleigh waves are akin to chiral opposites.

When the crest of a water wave passes through, a particle of water moves forward (in the direction of propagation). When that particle "rides" the trough, it moves backward.

When the crest of a Rayleigh wave passes through, a particle of earth moves backward (opposite the direction of propagation). When that particle "rides" the trough, it moves forward.

1. Check the Penn State animations.

2. Check The Mechanical Universe "Waves" at timecode 19:00 in the discussion and animation of water waves. If my video capturing skills were greater than they are, I would have embedded this as an isolated video clip. Here's a link to a subtitled clip—proceed directly to 4:34.


The water waves are depicted as Rayleigh waves!

The narration announces the overall effect as "giving the familiar undulation of the watery surface." But it doesn't. The surface shows convex crests with pointed troughs. The Penn State animation shows the more correct concave troughs and pointed crests.

Don't get me wrong. I'm obviously a huge fan of The Mechanical Universe. And it wasn't until I had the Penn State animations in my head that I saw the disparity. I'll admit I'm excited to have stumbled across this because I hold The Mechanical Universe in such high regard.

Me? I never make mistakes in anything that I ever due! So if this is old news, don't tell me. I'm giddy with excitement only a true nerd could appreciate.

UPDATE 1: I now Google-own "mechanical universe mistake." Can't wait to tell my mom!

UPDATE 2: My friend, Dan Burns, reminded me that the most egregious error in The Mechanical Universe universe was the narration that accompanies the "Special Relativity" episode. Viewers will recall the sequence involving "Albert" (Einstein) and "Henry" (Poincaré, americanized). In the deepest depths of an animated illustration of the relativity of simultaneity, Henry is referred to as Galileo. Students have been known to jump through a window behind that blooper. That's not the kind of error that slips past anyone for 20+ years.

UPDATE 3: Upon further examination, it appears that the "Henry" of the Mechanical Universe simultaneity animations is actually Hendrik Lorentz.

Science is Fun—a vibration/sound demo suite

Science program funding can be a sad thing. But it can also be a funny thing. This year, I was lucky enough to have a $1000 budget for consumables. I don't always have such a luxury, but it can be something o a challenge to classify what I need and use as "consumable."

In physics, we ten to benefit from large, one-time capital outlays. These investments can endure through thousands of student contacts. But they don't qualify as consumables.

One item I did get with my consumable budget is a class set of Arbor Scientific's Talkie Tapes.

I allowed the potential for classroom use marinate in my mind up until our waves unit. Last Monday, I set about the task of writing a student handout o accompany the Talkie Tapes.

I decided the student activity would qualify as a demo rather than a lab. My initial write-up consisted of Talkie Tape use instructions, alone. The essential point was to connect vibrations to sound.

While doing the activity in class, my serendipitous mind stumbled onto extensions and enhancements.

By Wednesday, the activity also included my skeptical lesson involving "backmasking," And my disembodied musical box mechanism. And Honda's 2009 Musical Road commercial.

All these "tangents" we're items kicking around in my waves unit, but they didn't really have a home. Now they do.

We do the back asking activity first s that students understand audio pareidolia (constructing a pattern where no pattern really exists). So when they try to decipher the "tale of the tape" (audio embedded in the bumps of the Talkie Tape), they understand that it helps to have a hint. The title of the activity provides such a suggestion.

After hearing the Talkie Tape through air and bone conduction, students amplify the sound using Dixie cups. Great time to bring in the disembodied musical box mechanism and talk about the amplification it enjoys when connected to bigger air movers.

Then it's time to enjoy the large-scale version of the Talkie Tape: Honda's 2009 Musical Road project. We close by comparing the road to the tape and determining a groove spacing used to make a certain note on the roadway.



All in all, a very groovy activity. It was fun to originate and modify it so that it became a nicely laid out vessel for several related sound demos.

Science is Fun! Demonstration at The Book of Phyz
Jeff Milner's Backmasking Page (Paparazzi and Stairway are recommended; use Baby One More Time at your discretion)
Talkie Tapes
Music Box Mechanism
2009 Honda Civic Musical Road on YouTube

"Why I am not a Modeler" at Global Physics Department

We had a nice discussion on "Why I am not a Modeler" at Global Physics Department last night. Thanks toderator Andy Rundquist for helping me navigate the details of Elluminate Live. I was much less klutzy than I would have been otherwise.

As I mentioned in an earlier post, Elluminate is a highly interactive, kinetic chat interface. Some people have the requisite skills to present their talk while monitoring the chat feed. I am not such a person. But Andy was kind enough to jump in when questions arose.

As might be expected, the more "face-to-face" live nature of the GPD meeting resulted in a less contentious discussion than the comment threads that followed my original blog posts. I say that without judgment for or against either medium.

In any case, here is the GPD page for the recording of the meeting in case you missed it and wanted to see/hear it.

Global Physics Department 3/21: Dean Baird: Why I am not a Modeler

(Andy's title of "modeling smackdown" is more a use of colorful language employed with good humor among colleagues than it is an accurate description of my actual talk.)

Go straight to the recording!

Next time, I'll learn to scale down my Keynote preso to correctly fit into Elluminate's whiteboard space.

Two new activities for PhET's "Faraday's Electromagnetic Lab"

I've always liked the presentation of PhET's "Faraday's Electromagnetic Lab" sim, but could never figure out how best to leverage them in inquiry-based activities. And some might say that I have yet to overcome that challenge.

Nonetheless, I wrote two activities that—between them—allow for the exploration of the sim's capabilities. There's some good physics illustrated and animated in the sims.

Electricity and magnetism are difficult subjects for physics learners, so many hands-on lab activities are called for. No harm in adding a few virtual lab activities to the mix.

"Faraday's Electromagnetic Lab" sim.

"Faraday's Electromagnetic Lab I: Magnets and Electromagnets" activity and answer key.

"Faraday's Electromagnetic Lab II: Pickup Coil, Transformer, and Generator" activity and answer key.

These are "first-takes" and may benefit from further development at a later time.

Tonight on Global Physics Department

Me.

Global Physics Department > SITES I LIKE > Link to Global Physics Department Chat

"Why I am not a modeler"
6:30 pm PT - 7:30 pm MT - 8:30 pm CT - 9:30 pm ET