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Exploring the Hydrogen Spectrum with Glowscript

November 13, 2018

As part of my sabbatical work at the Center for Computing in Science Education, I’ve learned a lot about the Norwegian Science and Math Curriculum, and gotten to meet some teachers who are doing very great work at bringing programming and computational thinking into their classes. In the next few posts, I want to share out some examples of what I’ve been working on.

One topic that isn’t a part of the high school physics curriculum I’ve taught is the Bohr model and in particular, the formula for calculating spectral lines

\frac{1}{\lambda}=RZ^2\left(\frac{1}{n^{'2}}-\frac{1}{n^2}\right)

I must admit I’ve always found this formula a bit hard to build an intuition around. You’re calculating the inverse of a wavelength, and it’s dependent on the difference of the inverse of the squares of two integers. It was easy enough for me to realize that if you transition over a greater number of quantum states, the energy of the released photon must increase, resulting in a higher frequency, smaller wavelength photon, but that was never obvious to me from working with this equation as a student.

A teacher I met designed an activity to give students more practice with thinking about this formula by asking them to write a simple python program to calculate the wavelength of the emitted photon for a given transition. Once they had this program, it was much easier for students to think conceptually about questions designed to push their understanding. For instance, you could ask them to calculate the wavelength of the transition from n = 101 to n=1 to the transition from n =100 to n=1 and let them see that these wavelengths are nearly identical, and then come to the idea of ionization energy.

This discussion got me thinking that a glowscript program might add a bit more to this work since you could also display the spectral line that is produced for a particular transition. After doing some searching for some code to convert wavelengths to RGB values, I was able to put together this program:

Bohr Spectrum

And here is what the program produces. The top black bar is the reference spectrum of the Balmer series. If I were giving this to students, I would remove the lines 14 and 15 that calculate the wavelength of a particular transition, and ask students to implement the function to calculate lambda. Then I would ask them to try various transitions to see if they could produce the Balmer spectrum.

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I’m not sure this is the deepest application of computational thinking—basically, students are just writing a few lines of code to do a calculation they could easily do on a calculator. But I do think it provides students with a tool to explore spectral lines a bit more and start to develop some insights about the relationship between transition energy and wavelength, and with the right prompts, insight into what sorts of transitions will produce visible spectral line, which might give a bit more meaning to the sea of names for spectra we have—did you know that we have names for 6 different series? Lyman, Balmer, Paschen, Brackett, Pfund, and Humprheys? Honestly, before I started working on this program, I had no idea why there were even separate names for these series, but I now see that they’re named according to the final energy level of the transition.

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Sabbatical goal—visiting 25 classrooms both real and virtually

August 15, 2018

I’m now mostly settled into life in Norway and despite a few challenges, really loving Scandinavian life (read all about it in our sabbatical blog, A Year in Norway).

I’m going to starting work at the University of Oslo in a week, and I’ve begun to think of goals for this year. One goal I have is to visit a lot of classrooms and talk with many physics teachers. Unfortunately my Norwegian hasn’t made a ton of progress, thus I’m going to need to reach a bit farther afield to find some teachers to connect with.

My goal is to visit 25 classes/teachers this year. A long time ago, I wrote about virtual coaching, and a few intrepid folks signed up, and we ran some great sessions—I think I saw a couple of physics classes and even a Spanish class, and had some stimulating conversations with the teachers of those classes.

This year, I’d like to bring this project back, and I’m hoping that you might be willing to invite me into your classroom. Since I’m on sabbatical, and my work at the university is likely to be rather flexible, I’ve got a good bit of time on my hands. Here’s a rough idea of what I’m thinking:

  • We set up a pre-visit chat where we discuss your class and you let me know what you’d like me to observe.
  • I visit your class virtually, which would likely involve you setting up a laptop or tablet with skype or zoom and livestreaming your class to me.
  • We set up a debrief to talk about what I saw.

If you’ve got a different idea in mind, I’m open to modifications to this structure. If you’re interested in seeing if this could work, then please fill out this interest form.

A tale of two museums

August 1, 2018

(Note: I’m cross-posting this post from my sabbatical blog, A Year in Norway, since I think some of my regular physics teacher readers might find it of interest).

During our week in Paris, we had the chance to check out two science-related museums, the Musée Curie, and the Cité des Sciences et de Industrie.

I decided to write up this visit in the form of a letter to the curators of the Cité des Sciences et de Industrie that I will be mailing soon. Read on, and you will understand why.

Dear Curators,

Last week, I had the pleasure of visiting your museum with my wife and two daughters. My eldest Daughter, Maddie (age 7), has developed a passion for all things science, and physics in particular, so our first stop was the exhibit on the Great Story of Our Universe. As a high school physics teacher, I was eager to explore this exhibit with my daughter.

At first, I was struck by just how beautiful the exhibit was—your designers did a marvelous job of creating a inviting space that wonderfully used lighting and texture to evoke a flow through the origin of our universe, with great hands-on experiments that allowed you to touch and view meteorite samples, or see a live infrared photo of oneself to understand how we are able to classify stars based on the light they emit.

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Maddie looking at some meteorite samples.

I was particularly impressed by so many of the simple but engaging experiments—a parallax experiment that explained how we measure the distance to stars, by demoing how to make a measurement of a “star” on the wall across the room. My favorite demo of all was the side by side model solar system and galaxy, and the text that invited the patient to see how these two models behave very differently. Maddie and I watched it for at least 5 minutes, and she made so many observations about the differences she saw. What a wonderful introduction to Dark Matter.

After getting through the first floor of the exhibit, I was pleasantly surprised to see it went to a second floor that explains the strange physical laws that “enable us to describe and understand the evolution of the Universe.” Here again, I was impressed with all the interactive exhibits and even more impressed with your efforts to explain not just some of the oldest physical laws like gravity and electromagnetism, but also to fully cover discoveries in quantum mechanics (we loved Schrodinger’s Cat in a Box), and even some very recent discoveries in cosmology.

As I walked around this exhibit, I began to notice something strange—every column in the exhibit featured the name and biography of a famous physicist or mathematician, and every single one of them was a male. I’m also pretty sure that they were all white European men—Newton, Galileo, Descartes, Schrödinger, Lorentz, and on and on—more than 20 names in total. I looked hard, and I didn’t see a single woman or person of color in the entire collection.

In another part of the exhibit on the second floor, there was an exhibit presenting nine quotes about the nature of the universe from scientists and philosophers throughout history, and every one of them came from a white man, as best as I can recall.

It’s easy to come away from this exhibit thinking that our entire understanding of the universe, and the field of physics, is the result of the work of a bunch of dead white dudes with gray hair and more often than not, a mustache, leaving out so many important stories of women who have contributed to this understanding and what the field of physics looks like today.

There are so many incredible women scientists who have made deep and profound contributions to this story, that I find it hard to understand how they could all be left out of this exhibit. Adding a description of Vera Rubin and her groundbreaking work on galactic rotation curves would have have been an informative and powerful addition to the first-floor exhibit about the rotation speeds of galaxies and our solar system. Marie Lavoisier, Marie Curie, Joycelin Bell, Henrietta Leavitt—each of these women made major contributions to experiments and discoveries that were already mentioned or alluded to in your second-floor exhibit, and they have inspiring and important stories that are worth sharing with visitors to the exhibit.

With the exhibit’s vast amount of space and focus on highlighting recent discoveries in physics, I can imagine a wonderful addition that highlights very recent discoveries in physics—like the discovery of gravitational waves, showing photos of the hundred-person plus team that made this discovery. A wall featuring photos and descriptions of scientists today could very well inspire many of your youngest visitors to see themselves as scientists and imagine how they might contribute to understanding the universe when they grow up.

This exhibit also raises the opportunity to talk about why the field of physics has been historically dominated by men—specifically pointing out the ways in which women have been excluded from educational opportunities and research organizations since practically the beginning of science. At the same time, you could point out the hidden and unrecognized ways in which women have made vast contributions to the field of physics—from serving as the “human computers” to painstakingly type the dissertations of their husbands. Perhaps this conversation looking at the nature of who does physics could be a web resource, similar the great ones I saw on the ground floor in Cite des Enfants, where the signage encourages parents to visit a website for more ideas about how to engage children in the experiences they had in the museum.

I know that museums are incredibly powerful places—they are some of the most important places for inspiring young people and opening their minds to possible careers and ideas they would not have otherwise considered. This was made most clear to me in the case of my own daughter, who developed a love for Marie Curie after reading a short story describing her life in “Goodnight Stories for Rebel Girls.” After reading that story, Maddie decided she wanted to be a scientist just like Marie Curie and wanted to know all she could about the Nobel Prize. When Maddie read in the story that Marie Curie lived in Paris, she asked us if we could visit her house, and through that, we discovered the wonderful Museé Curie, a tiny three-room museum dedicated to the life of Marie and Pierre Curie. Maddie pushed this museum to the top of our Paris agenda, and watching my daughter in this space was magical. Maddie was thrilled to see Marie Curie’s office just as it existed, but she spent the most amount of time scrolling through images of Dr. Curie and her family on a large video screen, occasionally fixating on a picture of Marie Curie on her wedding day. Maddie has been super fascinated with weddings recently too, and when we talked about it leaving the museum, she told me how awesome it was that her hero, Marie Curie, was also able to get married. To me, this visit scored the trifecta of science museums—it helped my daughter to not only understand an important discovery in science, it helped her to relate to the story of the human that made that discovery—emphasizing her humanity and helping my daughter to see that she too can be a scientist.

IMG 0644

Maddie in Marie Curie’s office.

I wish we had more time to explore your museum. I’m sure I missed many exhibits that did celebrate the work done by women in science, and help students of all backgrounds seem themselves as scientists. I appreciate your consideration of these suggestions and look forward to visiting the museum again in the not too distant future.

Sincerely,

John Burk

Physics Teacher and Dad of wonderfully curious 7-year-old girl who wants to be a physicist

Opening the school year with a letter to your physics teacher

July 15, 2018

Every year, I seem to go through some variant of an introduce yourself to your teacher activity, from asking students to fill out some sort of template I’ve created or to answer a Google survey. All of them have been fine—I often find myself learning some useful things from every response, and in the best cases, they do set up a basis for a building a strong relationship between me and the student.

This past year, I wanted to do something a bit different. I expressly wanted to start a dialogue with students, and I wanted to open up the format so that they could share with me the things that were important to them, rather than filling in answers to the questions I had. I also got the idea that we don’t really write letters anymore, and in the past, some students have gone the entire year without ever emailing their teacher.

So to change things, I invited students to spend 30 minutes writing me an introductory letter to me. I gave them some of the questions I’d asked in previous questionnaires (mostly cribbed from Moses Rifkin). Here’s the assignment (also as a Google doc):

Introduce yourself

I’d like for you to introduce yourself to your teachers by writing a letter. The purpose of this letter is to help your teacher to get to know you better as a student, especially when it comes to knowing how I can help you to see success in physics and achieving your personal goals. We ask that you write this letter by writing continuously for 30 minutes—don’t stop to think about what you should say, and don’t spend time proofreading or trying to find the perfect word. You will find that writing continuously is often the key to discovery—of a solution to a problem, of a thesis for a paper, or in this case, insights into who you are and why you are taking physics.

Here are some questions you can consider answering in your letter (don’t feel obligated to answer all or even any of these).

  • What should I know about your prior experience with science?
  • Is there anything you’re thinking after today’s class that you’d like to share?
  • What motivates you?
  • What are your goals for this semester?
  • What can I do, as your teacher, to help you learn best?
  • If you are struggling in this class, what can I do to help you?
  • If you are struggling in this class, what will you do to help yourself?
  • What languages do you speak at home?
  • What do you like most about yourself?
  • Tell me about something you’re good at UNRELATED to science.
  • What do you think of when you hear the word science?
  • How do you think physics might be useful for your future goals?
  • What’s the last idea that fascinated you?
  • Who is your favorite teacher and why?

Why a letter?

It turns out that writing a letter is often the key unlocking incredible opportunities in your life. It might be an interview, internship or just a cup of coffee, but the simple act of writing a letter to someone can change your life. Sadly, we don’t write many letters anymore, and sometimes, students don’t even know how. So consider this practice for the letter you will write sometime in the future that will change your life.

The responses to this assignment turned out to be incredible. Students wrote thoughtful letters that gave me real insights into their personality, motivation, interests and more. In general, I would say students had the hardest time responding to the “if you are struggling” questions, and I often didn’t get much more than “you should be available for extra help” and “I should work harder and come to you for help.” Both of these responses are a good start, but make me thing there’s a way I could ask this question to get students to be a bit more specific and also to see all the possibilities for help that exist beyond just setting up a meeting with your teacher (which many students seem to see as a very drastic step they are reluctant to take). To that end, I really like this much more specific survey Brian Frank (@brianwfrank) shared on Twitter earlier in the year.

In trying to build a conversation, I responded to each letter at length, asking follow up questions, trying to answer their questions and foreshadow what’s ahead. Though I had no expectations busy students with lots of homework to complete would follow up or even read my feedback on this non-graded assignment, a number did reply, leading to some great conversations and deepening connections.

If I were to do this again, I think I would add one thing—I would require all of my students to set up a 5 or 10 minute meeting with me after I’ve responded to their letter. This is something I definitely couldn’t do if I had a 100 student course load, but even with the small teaching loads, I’m lucky to have, some students still go all year without ever meeting with me outside of class. I think setting this requirement would go a long way toward building trust and giving students the comfort of having already met with me if they find they need to seek out extra help in the future.

I’m on sabbatical

July 1, 2018

For the 2018-19 school year, I’m going to be on sabbatical. I’ll be living in Oslo, Norway with my family, and working with some amazing researchers at the University of Oslo to add computational modeling to the Norwegian Physics Curriculum. Hopefully, this sabbatical will allow me to get back in the habit of blogging—there are a ton of things I would like to share, especially some physics related projects that I plan to work on this year.

But in the meantime, you might be interested in following our family blog about our adventures in Norway: A year in Norway.

Help me find a new home for a cache of old PASCO datalogging equipment

February 27, 2018

Note: Thanks to some wonderful responses to this post, all of this equipment has now been re-homed.

As part of the preparation for a renovation of our building, we are inventorying and packing all of the physics equipment at my school. One thing we are trying to also do is purge a bunch of the equipment we no longer use, and as much as possible, avoid sending discarding this stuff to fill a landfill somewhere. We’ve acquired a bunch of unusual equipment over the years, including a giant slide rule and giant micrometer, and thanks to the wonderful people of Twitter, I was able to find homes for both of these items.

Now I have a small cache of PASCO Datalogging equipment—750 Interfaces and a bunch of probeware. I also have a bunch of old PASCO dynamics carts, all of which I would like to donate or sell. A word of warning about the PASCO equipment—this equipment does not work with the newer wireless sensors, or even the SPARKVue sensors, as I rudely discovered when I tried to setup a old style force probe with one of the new wireless smart carts. Though I haven’t tested every single item, I believe all of this equipment is in good working order.

I think the ideal use of these would be a university or school that is already deeply invested in PASCO equipment, and really comfortable with the PASCO capstone software, which can be difficult to use. If you are new to using probeware, and just want to outfit your lab, I’d strongly encourage you to consider going with Vernier and avoiding the headaches of working with this equipment—you’ll be much happier with that equipment—I know we are.

Finally, with the exception of the carts, I’d love to sell/donate this equipment as a lot, ideally to a school with a real need, or if that can’t be found, a school that is willing to pay a reasonable price for it.

Here’s the list of equipment we have available.

If you’re interested in this, please complete this form: PASCO Equipment Interest Form.

Building a Dashboard in Google Sites

December 22, 2017

One of the the things I did at the beginning of this year that has saved me a ton of time is build a simple static webpage in Google Sites with links to all of the things I most frequently use—the specific page for my class in canvas, the page in our SIS that lets me write quick special comments, our electronic grade book and more. Here’s what my page looks like:

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Here are a few quick suggestions of things I’ve found super useful to include:

  • A simple Google spreadsheet listing all of the students in my class and their emails. This is something I started doing a couple of years ago, and it’s turned out to be insanely useful for times when I need to quickly sort my students, keep track of who’s turned in some one off assignment or anytime I quickly need to generate a class list to paste into something.
  • A custom Random Team Generator for each class: We all know the power of visible random grouping, but too often, I find myself pasting in a class last at the last minute to create groups. The awesome Random Team Generator allows me to paste in a list ahead of time, and then gives me a url that I can put in my links page and revisit any time I need to generate new groups.
  • Direct links to your class in your SIS and LMS: It usually takes me 3 or 4 clicks to get to my course page in canvas. I can save myself a decent amount of time just by copying the course link from the LMS and including it here on my links page.
  • A mailto link for my class, or direct link to the new announcement page in my LMS: I haven’t implemented this yet, but having one click access from my default page to be able to send a message to my whole class seems like a big timesaver.
  • A link to my electronic gradebook: It seems silly, but having a direct link to the gradebook page for each class has made it much easier for me to stay on top of grade entry.
  • Links to course materials in Google Drive: It’s truly wonderful not to have to click through folder after folder to get to that assessment or packet I’d like to see.

Google sites is super easy to use and even if you’ve never made a webpage, you’ll probably be able to create a basic quick links page in under 5 minutes with their excellent documentation.

I’ve also started using Practice Logs this year, an idea I adapted from Casey Rutherford and intend to blog about in the near future. One of the best things this page has allowed me to do is put a direct link to each student’s practice log on my links page, so now I’m a single click away from any student’s practice log, which makes it much easier for me to give regular feedback to my students and check to see how their practice is going.

If you do setup a links page like this, you’ll want to make it your default page, and somehow in 2017, my browser of choice, Google Chrome, doesn’t seem to let you change the window that new tabs open to, so I had to use the extension New Tab Redirect, which does the trick.