Charging Ahead 2020

This year's Van de Graaff portrait gallery. Enjoy.


I'm migrating from Flickr to SmugMug. One apparently owns the other, but they continue to operate as separate entities.

Van de Graaff is the Coiffeur 2019

It was another hair-raising experience when we charged up the Van de Graaff generator this year.

The conditions were often less than ideal. But we charged ahead with our old 1960s-era Cenco Van de Graaff. That old thing can produce a nice charge.

Hair are the results.

2019 Van de Graaff Album

Physics Fun on Localish

Ray Hall is a California physics professor and a skeptic friend from way back. So yes, he is made of win.

He has also crafted arguably the best account on Instagram: physicsfun. And by "arguably" I mean that you and I might have an argument if you think there's a better Instagram account out there.

As a delightful bonus, physicsfun passed the million follower mark months ago: a reason to be hopeful for the future.

If you don't have an account on Instagram, physicsfun is a reason to get one.

Folks are taking note. ABC's Localish produced a nice segment on Ray and his Instagram.

S1E31 Crazy for Physics on Instagram 

Instagram: physicsfun

Want to be ferocious in college? Take physics in high school!

I have been running poster-based ad campaigns to promote physics enrollment since the 1990s. (I tried personalized, direct mail prior to that, but that was troublesome and expensive.)

Previous campaigns were documented in previous blog posts: 2016 and 2012.

But after 30+ years of teaching, some things lose their novelty. Homecoming rallies. Actually, any rally. I could go on, but I digress.

I wanted to use a different campaign for Fall 2019 sign-up season. And that season is coming up soon.

Each of us has our own school community, culture, and instructional styles to work around when designing ads. I did my best to take these into account for this newly-minted campaign.

As with the previous campaigns there is a theme and variations on that theme. Some employ my own photographs. Others use found images, some more classic than others.

These may or may not work for me. Advertising is a fickle alchemy at best. You are certainly welcome to use them if you think they may work for you.

Click to embiggen.

Physics teacher conferees treated to a demo show par excellence

Images from the 2018 Summer Meeting Demo Show, July 31 at the Renaissance Hotel & Conference Center in Washington, DC. Show produced by AAPT's PIRA Team (ft. David Maiullo and Stan Micklavzina) in conjunction with the Bubble Magic of Tom Noddy.

2018 07 AAPTSM18 Demo Show

Rio Phyz 2018 media shoebox

There is no history unless you record it. I used to be much more active in getting candids in class of students conducting lab activities.

But I still like to get some from ExploratoRio. So I get students to snap up what they can during the event. I sifted and sorted, then cobbled together a slide show in the Mac OS Photos application. Set it to a bit of music, then uploaded it to YouTube. Turns out, you have to set the video to "private" when you use copyrighted music. So that's what I do. Here's the link.

Fascinated: The ExploratoRio 2018 Slide Show


I still break out the camera for Egg Toss and Van de Graaff generator activities. And class portraits on the day of the final exam, immediately following the issuance of the class's PhyzMaster certificates.

Here's the photo album.

Rio Phyz 2018 Photo Album

Fluorescent Puffin Bills and Tetrachromacy

Serendipity. What a great thing among the scientifically curious.

Ornithologist Jamie Dunning’s serendipity compelled him to shine ultraviolet light on the already decorative bill of a puffin. And he saw something apparently not previously documented in the learned journals.

Birds, those opulent tetrachromats, are apparently up to their colorful shenanigans once again. We humans, humble trichromats that we are, just miss things sometimes. (It’s clearly not just the ability to fly that makes Naomi Hamilton Jealous of the Birds! But I digress.)

Read the story, behold the images, and mention it when you teach about colors and color mixing.

Puffin beaks are fluorescent and we had no idea.

A place for everything

Physics teachers hope to inherit or acquire useful lab apparatus. When I arrived at Rio Americano in 1986, the physics program had suffered through a year of long-term subs and mis-assigned teachers. Prior to that, the physics teacher was someone who was handy with tools and a fan of PSSC. We didn't have much, and what we had was dedicated kits aligned to the PSSC lab manual, conceived and produced in the post-Sputnik, pre-Apollo era.

I have had the good fortune of securing funds for considerable capital outlays for quality physics demonstration and laboratory equipment over the years. Rio's School Improvement, Gifted And Talented Education, Parent Teacher Association, and Science Boosters programs have funded a variety of my requests. It's been a patient siege, but in due time, the classroom was well-stocked for my needs.

When I did my student teaching at Ann Arbor Huron High, there was a physics equipment storage room the size of a regular classroom with rows of shelves: it was essentially an apparatus library. When I was a student in a physics class at Grand Rapids Central High, there was a classroom and a lab room. At Rio I have my classroom and share a tiny storage room with a neighbor. So what I get has to fit in a small, fixed amount of space.

Here are a couple of storage solutions I've adopted and continue to appreciate. Now that I teach four different physics courses, I often need to haul out or store materials in the wee breaks between classes. Half-gallon milk cartons, small utility tubs, and removable drawer storage are leveraged throughout the classroom.

The analog current and voltmeters stack nicely into the tubs and the tubs fit nicely into the drawers.

Brass masses and mass hangers store nicely into strategically cut milk carts, and the milk cartons fit into the tubs. As do sets of disparate clamps.



Flip a couple of the milk cartons for convenient tub stacking. There is no tubthumping.



When the classroom was "modernized" in 2000, two storage cabinets were added. And promptly filled.





I'm an unapologetic fan of removable drawer storage racks of all sizes.

Here are photos of lab sets of correlated items:

Dynamics carts



After students have used the materials and it's time for clean-up, it helps to have a photograph of how the drawer should look when restored to its low-entropy status. Lay it on top when storing the drawer. I printed this latest edition (with the new Smart Carts) on heavy card stock.



Circuits (batteries, bulbs, wires, switches, power resistors, capacitors, magnetic battery connectors)



Magnetism (bar magnets, compasses, wires, lead-free solder, ignitor battery, rod clamp, collar hooks, wood dowel, Ampere's Law apparatus, Genecon)



Wave Optics (CD, whiteboard markers, binder clamps, diffraction gratings, laser tripod)



Clickers (each group is assigned four: e.g., Group E: E1, E2, E3, E4)



The plastic removable drawers are also nice for storing class sets of a particular item, like force sensors.



On the off chance that I've left you with the sense that I'm a fastidious neat-nick, I assure you that the rest of my classroom (and much of my humble abode) are ongoing celebrations of disorder.

Left Behind: Sunball Selfies

Many science instructors will be making the pilgrimage to totality for the August 21 solar eclipse. This will leave science students without their instructors during the event.

In a previous post, we offered a lesson plan to fill one day of a science teacher's absence. That was a question set to accompany showing The Universe: Total Eclipse.

What can students do on Monday, August 21 at the time of the eclipse (peaking at 10:17am in Sacramento)? It's a school day and students will likely be in class during most of the eclipse.

Perhaps your school has stocked up on eclipse viewers/glasses and will distribute them for students Monday morning. Then again, maybe not. It's important to convey the danger of looking at the sun during an eclipse.

Conceptual Physics author, Paul Hewitt, reminds us that one of the best ways to enjoy an eclipse is to look down! The dappled light seen beneath trees is composed of pinhole images of the sun: "sunballs". When the eclipse is on, these sunballs turn into "suncrescents," pinhole images of the eclipsed sun. It is quite a spectacle. Some might even call it "amazeballs".

Here's an extra credit project that I will be assigning to my students for the eclipse:

Sunball Selfies (pdf) - Sunball Selfies (docx)

You will need to modify the document to use it at your school. And you don't need to be absent to use it. I used a similar assignment for the May, 2012 annular eclipse and students had great fun with it.

Sunball Selfies student album from May, 2012


My own Sunball Selfies album from May, 2012

BAPOD: Bad Astronomy Photo of the Day

I feel like astronomy photos have a much higher possibility of being "fake" than do those of any other discipline. This is not to be confused with artistic representations of celestial objects we don't have actual pictures of. Often these artist's drawings are believed to be real, even if labeled, leading to more confusion. I will never forget showing students an artist's rendering of the Milky Way and pointing to one arm of its spiral saying, "And the Earth would be approximately here," when one student pipes up in utter disbelief, "Wow, who went that far to get that picture?"

Ummm... nobody. That was also the year I had a debate with a student that insisted The Martian was based on real events.

So astronomers, astrophysicists, planetary scientists, etc. has a tough time educating the public about their science as they combat some really bad misconceptions. [I won't even address the flat-earthers.] Their struggle is not helped when images like this go viral. Take a minute to look at it and think about everything you know about the sun and the moon.

Had a minute? If it doesn't come to you right away I have a few questions to help:

1. How are we able to see the sun?
I teach my students that some objects are luminous, meaning they give off their own light. Stars like our own sun are one of those things. We see it because it emits (or makes) its own light.

2. How are we able to see the moon?
Is it luminous like our sun? Some students would say yes but check the definition again. Does it make its own light? Well, no, nothing in our Solar System is luminous except for our sun ... so how are we able to see it if it doesn't make its own light? Right about now I would hear some students hesitantly saying, "Is it ... reflecting the sun's light?" Gold star for you! We see the moon (and all other non-star objects by the way) because they reflect light from the nearest star. The moon is illuminated by the luminous sun and it is that reflected light that we see.

3. So if we can see the illuminated moon, where should the sun be?

Hopefully you're at the forehead smacking moment. In order for the very full moon to be photographed it must be reflecting back the sun's light to the camera. The side of the moon that is facing the sun is always lit, and that half that is lit is not always facing the Earth. If you can see a full moon you have to be facing away from the sun and towards the side of the moon that is facing the sun, reflecting its light and thus able to be seen. It is not physically possible to catch a full moon and the sun in this shot as is above.

There are many other astronomers and amateur enthusiasts that can probably explain it better than I. In fact the Reddit, Twitter, Imgur and Facebook takedowns are pretty amusing if you're interested. The picture is apparently not new, the oldest post I could find was from 2014 on Google+ of all things. But I would like to make the point that some pretty basic understanding of the arrangement of our sun-moon-earth system let's you spot an (amazing but) obvious fake.

With the approaching total solar eclipse in North America, I suspect there will be a lot more of "Incredible photos you won't believe!" Because you probably can't, for good reason. My favorite example of making it obvious what the proper eclipse arrangements are comes from astrophysicist Dr. Katie Mack:

🌓🌎🌞 <-- lunar eclipse

🌎🌓🌞 <-- solar eclipse

🌎🌞🌗 <-- apocalypse

— Katie Mack (@AstroKatie) October 5, 2014

So next time a family or friend shares an "amazing astronomy" photo, take a close look, think critically and be prepared to (politely) rain on their parade.

Dean adds: Having the invoked the namesake of Phil Plait's Bad Astronomy, we would be remiss not to throw him a link! An unreal picture of sunset at the north pole

March for Science: Dean's Day in DC

[Click any image to embiggen.] The forecast for the day called for rain, and left little room for doubt. I packed a rain jacket and rain pants (in the event of sideways-driven torrents). I packed an umbrella in case the rain remained vertical. I also covered exposed skin with sunscreen and packed a floppy hat in case the forecast was defied by reality. I wore heavy-weather shoes and thick wool socks. I packed a fleece as the forecast high was in the upper 50s. I knew I was going to be in the elements for the day. I wasn't go to bail no matter what. And I didn't want to be too uncomfortable.

But in the morning, the weather was still fairly mellow, so I was able to expose my custom T-shirt.

I walked the mile and a half from my hotel to Pershing Park, where I was told representatives of the AAPT would be found. DC bustles on weekdays, but can be a ghost town early on a Saturday morning. I grabbed some breakfast at a bakery/cafe that was doing a brisk business with science marchers.

I found some familiar faces (Dan Brown and Rebecca Vierra) at Pershing Park; AAPT Director, Beth Cunningham quickly joined, as did some Society of Physics Students (SPS) enthusiasts. A retired chemistry instructor showed up in his rainbow tie-dyed lab coat, so I hauled mine out of my pack and matched his look. We socialized and snapped pics for a while before making our way to the rally at the Washington Monument.

We knew we were headed in the right direction as we followed these two brainiacs.


We settled in some distance from the main stage, but with a nice view of a massive screen (atop a truck).

At 10 o'clock, the program began. Veritasium's Derek Muller, Cara Santa Maria, and The Roots' Questlove acted as masters of ceremony. A precipitous mist turned into sprinkles as the program continued. The rainbow lab coat was stowed, and my rain jacket was deployed.

Speakers, music performances, and short films ensued. The rain picked up. It continued in waves. When it got heavy enough, my maize & blue Michigan umbrella was raised. Umbrellas were ubiquitous throughout the crowd. But you feel bad when packed this tight while using one. It blocks views and sheds water on your neighbors.

Four hours of rallying would have to pass before the march was to proceed. Scientists were celebrated, a call and response of "I say 'public' you say 'health'" was launched.

The rain never really stopped. When the wind reached a certain persistence, I undertook a pit-crew donning of my fleece between my t-shirt and the rain jacket. Had it not been such a tight pack where I was, I would have tried to put on my rain pants over the quick-drying trail pants I was wearing.

Near the end, we got a call to action from Bill Nye, himself.



And an Earth Day tweet from... not Donald J. Trump, but from Pope Francis.


Then it was off to the march. We slowly cattle-herded our way out of the secured Washington Monument grounds to Constitution Avenue and marched to the US Capitol.

From time to time, an enthusiastic roar would make its way through the marchers. And there were chants.

"Show me what a scientist looks like : THIS IS WHAT A SCIENTIST LOOKS LIKE!"

"Science--not hate--makes America great!"



The sprit was great and the energy was positive. The signs were very clever and were all spelled correctly. Hbar vs. FUBAR, Show us your taxa!"

I stopped for a requisite US Capitol selfie.

At march's end, marchers laid down their signs along the walkway and fence leading to the Capitol: the impromptu sign graveyard blossomed and grew as more and more marchers finish the route. The rain had taken a toll on most of the signs, and the wind added entropy to the otherwise carefully placed placards.



Snake Oil Trump will haunt my dreams for nights to come.


At the end of the day, there was no way to navigate around the reality that science is under attack in the US from the Republicans who hold the presidency and majorities in the Senate and House of Representatives. It is likely that they will do significant damage to science and the environment as rapidly as they can. It is unlikely that they will change. We cannot nourish a hope that the attack will relent while the GOP maintains unbridled governmental power.

If scientist hope to get work done in the lab, they will need to get work done at the ballot box first.

I'm glad I was able to be in DC for the March on Science. I have more photos in my Flickr album and more videos on my YouTube channel.

March for Science Photos:

Is there gas in that light bulb?

I'm a fan of topics in thermal physics. Not thermodynamics as much as temperature, heat, and heat transfer. These topics have been largely abandoned by NGSS (HS-PS) and are not included in AP Physics 1. For the moment, I teach AP Physics 2, which has some concern for thermodynamics. That gives me reason enough to teach thermal physics as a precursor.

We cover that content in the fall. We are now into geometric optics. That's how it was that I came to have a 40-W incandescent bulb with a dimmer switch on a gooseneck lamp glowing on a classroom table. I was demonstrating the classic image-formation trope of "What will happen the to the image if half the lens is covered?" (It's right up there with "How would the results of this [mechanics] experiment be different if it were conducted on the moon?" among well-worn item-writing chestnuts.)

But we had a few minutes before the end of the period. So I offered a question: "How could you know whether or not there's gas in this bulb?" If I had planned this inquiry a bit better, I would have  begun with "Why is the filament enclosed in a glass bulb?" If incandescents weren't becoming increasingly rare, we could break the glass on one and see what happens when the filament is exposed to air.

Of course, the immediate solution posed by my thoughtful teenage (mostly male) scholars—after milliseconds of contemplative deliberation—was "break it!". You hardly need a question. The best and most immediate answer is going to be "break it!". It just is.

I asked how breaking the bulb would reveal the answer to the question. Forced into a corner of their own making, they suggested weighing the bulb before and after the break. A difference in weight would reveal the prior existence of the gas. I argued the difficulty of the logistics and the precision required.

To move them off the property destruction solution, I moved the goalposts. How could you know without breaking the bulb? And without any other instruments? Hemming and hawing ensued. The end of the period was approaching.

Is the glass strong enough to hold up under atmospheric pressure if it's evacuated? Maybe. Could there be a gas in there given the rapid burn-out that happens when the filament is exposed to air? Yes: inert gases, noble gases.

I touched the bottom of the bulb and reported that it was warm. I casually kept my fingers on the glass of the bulb. Didn't the transfer of heat from filament to bulb require a conducting medium? No, they insisted. The bulb could have been warmed by thermal radiation.

An inquisitive student got up and touched the top of the bulb. He did not keep his fingers on the bulb very long at all and complained about how hot is was. (I had adjusted the 40-watt bulb down to about 10 watts, so it wasn't as bad as it could have been. I also assured him any burns would heal in a few days.)

At that point, they got it. The bottom was warm but the top was hot. Gas in the bulb is heated by the filament, rises, and deposits heat on the top of the bulb. Convection!

The key to knowing there was gas in there was feeling the top and bottom of the bulb. Having the bulb in a horizontal orientation helps: you have a "top" and "bottom" made of the same glass. The FLIR One thermal camera image was an afterthought, and is not needed to develop a solution.

When the period was over and students were filing out of class, the inquisitive student told me that breaking the bulb could be a simple solution, as long as you broke the bulb underwater.

He had me there.

Olympics in motion pictures

I want to share all of these with my classes during kinematics! The NY Times posted these great Olympic moments in composite pictures. Often simple motion is modeled for students by showing the object in successive photos in the same image. By comparing the distances between the object over time students can get a sense of how quickly it is moving.

When viewing the page you will scroll down but will actually be moved to the right in order to see their full width. Some of the images like the one above seems to be taken in even intervals of time and would therefore be easier to compare. So how can you use them? Let's take a look:

Christian Taylor's gold winning triple jump:

Notice that Taylor's body makes a parabola while he's in mid air for the long jump. What might be surprising is that there is also a clear parabola in his bounds before his big jump. You can trace over the image along his center of mass and show students the parabola shape. You can also point out Taylor's change in position at the end during his jump and discuss his center of mass.

"On match point in their semifinal, the Brazilian team of Barbara Seixas and Agatha Bednarczuk ousted Kerri Walsh-Jennings and April Ross of the United States."

There are great parabolas to be seen in the projectile motion of this volleyball. The volleyballs are closer together at the top of the parabola because it is moving slower and will not travel as far in between each picture. 

Derek Drouin's winning high jump:

This image shows Drouin's change in speed as the distance between each changes. There is a great parabola during his high jump and you can see him change the position of his center of mass. 

Laurie Hernandez on the balance beam:

I would use this to show students that even when it seems like she's floating on air her center of mass is always supported by a base underneath her. In the first few images show her feet underneath her. The fourth shows Hernandez supported briefly by her hands. As she dismounts you can see a parabolic shape if you follow her center of mass through her flip. 

Anytime you can relate what you're studying to the "real world" for your students is a win.

Independence Day 2016 fireworks at Cal Expo

It's tough to have serious camera gear and sit out a big fireworks show. So I tend not to.

Photographers more serious than me (and that's nearly all of them) focus(!) on shooting(!) fireworks with a photographically interesting foreground. Maybe someday. I'm so simpleminded as to be enthralled with the fiery blossoms, themselves. And trying to get a few keepers after each show.

My recommendations (to myself, if no one else) after this year's experience:

• Lens: 15mm (or 24mm—70mm set to 24mm)
• Tripod is required to stabilize the camera; a bullhead or tilt/pan is need for aiming
• Cable release is required to control the shutter without wiggling the camera
• ISO: I will set mine to "L–1.0", the lowest ISO I can get my camera (Nikon D800E) to go to—it's faux ISO 50
• Mode: Manual
• Aperture: f/11 (at f/8 this year, I was still getting blowouts—admittedly, I was only at ISO L–0.7)

Note: The D800E's dynamic range when capturing RAW images is great enough that one can bring up underexposure in post. But once a pixel is blown out (overexposed), there's no bringing it back. A bit of underexposure is acceptable. Too much will require bringing everything up, including the relatively dark yet somewhat illuminated smoke, and nobody wants that.

• Shutter is set to "bulb"—pushing the cable release opens the shutter; letting it go closes the shutter
• Metering is irrelevant here; the camera isn't making any decisions about exposure
• Focus: Manual—I focused at a distant light pre-show and confirmed
• Image quality: RAW (no in-camera processing)
• Long-exposure noise-reduction: Off (to prevent any in-camera processing)
• Live view: Off

Having the correct settings is a start. Next, you have to aim decently enough to contain the glowing bursts. The real trick is knowing when to open and close the shutter. Open too late and you get "porcupines" (streaming trails that seem to come from inside a black sphere). Keep it open too long and the frame gets too busy. Blowouts ensue.

Post-processing is where you can bring up the exposure if needed. Beyond that, I can go completely crazy with saturation and other settings. By eschewing "interesting foreground," I am free of any post-processing inhibitions.

With all that in mind, here are the keepers I got this year.

Dank memes

It's impossible to participate in social media without being inundated with images emblazoned with captions that overlie the images. These are not factually captioned photographs. These are humorously graffitied screen-captures or illustrations commonly referred to now as Internet memes ("meems"). The term, meme, refers to something else.

They are a sort of lexicon in Twitter, Facebook, and the like. A cultural fad, or here to stay? Who knows. In the meantime, I dipped a toe in.

I was first compelled to create a few in support of my "Equation, Rearrange, Substitute, Answer" recipe for students to use when solving problems. But the craft is limited only by one's creativity and comedic skills.

After posting a few in class, students wanted to join in. But they don't always have the same sense of decorum and propriety that sets boundaries on what a classroom teacher might feel comfortable posting.

One student aficionado referred to top-quality caption/images as dank memes ("may-mays"). I thought he was making it up until I found an online urban dictionary pronunciation. Dank meme can also be a sarcastic term for old / overly done memes.

When creating memes, the reflexive urge s to create "nag memes".

Encouragement meme are harder to produce. The encouragement element cuts against the sarcasm/humor element. One does one's best.

But wait. Why not make some with a physics theme?

I think it's important to "save a blade for yourself". It's no good to criticize the world with nag memes while holding yourself above the crowd. Easy? Yes. Comforting? I suppose. Good? No.

It's important to remember in all cases where social media and teachers intersect. I'll illustrate with news item headlines:

Teacher awarded prize for poignant Facebook post

Teacher fired following controversial tweet

One of these headlines is plausible. The other will never appear above a real news item. For teachers, there are two outcomes possible when participating in social media: nothing or negative. There are no positive outcomes. Only negative. Or—at best—none.

I generally trust colleagues to their best judgment to avoid creating memes that border on racism, sexism, etc. But at the last YouTube Physics session I hosted, a colleague traveled to The University of Minnesota AAPT SM14 and come to the session just to share this gem, which he thought was a great thing to show students in a physics class. So… yeah. If AAPT ever does a YouTube Physics session, it would probably be best not to use the "open mic" format.

So remember,

And be careful. You'll do better connecting the message to students if you know what the common use of a particular meme is. Once you know what the standard use is, you can bend it to your own use.

Here is a Dropbox link to the memes I've created: Memes

And I would be remiss if I didn't provide a link to Buzzfeed's 61 Best Teacher Memes.