Thursday, December 04, 2014

I am the pot of gold!

We've been getting some much-needed sky-water in Sacramento lately, and the forecast promises even more. California is literally collapsing as we pump out the ground water the state sits on, desperate for precious H2O.

Our reservoirs remain low and we're still in a drought, but we inched our way toward normal with some nice downpours today. As the heavy weather moved eastward, a break in the clouds allowed the setting sun to poke through. And there I was with my iPhone.

Sunday, November 30, 2014

Dark Energy? No! It's A Crazy Pool Vortex!

Physics Girl's Crazy Pool Vortex

So many physics… What's not to love?

I like that the image in the poster frame bears a striking resemble to the FSM. Coincidence? Perhaps.

Wednesday, November 26, 2014

Bungee Jump Physics Extravaganza!

I hate to overstate the case, but this activity is a whole lotta physics going on. Terms such as "Wow," and Bidenisms like "Literally over the top" come to mind.

In July, I jumped off a bridge. On purpose. In Africa.

A video was recorded.

Victoria Phyz Falls

Physics happened, and I was keen to exploit the event as an analytical assignment for my students. Because that's how I roll.

But such exploitation was not a trivial affair. I undertook the jump as a tourist about as far from home as I could be on the surface of the Earth. Deep in the midst of a month-long African wildlife photo safari detailed on The Treks of Phyz blog. Not as a physics teacher at a nearby amusement park loaded up with sensors and synchronized high-speed videography gear.

So hard data was limited. Easily measurable quantities on the captured video were limited. Quantitative information from the vendor proved… unreliable (See the "All the Facts" tab here).

What follows at the link below is a six-page student activity that could be assigned as homework or completed as a "video lab" in class. As always when working with a YouTube video, I recommend downloading ("ripping") the video first. As a Mac user, I then use QuickTime to trim and study the video.

A shorter YouTube Baird Bungee video can be found here.

The lesson engages issues including force and motion, Hooke's law, conservation of energy, and simple harmonic motion, among other things. There's qualitative analysis, verbal interpretation, graphing, direct measurement from video, and robust quantitative analysis.

In short—there is no "short": This thing is a beast.

I felt compelled to ask for a consult from Dan Burns, AP Physics C master teacher, YouTube sensation, general brainiac, and a maestro of mechanics. To suggest he is the Maxwell to my Faraday inflates my stature more than it does his. He was kind enough to give it a very thorough going-over. Many thanks, indeed, Dan!

Dan's analytical approach differed from mine, but we ended up with the same answers. And we both recognized some sticky issues incumbent in the quantitative analysis of such a data-poor problem.

But enough of my jibber-jabber. The whole kit and kaboodle is available here (answer key included—that's the kaboodle).

Victoria Phyz Falls @ TPT.


Tuesday, November 25, 2014

Common Mythconceptions: a poster from Information is Beautiful

"The World's Most Contagious Falsehoods"

I paid the $5 to get the high-res version, and printed it out onto 22"x17 paper with my big Epson 3880 inkjet printer.

I posted it where students can see it from outside the classroom, and it's definitely got some flypaper attraction abilities.

Information is Beautiful's Common Mythconceptions

Some topics are intended for a more mature audience, so I don't recommend it for middle schools.

Sunday, November 16, 2014

FLIR One: A thermal imaging camera for your iPhone 5

The world is lousy with iPhone cases. They're available in all manner of designs to suite a wide variety of tastes and brand loyalties.

FLIR Systems has a $350 case for the iPhone 5/5S. It's a dual-camera thermal imaging system called FLIR One.

FLIR One is a battery case with two cameras whose lenses are in close proximity. One camera is sensitive to visible light, the other is sensitive to infrared light.When actuated, the two cameras collect images simultaneously. The FLIR One app processes the two images into one "thermograph" The app uses the visible light image to create outlines of hard edge boundaries of objects while the IR image is processed into false colors that fills the frame.


If I had an iPhone 5 or 5S, I'd be shooting the world with one of these things. I eagerly await a FLIR One for iPhone 6.

(FLIR is an acronym! Do you know what it stands for? I'll put the answer in the comments.)

Monday, November 10, 2014

Is inertia the truck driver's friend or foe?

The answer is: Yes!

First the classic. We love it, we know it, we rip it, we show it.

Shopping Cart Fail:

But inertia and Newton's First Law are not always your enemy. Some truck drivers make inertia their friend.

Taiwanese Bamboo Delivery

Tuesday, November 04, 2014

Groovy… but I won't show it in class

Except as a springboard to a discussion of "What did they do wrong this time?"

But it is groovy. The world's largest vacuum chamber is used to perform the a variation of age-old physics classic, "penny and feather" free fall experiment.

Brian Cox visits the world's biggest vacuum chamber - Human Universe: Episode 4 Preview - BBC Two

Here's a video clip that I do show in class: A hammer and a feather dropped on the Moon.

Feather & Hammer Drop on Moon

Brian Cox is many kinds of wonderful, but showing free fall in a vacuum chamber using high-speed (slow motion) video, alone, acts to deceive.

A common misconception among physics learners is that gravitational acceleration depends on atmospheric pressure. Things float in space because there's no air in space. There's no reason to think g in the giant vacuum chamber is 9.8 m/s2. All video of free fall in the evacuated chamber is artificially slowed. We never see the vacuum chamber free fall in real time.

The lesson could be interpreted that things fall more slowly in a vacuum. On Earth as it is in Heaven. Or the Moon, at least.

Sunday, October 26, 2014

And that's the week that was...

a strong contender for the craziest week at school in my 29 years thus far. I cannot divulge all the details here, and there's even more going on than what I'll document in this post. But even what's out there is enough.

It began Friday, October 17th with an impromptu student protest that I began hearing about through the student chatter between classes. News vans were on campus, media was being collected for news pieces later that day.

There had been an incident involving a student and an administrator. A physical altercation had occurred in the vice principal's office that involved the VP physically restraining the student. The student bit the administrator through the flesh. The students were protesting in support of the administrator-biter.

KXTV News10's slideshow:
Rio Americano students tape mouths shut in protest

At an optional, information staff meeting after school, we were informed about details of the protest and how it was handled by the principal. We also learned that some graffiti left in a girls' bathroom threatened a school shooting on October 22. October 22 was also the date of the school district's disciplinary hearing regarding the biting incident.

San Juan Unified School District's Threat Assessment Team was called into action, investigating the threat with the Sacramento Sheriff's Department. Eventually, the Federal Bureau of Investigations and the Department of Homeland Security were involved. Additional law enforcement personnel were brought on campus and teachers were asked to be out and about during prep periods.

By Tuesday, October 21, a note had been found suggesting the shooting had been bumped up to that day. There was apparently some absenteeism beyond what should be expected. The drumbeat of local news coverage served to amplify the drama.

Here's KCRA's contribution (Sadly, this reporter didn't really know where she was. "Rio Americana"? Really?): Rio Americano HS attendance drops after shooting threat"

And this from The Sacramento Bee: Rio Americano shooting threat leaves students, parents nervous

Not surprisingly, absenteeism was decidedly more pronounced on Wednesday, October 22. I went about my business as per usual. Teaching physics, as I do. With heightened awareness, but not with anything resembling a siege mentality.

Things were going smoothly until lunch. About ten minutes into lunch, the fire alarm klaxons and strobes began to fire. I presumed a student sympathetic to the biter was looking to make a splash on this day. Still though, the entire school population was mandated to proceed away from all shelter and out into the sniper-friendly open areas of campus on the day a school shooting was threatened.

The genesis of the alarm was not as I suspected. No, it was merely a colleague burning microwave popcorn during lunch on this—of all—days. One hopes he learned the importance of staying with the machine while the corn is popping. But I doubt it. His subsequent blog post is less an apologetic mea culpa and more a Nixonian, "You won't have me to kick around anymore"/"I'm taking my ball and going home" vibe.  This from someone fond of publicly referring to people of all walks as "idiots" and publicly calling others out for "incompetence". (I set off the school's fire alarm once, too. Here's my post on the matter.)

Clearing the alarm pushed lunch later, so our 6th period block period lost about 15 minutes of instructional time.

And on Thursday, some of the faculty officially played softball after school. [Rio's greatest video coming soon!]

On Friday, a local, tragic crime spree sent ripples throughout Sacramento and beyond. With police helicopters circling above, our principal came over the PA (for the third time this week) to announce that the overhead activity was not related to anything at Rio, but that we were now sheltering in place until further notice.

The shelter in place continued into lunch until 12:30pm. By then, I had volunteered to escort classes of students to-from the bathroom per shelter in place protocol. A group of parents had hoped to have a donut-filled celebration at lunch to mark the passing of the stressful week. With lunch being forestalled, donuts were shuttled to sheltering classrooms. The events that precipitated the shelter in place at dozens of schools made national news.

With nerves sufficiently rattled school-wide and many minutes lost—this time from the afternoon classes, I moved tests scheduled for the afternoon (AP Physics 1 and AP Physics 2) to Monday. On-the-spot lesson-shuffling was implemented so that minimal instructional time was lost.

My take?

Through it all, the school's administration handled things with calm aplomb and laudable professionalism. This in the face of what appear to be the aberrant claims of a misbehaving student and her mother, a misguided student protest, vulturing local news media, and other obstacles. Based on what I know, I have no reason to suspect that the administrator involved will be found at fault of any misconduct whatsoever.

I hope none of my colleague's stayed away from school October 22. I was disappointed that so many students did. An abundance of law enforcement was brought to bear on the situation, and they did not find the threat to be credible. Keeping students away from school that day allowed the graffiti-author to have a disproportionate disrupting effect. Running in fear from every emotional outburst generated by teenagers in a high-school community gives undue power to individuals who clearly should not have it.

Ad infinita:
rio americano tumblr
Principal's Message 10/24/14

Sunday, October 19, 2014

Captain Disillusion - Viral Videos

Captain Disillusion gets his Cosmos (NdT version) on, with nice references to his previous Tumba debunk, outlawed magnetic Buckyballs, and magnet boys.

Captain Disillusion - Viral Comets Truck Saves Plane

"The Laws of Attraction" — A new PhET sim-based lab

This activity is a fairly deep exploration of the elements of Newton's Universal Gravitation. In the "Gravity Force Lab" sim, the force between two masses is displayed. Both masses can be changed, as can the distance between them. Mathematical patterns are developed and cobbled together until the full universal gravitation proportionality is constructed.

My lab activity, "The Laws of Attraction" can be found here.

PhET's "Gravity Force Lab" sim can be found here.

Here's the sim as it can be embedded:

Gravity Force Lab
Click to Run

Conceptual Physics PhET Tech Labs

The webpage that organizes my PhET sim-based labs had been updated significantly.

There are now 15 Conceptual Physics Tech Labs that employ PhET simulations. Check them out:

Phyz PhET Labs

The sim-based Tech Labs run the gamut from Mechanics through Atomic and Nuclear Physics.

Sunday, October 12, 2014

Circuit Scribe

Sometimes something floats up through the Facebook feed that is fairly groovy, and I ponder, "Why didn't I already know about this?"

For example, Circuit Scribe. I've seen conductive-ink pens before, but it seems you needed special pepper. Circuit Scribe needs proprietary components, but still appears promising.

And it looks like they met their Kickstarter goal so I hope to see these things in the world sometime soon.

Sunday, September 28, 2014

New AP Physics 2 resources on fluids in The Book of Phyz

The Book of Phyz page on fluids has been up for some time:

Book of Phyz: Fluids

Two new "phyzjobs" have been added: "Liquid Pressure" and "Buoyancy Overflow."

And there are fresh links to the full pages for two fluid PhET sims:



I've posted labs to those PhET pages.

Pool Cubes - Density and
Pool Cubes: Buoyancy 

The blogging may run light this year while I try to get AP Physics 1 and AP Physics 2 launched at Rio Americano. Apologies.

Monday, September 01, 2014

The Book of Phyz online reorganization and upcoming changes

With NGSS, AP Physics 1, and AP Physics 2 coming online, our physics course offerings at Rio Americano are changing. The Book of Phyz is being reorganized to match Rio's courses.

If you're an instructor who's found The Book of Phyz materials to be helpful, they're all still there.

Please start at, then proceed to the curriculum materials via the "Physics," "AP Physics 1," or "AP Physics 2" links.

The documents are organized so that I can make them easily accessible to my currently-enrolled students. That was the point of posting them to in the first place.

I'm planning to phase out the posting of the lab handouts that have been published in Paul Hewitt/Pearson's various Conceptual Physics, Conceptual Physical Science, and Conceptual Integrated Science lab manuals.

The best collection of my labs is the newly published Conceptual Physics 12th edition Hewitt/Baird lab manual, discussed in this post. Hewitt's 12th edition of the college book is the best yet, and the lab manual aligns to it quite nicely. If we were adopting textbooks this year, I would adopt Hewitt's CP12 with the more durable high school (NASTA) binding.

Sunday, August 17, 2014

How the Sun Sees You

I found this video to be totally captivating. The message is an important one. But the soundtrack is also nice. And then… how did they record this? See for yourself.

I love the "Oh My God!" moments. The appearance of the sunscreen didn't surprise me. We try to incorporate the opacity of sunscreen in our ExploratoRio Purple Haze exhibit. What I came away really wanting to know was… how can I set up a similar rig to capture live video in UV? Cameras with glass optics and glass filters and glass over their sensors are well protected against ultraviolet light.

The Exploratorium's Paul Doherty shared this informative Photonics article.

Ultraviolet Reflectance Imaging

The article mentions fused silica optics. Paul recalled grinding sodium chloride lenses for use in UV imaging. Fused silica and salt lenses? My ignorance is so vast, sometimes it hurts.

Here's a video tutorial on getting a DSLR modified and configured to shoot in the UV range. It's, well, a nontrivial affair.

Thursday, August 07, 2014

Saturday, August 02, 2014

Planning the year: NGSS, AP1, and AP2 - Part 1: The broad strokes

My assignment for the 2014-15 academic year includes Physics, AP Physics 1, and AP Physics 2. The Physics course should be aligned to Next Generation Science Standards. Our students are years from facing NGSS assessments; right now school officials of nearly every stripe are focused on Common Core State Standards nearly to the exclusion of any other academic concern.

Last year marked my first attempt to let go of the past decade+ focus on California's now-abandoned academic content standards in physics.

Advanced Placement Physics 1 and Advanced Placement Physics 2 debut this year, and Rio has enrollments in both. Now that AP Physics B is dead and gone, The College Board is laying the AP1 and AP2 cards on the table. My friend, Chicagoland physics teacher extraordinaire, Martha Lietz, pointed me to her AP Physics resource page. And I have been poking around in the links!

This post will give a general direction of how I plan to implement the three courses at my school.

Physics remains a first-year course with an Algebra 1 prerequisite. It needs to fulfill the needs of NGSS as well as provide a suitable foundation for students who might elect to move onto AP Physics 2. It is not feasible to allow Rio's pipeline to AP2 be restricted exclusively to AP1 "alumni".

AP Physics 1 is a first-year course for highly-motivated students who have passed Algebra 2. It must cover the AP Physics 1 syllabus provided by the College Board. But it must also cover the expectations of NGSS.

AP Physics 2 is a second-year course for highly-motivated students who have passed Algebra 2 and a first-year physics course (Physics or AP Physics 1). It must cover the AP Physics 2 syllabus provided by The College Board.

In any case, here's my plan so far. Click to embiggen. Subject to change!

And yes, I'm willing to try the current fashion of energy before momentum. Wide ties/narrow ties. It seems that among the cognizanti, teaching momentum before energy is on par with wearing a wristwatch or typing two spaces after a period as far as age indicators go. I know there are strongly-held beliefs, arguments, and preferences here. Sometimes I think we get too exercised about such things.

In good company

The American Association of Physics Teachers formally unveiled its Fellows program at the Awards session of its Summer 2014 meeting at The University of Minnesota in Minneapolis.

Generally speaking, previous AAPT award winners were inducted as the Inaugural Cohort. I was a recipient of their Distinguished Service Citation in 2008. And that's how I came to be included on a list of physics-teaching heavyweights. It's true, I have an ego the size of Montana, but I'm also grounded enough to know I'm dwarfed by the giants on this list.

AAPT's Fellows Announcement Page
A List of the Inaugural Cohort

Thursday, July 31, 2014

AAPT SM14: Physics Force selected moments in high speed

The Physics Force provided the demo show for AAPT's Summer Meeting 2014 at the University of Minnesota in Minneapolis. I caught a few moments at 120 fps in HD and posted the compilation to YouTube.

Physics Force AAPT SM14

Sunday, July 27, 2014

My AAPT SM14 photo album begins

Most images are from Sunday's High School Share-a-thon at The American Association of Physics Teachers Summer Meeting 2014 (AAPT SM14) so far.

Monday, July 14, 2014

Yellowstone lightning strike caught on video

The lightning grounded through a tree and the voltage remained high through the conductive root structure. The heating of the surrounding (less conductive) earth was rapid and intense, resulting in what look like explosive pop of soil.

Click to link to the video
(Oh Yahoo News, why must you annoy me so?)

Lightning strike caught on camera at Yellowstone National Park - Lonewolf Sager

Enjoy the curious stat about lightning strike "gender bias". Oh, the original item mentioned that more men than women are struck by lightning. I'm guessing that male golfers are overrepresented among lightning strike victims.

Friday, July 04, 2014

I was bound to do this

So there I was at Victoria Falls, on the border between Zimbabwe and Zambia. The Victoria Falls Bridge spans a gorge through which the Zambezi river runs, post falls. We are told the deck of the bridge is 135 meters above the water.

At the midpoint of the bridge there is a low-slung hut through which bungee jumpers are fitted with harnesses and pushed over a precipice. We are told the bungee jumpers plummet 111 meters, though it seems the mileage would vary from one jumper to the next, depending on weight.

I'm much too bashful to reveal my weight, but the bungee operators wrote 111 on my arm after having me stand on a scale. Oh yeah, I signed up for this jump. I teach physics! I was bound to do this.

They harness you quite thoroughly, and cinch your lower calves to each other and attach them to the bungee cord with five carabiners. I was bound to do this.

They help you waddle out over the lip of the diving platform. Then it's "5-4-3-2-1-BUNGEE!" and off you go, into the gorge. But enough jibber-jabber. Let's roll the film.

Victoria Phyz Falls

Was I ever really in danger? As it turns out, yes I was. This very jump dropped an Australian woman into the Zambezi a few years back.

Aussie Tourist's Bungee Cord Snaps

I really only put myself at risk like this so that Dan Burns could generate some nice, personalized physics problems, if he is so inclined. If you think of some, leave them in the comments or email them to me.

Did I mention that I jumped off a bridge?

My African media shoeboxes

The month-long African safari is in progress!

Lightly-processed safari photos are accumulating on Flickr:

Accommodations and other random shots are accumulating here:

Videos are accumulating here:

The blog at Outdoor Safari Photographers. I was/am with them June 16-20 (Machaba), June 28-July 2 (Chobe/Pangolin), and July 5-9 (Elephant Plains).

Further details when I return.

Saturday, June 14, 2014


Jolly? Sometimes. Good? Depends on who you ask.

Fellow. Most indubitably.

At least I will be, as of the American Association of Physics Teachers (AAPT) Summer Meeting 2015.

More details will no doubt emerge at the meeting. But it appears that AAPT is assembling a cadre of honored individuals and bestowing the title of "Fellow" upon them. The AAPT honored me in 2008 with their Distinguished Service Citation. And as I continue to be a member in good standing, I have been included in the first cohort of this cadre.

There will be some manner of shindig exclusive to AAPT Fellows at the Summer Meeting, and we are invited to add the honorific of "F.AAPT" or Fellow, AAPT" after our names on correspondence.

In any case, it's a delightful honor and I am humbled to be in such austere company.

Dean Baird

Monday, June 09, 2014

Tower of paper

Our end-of-year schedule included an amusing burp this year. It came on the last Thursday of the year. Students in periods 1-4 had already had their final exams on Tuesday and Wednesday, and students in periods 5 and 6 would have their final exam on Friday. All students in all classes met on Thursday.

What to do?

Give each lab group a single sheet of colored 8.5"x11" paper, a pair of scissors, and a table-width length of masking tape (about 2 feet), along with the directive to use those materials to construct a free-standing tower of maximum height.

Only the paper and the tape could comprise the tower (not the scissors). The tower has to stand for 5 seconds while its height (from the table top) was measured. The tower had to stand freely on the table (not taped down; not suspended from the ceiling or dropped outlets). Each group is given a distinct color of paper, no two are the same. (This helps with the integrity.)

One point of extra credit was to be awarded for every full inch of the tower's vertical height.

Our tallest tower this year was 57 inches tall. (I conjoin two meterstick/yardsticks and sometimes need to stand on a chair to get the measurement. I also turn off the HVAC) In the past, I believe the tallest tower we've ever had was 63 inches. Not bad for a single sheet of letter paper.

The students tend to be motivated, and it was a great activity for an otherwise throwaway day. And it's photogenic.

2014 05 Tower

Saturday, May 31, 2014

Rio Phyz 2014: Class Portraits

Some with flash; some without. Some with teacher; some without. Some straight; some goofball. The whole set can be accessed via this Flickr Set:

2014 05 Rio Phyz Class Portraits

UPDATE: As per usual, Flickr sent the original album into the æther somehow. I re-uploaded the whole thing. I can't imagine relying on Flickr as a backup of any sort. Photo links often degrade faster than a fine pastry, and albums once loaded can easily disappear for no apparent reason.

Friday, May 30, 2014

ExploratoRio 2014 - The Video

Directed and produced by student videographer, Grant Webster. Laugh, cry, relive the memories!

ExploratoRio 2014

Sunday, May 25, 2014

Outdoor activities for oddball days

A request was made (via our PTSOS discussion group) for outdoor activities that might be fun during weird days that seem to crop up at the end of the school year.

The ever-resourceful Los Gatos physics teacher and PTSOS leader, Dan Burns, suggested the following.

I like stomp rockets. Measure the distance to the launch, the angle it makes at apogee to the horizontal, calculate height. Measure time in air, calculate height and initial velocity.

Make pinhole cameras and use them to determine the diameter of the Sun.

Get in a line and spin in a circle. Each student calculates their angular and linear velocity.

Bang a drum twice per sec, students walk away until they hear the sound at the same time the drum is hit. Measure that distance, divide by 0.5 to get the speed of sound.

Make water balloon launchers out of surgical tubing. Calculate the force constant, the elastic potential stored, predict initial velocity and time in air if launched vertically. Then predict max range.

Have students push a car on a flat surface using bathroom scales. Drop beanbags at regular time intervals. Measure acceleration of car using the force applied and mass, compare to acceleration derived from pattern of beanbag separation.

Perform Herschel's experiment that detected IR radiation using glass prisms and thermometers.

Jump rope generator, rotate loop of wire like a big jumprope that is hooked to a galvanometer. See it generate current using earth's magnetic field. See Conceptual Physics Manual.

Sunday, May 18, 2014

NGSS is a Renaissance, not an Upheaval for Physics Teachers

Your use of the word upheaval is overly sensational. According to Webster's, upheaval means: "a major change or period of change that causes a lot of conflict, confusion, anger, etc.". This characterization would only apply to AP Physics B teachers, a small subset of high school physics teachers (and now a null set!). As for NGSS, I would use something like "freedom", "autonomy", or even "Renaissance". Unlike previous top-down efforts to shackle professionals to a checklist of factoids, this set of standards is more about the process of teaching students how to think and use information to understand the world they live in. There is a large degree of freedom given to teachers to determine how they want to approach achieving the NGSS. NGSS is very similar to the approach outlined in decades-old documents like the Project 2061 "Benchmarks for Scientific Literacy" and the 1991 California Science Framework. It is the pendulum swinging back to a better time in physics teaching. If you rely on your professional judgement as to what constitutes good physics teaching practices, you will not have to worry very much about adapting to NGSS.

Even if you are a teacher that is experiencing "a lot of conflict, confusion, anger, etc." regarding NGSS, I say relax and enjoy the next 2 school years without worrying about preparing your students for state-mandated tests. The earliest these could return would be the 2015/16 school year and the people I work with that are more involved in this process expect them later than that. This is from the FAQ page on NGSS for California:

"When will there be new assessments for the NGSS?
The earliest new science assessments might be available is the 2014–2015 school year. However, due to the short timeline, new science assessments will most likely not be available until the following school year.

Will Smarter Balanced Assessment Consortium (SBAC) have science assessments for NGSS?
At this time, new science assessments will likely be developed much like the assessments of SBAC . However, it is still too early to know exactly how and when new science assessments will be administered.

In SSPI Torlakson’s report Recommendations for Transitioning California to a Future Assessment System, Recommendation 4 encourages the development of new state science assessments consistent with the newly adopted NGSS for California, that include item types consistent with the SBAC assessments (e.g., short and extended constructed-response items and performance tasks)."

The full list or FAQs can be found here:

I suggest they dig up the old Golden State Exams for Physics and complete this retro cycle!

Dan Burns
Los Gatos High School

Friday, May 16, 2014

Hewitt Fest 2014 at Rio Americano

Conceptual Physics author, Paul Hewitt, was in Sacramento for a day so he could attend Pasco's 50th anniversary. (I was fortunate enough to be able to attend the event, which was great fun in celebration of an excellent company with solid corporate values.)

Hewitt, along with his delightful wife Lillian and ever-clever Evan Jones, was kind enough to drop in on my Physics classes today. He regaled the students with tales of the inverse square law, sunballs, college matriculation, and his path to physics.

After the lessons, the lunch time bell rang and my room became Groupie Shot City (or Selfie Central). My post to Facebook was, "An 82 year old textbook author visited my school today. The students mobbed him like he was a rock star."

Here are some images to prove it.

2014 05 Hewitt Fest at Rio Americano

Some readers might recall that Hewitt paid Rio Americano a visit on the last day of school, June, 2011.

Sunday, April 27, 2014

NGSS? AP1? AP2? What physics is covered where?

Here's my first blush attempt to sort out the scope of each flavor of non-calculus high school physics.

One thing I will say about the new AP Physics 1 and AP Physics 2 is that they are intentionally, deliberately de-emphasizing the notion of content. They've never wanted to really spell out, in detail, the specific topics covered in each course. The College Board is keen to talk for days about the emphasis on inquiry and big ideas. They seem keen to relegate the physics content specifics to the canvas on which inquiry and big ideas are painted.

The old AP Physics B course description detailed the content coverage down to percentages. The new AP Physics 1 and AP Physics 2 course descriptions mention physics content as if specific topics were but an afterthought. Check out the two-page executive summaries of AP1 and AP2 and see hope much ink is devoted to identifying physics content.

In any case, I did a "back of the envelope" style stream-of-conciousness layout of physics content topics and where—if at all—they are covered in the upcoming NGSS, AP1, AP2 scheme. The green, checked topics are, in my estimation, explicitly called for. The yellow, slashed topics are implied (or, more correctly, inferred by me).

Others may object to my topic list. Ro each, his/her own. Others may read the NGSS, AP Physics 1, and AP Physics 2 descriptions differently. I may read them differently by this time, next year.

Keynote conversion: Phase 1 complete

As mentioned previously, I'm converting the curriculum material I've written over the years from Canvas documents to Keynote documents.

Just before 10pm last night, I completed Phase 1 of this project. All my Physics 1 documents are now converted. This was an important milestone to exactly me. The Phyz Springboard: Understanding Rainbows was the last to be rebuilt. All tolled, over 200 documents were reconstructed. Most were two pages, a few were only one, but many were three or more pages. I don't know exactly how many pages had to be rebuilt, and it's probably better that way.

Work has already begun on Phase 2: AP Physics B (now AP Physics 1 and 2). But there are miles to go before I sleep on that. Completing Phase 1 took the better part of two years. If all goes well, Phase 2 will be done sometime in 2016. I'll need my aging MacBook Pro (2008, Mac OS X 10.6 Snow Leopard) to hold up through then, since my newer MacBook Pro (2012, Mac OS X 10.8 Mountain Lion) does not have Rosetta and so cannot open Canvas X.

The seaworthiness of my lifeboat, Apple's Keynote, has been cast into doubt by Apple's dramatic botching of Keynote 6. It appears that Apple really doesn't want to author software anymore. As a matter of pragmatism, I'll need for Apple to fix Keynote (unlikely), or at least allow for the continued operation of Keynote 5 for another 10 years (not likely). Both of those are tall orders.

Here's where the Canvas X to Keynote 5 stand now. (Green means a section is complete, orange means a section is down to a fewer than 4, yellow is fewer than 2.) (Also in the interim, California's 9-12 Physics CST has been discontinued and NGSS is being adopted. To wit, the unit on heat and thermo is no longer part of our first-year physics class.)

The punchline? After killing Canvas for Macintosh in 2007, ACD claims they are developing Canvas for Macintosh in 2014. At this point, I don't trust them, and I wouldn't put it past them to develop Canvas 15 for Mac as a app that either cannot open Canvas X documents or will scramble such documents upon opening them.

Monday, April 21, 2014

ExploratoRio 2014 Photo Album 1 - The DB Set

Here are a few shots that I got while hosting ExploratoRio 2014 on April 9. More photos should be coming soon. This is but a start.

2014 04 ExploratoRio

Wednesday, April 16, 2014

AP Physics at Rio update

We didn't have AP Physics B this past year. Enrollment sign-ups were insufficient for the school to run the course.

Recently-revealed evidence suggests that the dearth of sign-ups might have been related to the grading practices followed by colleagues who teach AP Biology, AP Chemistry, and AP Environmental Science. The case was laid out in a previous post.

Students have now signed up for their Fall classes. I have been informed that there is sufficient enrollment for the school to run both new AP Physics courses: AP Physics1 and AP Physics 2, in addition to three sections of Physics.

It's the "nightmare" I hoped for: three different courses to prepare ("three preps" as we say in the faculty lounge). AP Physics 1 and AP Physics 2 are brand-new, never-been-taught courses, so it'll be like seating thread-forming screws. To make matters worse, I intend to redesign our Physics course, aligning it more closely to Next Generation Science Standards and to our adopted textbook.

Here's some information on the new AP Physics 1 and AP Physics 2 courses being launched in 2014-15.

Friday, April 11, 2014

ExploratoRio 2014 Night

Here is the conclusion of this year's ExploratoRio time lapse series. We see the 90-minute exhibition and the 60-minute striking of the set. In the end, the classroom has returned to its original state and is ready to go for the next day.

ExploratoRio 2014 Night

Wednesday, April 09, 2014

ExploratoRio 2014 Daytime

To be a bit different in this year's time lapse, I toured the camera around the room before setting it back on its perch. I also took it outside and into the dark room. A white balance (set to the fluorescent light of the classroom) penalty was exacted.

Earlier, I relearned the lesson that my wide-angle lens is, in fact, a manual focus lens. And easily jarred when the camera is moved, the battery is changed, and the memory card tinkered with. Life goes on.

Here's today's clip. ExploratoRio 2014 had been going for three hours by the time this clip began rolling. So we see things through to the end of the daytime portion.

We had 12 elementary classes come to visit, so that's about 12 x 30 = 360 little ExploratoRions. I hope to see them again as students a few years from now.

ExploratoRio 2014 Daytime

Tuesday, April 08, 2014

ExploratoRio 2014 room prep and exhibit setup

From 3pm to 5pm, we ready the room. From 5pm to 6pm, the exhibits come in. Here's what it looks like, shot at 1 fps, displayed at 30 fps.

ExploratoRio 2014 Room Prep and Exhibit Setup

Monday, April 07, 2014

Some high-speed video from NSTA 2014 Boston

The 2014 NSTA conference was held last week in Boston. A few clips of high-speed video were made available to us, so we present them here.

Frisbee Dogs
There was a session on using Frisbee-catching dogs in the physics curriculum. Some ask "Why?" The answer is that there are people out there who love physics and love dogs, so they brought their passions together. In any case, they also brought a dog to the Boston Event and Convention Center.

Frisbee Dog (HD at 120 fps)

Pasco's Annual "Just Physics" NSTA Demo Show
The good people at Pasco once again staged their "Just Physics" demonstration show. David Maiullo assembled his blue-ribbon crew: Sam Sampere, David Sturm and Borislaw Bilash II. "Just Physics" always draws a big crowd, and serves as a welcome refuge for any physics teacher overwhelmed with all the non-physics going on at the conference. Pasco provides food, T-shirts, and resources for a first-rate show.

There were too many demos in the 90-minute show for anyone to capture them all. And not all of them lent themselves to high-speed video.

Ping Pong Bazooka
We'll begin with a clip that reveals challenges to the demonstrators and to the videographer. The Ping pong bazooka is now well-known among high-end physics demonstration professionals. But it can be finicky, and it doesn't always perform well under, uhm, pressure. The camera being used is a Panasonic Lumix DMC FZ200. It's capable of high-speed capture at 240 fps (VGA) and 120 fps (HD). The camera also sports a telezoom lens whose focal length can be extended to the equivalent of a 600 mm lens with an aperture of f/2.8. While the lens features image stabilization, going to full zoom challenges the IS system.

Ping Pong Bazooka (VGA at 240 fps)

Ping Pong Explosion
We move on to the Ping Pong Explosion. A plastic waste can has a bit of water at its bottom. A small, empty, plastic soda bottle is partially filled with some liquid nitrogen then capped tight. The bottle is tossed into the can and immediately covered in hundreds of Ping Pong balls. This part needs to be executed with some haste. The liquid nitrogen boils as the liquid turns to gas. But the gas requires much more volume. And that volume is not available in the small soda bottle. So this happens:

Ping Pong Explosion (VGA at 240 fps)

Liquid Nitrogen Cloudburst
In out final high-speed clip, we see what happens when a cooler of liquid nitrogen is doused with a bucket of water.

Just Add Water (VGA at 120 fps)

Sunday, March 30, 2014

Laboratory manual for Conceptual Physics 12th edition

Things have been quiet here at The Blog of Phyz. Too quiet. That's because I've been assembling, remastering, and authoring the laboratory manual for Conceptual Physics 12th edition with Paul Hewitt.

We've got an ISBN of 0321940059. We've got a page at Pearson. Here's my exciting preview of what it should look like.

The table of contents can be found here. It reveals two things:

1. There are 16 new labs added since the 11th edition CP Hewitt/Baird lab manual.
2. This manual plays nicely with Hewitt's 2009 high school Conceptual Physics textbook, too.

If all goes according to plan, the manual will be available for Fall 2014. But yes, this kind of project, together with ExporatoRio Season and Advertising Season (which I would have posted about if not for the busy-ness) and other goings on… has kept my chatter down here at the blog. It will pick up again soon enough, no doubt.

Saturday, March 08, 2014

ExploratoRio season is in full bloom

Gratuitous time lapse of this year's exhibit adoption. Special thanks to Britknee for being such an excellent bouncer/door guard.

2014 ExploratoRio Exhibit Adoption

The "season" runs from the close of Presidents' ("Ski") Week until ExploratoRio (Open House). Exhibitors bring their exhibits in to show me that they work. Or I show them how to use school equipment to set up their exhibit (so they'll be able to do it on their own on ExploratoRio Eve). We discuss the operation, logistics, physics, perception.

I schedule one or two exhibits after school each day during the season, with the exception of Thursdays and other known blackout days. (Thursdays are out due to district-mandated "collaboration".) The one-on-one time with each set of exhibitors pays dividends on ExploratoRio Eve and Day in terms of operational smoothness and crisis avoidance.

Support staff positions are filling up nicely. Elementary class hosts are bringing in teacher contact information, and I've laid out a visitation schedule. We have three time slots yet unclaimed (two them being 11:30am-12-30pm). There are times when the space we have gets a bit crowded. We want to get as many elementary class students as we can to come in for a visit, but we have school for only a minimum day, so there is a hard time limit. One solution, I suppose, would be moving ExploratoRio off of Open House. But the original vision of ExploratoRio was for it to be the Open House activity.

Friday, February 14, 2014

Doing AP science wrong

I've taught AP Physics B since 1986. The course I taught was always intended to be an excellent advanced high school physics course that would compare as favorably as possible to an introductory college physics course. Engaging demonstrations and robust lab work was always important. But in the end, students needed to be prepared for the College Board's Advanced Placement Physics B Examination, administered each May.

From 1986 to 1997, we ran it as a first year course. But it was supposed to be a second year course, and in 1998, we brought our course into alignment with College Board expectations.

In recent years, sign-ups for AP Physics B dwindled at my school. Not so for AP Biology. Nor for AP Chemistry (which is a harder test than AP Physics B, as far as I'm concerned). Last year we introduced AP Environmental Science. It blossomed from one section last year to two this year. Impressive growth. While AP Bio and AP Chem held there ground, AP Physics bit the proverbial dust. Enrollment for 2014 did not merit a single section.

It was hard to observe the demise without concluding that the instructor of the course (that would be me) was doing something wrong. Data provided by the school's administration today sheds light on the subject.

In 2013, I had 25 students in AP Physics B. Only 21 sat for the exam, an unusually low test rate for me. Still though, while 16 of my students earned an A or B in my class, 16 also earned a 5 or a 4 on the exam. Six of the 21 AP Physics B examinees earned 5s. All my examinees passed with a 3 or better. I am rightfully very proud of all of them.

What I didn't know until today was that my raw number of 16 4s and 5s represented better top-tier performance than was had in any other AP science course at my school (including one with over double my enrollment). Or that my six 5s outnumbered the 5s from all our other AP sciences combined.

I also didn't know that my rate of classroom grades of A and B (64%) was—by far—the lowest rate, as was my A rate (under 50%).

AP and honors courses enjoy weighted grading in my district, so an A gets you a grade point of 5, a B a 4, and a C a 3. Where I grew up, a GPA of 4.0 was the mark of academic perfection. My students routinely have GPAs well above 4.2. Students hoping for admission to elite post-secondary institutions are keen to fly their GPAs into the stratosphere. Such students try to enroll in as many APs as possible. But with so many demands on their time (and many are in our nationally-recognized band program), meeting the academic rigor of an AP science course can be challenging.

The story of my AP Physics B's demise can be found in the data that follows. To me, the tale jumps right off the page. If it doesn't to you, interpret that as me overreacting; making a mountain out of a molehill.

The diminishing enrollment in my course amid the flourishing enrollments of my colleague's courses does suggest that someone is doing AP science wrong.

Here's the data:


In AP Physics B, there were 11 As and 6 5s. There was insufficient enrollment to run the course in 2014.

In non-physics AP sciences, there were 82 As and 3 5s. Enrollments in these courses increased in 2014.

A riddle wrapped in a mystery inside an enigma? I think not.

UPDATE: Is it important that course grades given by high school teachers be accurate and valid? Very much so. Colleges are increasingly valuing classroom grades over SAT/ACT scores.

Scientist Valentines: The Movie

Physics teaching colleague, Alex McKale of Stanford OHS, has turned the Scientist Valentines into a video, complete with a lovely physics-song soundtrack. Check it out!

Physics Valentines

Tuesday, February 11, 2014

It broke yesterday, and they don't really make them anymore

I use it nearly everyday at school for one reason or another. It comes in handy in a pinch. Mine was a gift from Paul Hewitt when he was moving out of his residence in San Francisco in 2003. He had used it for years, and I used it for a decade beyond that. (And I'm pretty sure I used it more heavily than he did.) It ran through consumables at a reasonable rate, but procuring them when needed was never a problem.

But it stopped functioning correctly yesterday, and it will be difficult to purchase a replacement. When I got it, replacement would have been a simple matter of a visit to OfficeDepot or OfficeMax. But this device appears no longer to be made. Market forces have driven this species to extinction in the past few years.

What was it?

It wasn't an electronic wastebasket. No, those things occupy a substantial amount of space at the big box office supply chains. I'd have my choice from dozens of models if it were an electronic wastebasket that I needed. Electronic wastebaskets are big right now, and the segment appears to be growing. There is a bonanza in electronic wastebaskets. Feel bad that you didn't get in on the ground floor.

It wasn't an adding machine. No, those seem to be doing just fine. If my adding machine went down, I'd have models to choose from on the shelf in the store today. The adding machine is far from obsolete.

The land-line telephone? No. Those are available in every shape and size. Land-line phones command considerable shelf space these days.

Fax machine? The 1980s live on! If I were in the market for a new fax machine, I'd have to comparison shop between multiple competing models.

Digital frame? You thought they were gone, but there are still models to be found on the shelves at OfficeDepot. Note the electronic wastebaskets nearby. This was a standalone display, more than 30 yards away from the main electronic wastebasket show space. It's quite clear that if you don't have an electronic wastebasket, you really must get one. The selection available on the showroom floor is breathtaking.

Was it my typewriter ribbon? No. The stock of typewriter (and printer) ribbons is well maintained at the modern office supply chain. I will include a link to the Wikipedia entry on typewriter ribbon for the benefit of my younger readers.

No. The long-laboring device whose utility has not yet diminished from my daily life is the personal photocopier. Paul Hewitt gave me a well used Canon PC740 in 2003, and I used it well until yesterday. Yesterday it made a plastic gear-gnashing sound upon power-up. It made several good copies before fading to black. Literally. The copies it made in the midst of a run got darker until the machine produced only toner-filled black tiles. The scanning tube remains as bright as ever, but black is all that comes out.

You can argue that the era of photocopying is over. Today's documents are electronic. Paper is the past!

But don't tell that to the stores that no longer sell personal photocopiers. Substantial volumes of these warehouse stores are devoted to photocopying services.

And don't tell that to school teachers. The photocopier is the most heavily used piece of office equipment at the school. We've never had fewer than two high-volume machines on campus, with low-volume units spread hither and yon.

I suppose I'm just having an Andy Rooney ("This modern world of yours is crazy!") moment. Perhaps I'm simply jarred because the predicament was unexpected. I used the machine and expected to buy a replacement when it died. But I can't. At least not easily.

The invisible hand of the market is telling me, in no uncertain terms, that I would be wrong to want a personal photocopier. The device is not useful in today's world. Not like typewriter ribbons, digital frames, adding machines, fax machines, and land-line phones. Those things are now! They are the U2s of office machines. Personal copiers? Destiny's Child.

I know there is no arguing with the flawless reasoning of The Market. I'm just too dumb to know why I can't readily buy a photocopier, but there is no end to suppliers eager to sell me toner for a long-since discontinued photocopier.

What I clearly need to do is to replace my broken copier with today's office machinery rock star: the electronic wastebasket. It is clearly the Bruno Mars of productivity devices; it could literally shred the gnar!

Friday, January 31, 2014

Faraday Cage: AM vs. FM

To demonstrate the fact that electric fields (unlike gravitational fields) can be shielded, I have taken to showing the effects of a Faraday cage on radio signals. (I wonder how many more years I'll be able to perform this demonstration this way.) I use a transistor radio as my "field detector" and a metal colander and a metal splatter screen as my blockers.

In serendipitous monkeying around, I noticed that FM signals "behave" better for this demonstration than AM signals do.

The FM seems impervious to being placed on the screen or in the colander. But when encapsulated, it virtually drops to nothing.

The AM signal, on the other hand, is sensitive to being placed in the screen or in the colander. But the signal remains intelligible even when the radio is fully encapsulated.

Take a look.

Faraday Cage AM FM

ExploratoRio 2014: The 20th Anniversary Begins

Today the exhibit recipes were posted. I plan to adopt them out prior to the Presidents' Week break.

ExploratoRio 2014 Exhibit Recipes Posted

For more on ExploratoRio, see
ExploratoRio Resources.

Thursday, January 16, 2014

Balanced Balloons - a new Figuring Physics

I am delighted to have developed some "Figuring Physics" ideas for The Physics Teacher columnist, Paul Hewitt over the years.

If you want a treasure-trove of Hewitt's "Figuring Physics" (a.k.a. "Next-Time Questions"), you're in luck.

Hewitt's Next-Time Questions at Arbor Scientific

We're in the midst of our study of electrostatics. Usually this brings torrents of rain to Northern California. This year's drought seems to be impervious to my machinations.

In any case, this little puzzle came to mind. It was preceded by the developments of Balancing Charges 1 and Balancing Charges 2 PhyzJobs. But I turned the concept into a standalone puzzle.

We begin with two helium-filled balloons that, when oppositely charged, are exactly balanced. They are attached to a massless bar that has a frictionless hinge at its midpoint.

I'll post the answer in the comments next week. It's a fun one to think through. Maybe it will make the cut for next year's round of "Figuring Physics."

Dan Burns updated his Science on The Simpsons page

From Dan:

"Hello Science on the Simpsons fans, I have added 13 more clips to the website. I included more biology related ones so share it with your life-science colleagues. Don't worry, there are some new physics ones like "Faster than Sound" and "Black Hole 1 and 2". The new clips start with "Acid Rain" in the right column:

Science on The Simpsons

Remember these are for educational purposes only.

Dan Burns
Los Gatos High School"

Go take a look. But be warned, you may find yourself binge-viewing the clips!

Sunday, January 12, 2014

The new adventures of old Star Trek

Did you know about this and not tell me?

Star Trek Continues E01 "Pilgrim of Eternity"

Jimmy Doohan's son playing Scotty? Marina Sirtis as the ship's computer? Nichelle Nichols guest appearance?

It's certainly not J.J. Abrams' Star Trek. And I count that as a plus, as I've seen about as much emotion splashing out of Zachary Quinto's Spock as I care to.

This holds true to The Original Series' aesthetics and sensibilities, for better or worse. And I'll apologize right now for the hour you're about to lose watching this. If you're a TOS fan, you won't regret it.

Hewitt Drew It! screencast directory update

Paul Hewitt continues to produce screencasts. And I think I've final caught up with him on my simple, home-made directory.

Screencasts for Atomic and Nuclear Physics and Relativity have not yet been released. But there are over 120 Conceptual Physics screencasts out there right now!

Hewitt Drew It! Screencast Directory

Lightning shot at 11,000 FPS

PetaPixel has an article about some incredible high-speed lightning video. And they link to the goods!

Incredible High Speed Video of Lightning Captured at 11,000 Frames Per Second

Here's the clip posted to YouTube.

Incredible Slow Motion Lightning Strike! (1 sec. = 3 min!)

I had never seen the "sparkling" high in the clouds as the stroke develops. So much randomness before a channel is established. The things you can see with high-speed video!


This month's The Physics Teacher (TPT) includes my most recent contribution to Paul Hewitt's "Figuring Physics" panel. Figuring Physics questions are not easy to develop, and many good questions are not good Figuring Physics questions.

Here's a link to the page that will give you access to downloading a PDF of the panel.

January 2014 Figuring Physics

Apparently TPT now waits a month before revealing the answer panel. So you're on your own for now.