Just Enough Physics Video Series

I think I need help. I’m not sure of the best way to proceed (or even to do it at all) with this new video project. Here is my idea:

  • Just Enough Physics – the video. Yes, a long time ago I put most of my physics explanations into a self-pub ebook on Amazon. I think it turned out OK. The book is in the KindleUnlimited program, so you might be able to get it for free – https://www.amazon.com/Just-Enough-Physics-Rhett-Allain-ebook/dp/B0052UKTDQ/ref=sr_1_1?keywords=just+enough+physics&qid=1578932997&sr=8-1
  • I’ve made a bunch of physics videos—but they aren’t well organized and they jump over to many different topics. I wanted to start over and make one series of videos that sort of go through the full intro (algebra-based) physics course.
  • In most of my previous physics videos, I used a white board with me in front of it. I think this works well, but I wanted to be able to make videos from home. With that, I decided to switch to a paper and pen method (with the camera just looking at the paper).
  • Also, I figured I would add a Patreon page. It would be nice to be able to work on this over the summer instead of teaching summer classes (which is always a financial gamble anyway). Oh, here is my Patreon page—https://www.patreon.com/justphysics

So, that’s the idea. Here you can check out what I have so far.

Now for the questions. Here’s where you can help.

  • Should I start a NEW YouTube channel for these videos or just include them in my current channel. I’ll be honest—I thought it would be good to start a new channel, but I need a bunch of subscribers before I can put ads on the videos. Yes, that’s silly.
  • I started off with an intro to each video and included a title animation. Forget that—too much work. I don’t think people REALLY care about that stuff.
  • What about Patreon? What kinds of things should I put there? Should I include access to a discord group?
  • Titles. How should I title each video? Chapter 1 section 1 kinematics? Constant velocity? I’m not sure. What about homework videos (example problems).
  • I’m aiming for each video to be about 10 minutes long. Is that a good time length?

Finally, here is my tentative outline for videos.

  1. Kinematics in 1 Dimension (including numerical calculations).
  2. Forces and the Momentum Principle in 1D.
  3. Vectors
  4. Calculated Forces: gravity, springs, real gravity.
  5. Falling objects air resistance.
  6. Forces of Constraint: normal force, friction, tension
  7. 2D Motion: projectile motion, circular motion.
  8. Orbits.
  9. Work-Energy Principle.

That’s just a start.

Course Reflections: Physical Science (PHSC 101)

The Course:

This is a 3 hour lecture-based course for non-science majors. I used the super awesome Next GEN PET. I feel like I have talked about this curriculum a bunch (since it has content similar to PHYS 142—physics for education majors). Here are some key points.

  • Content based on the Next Generation Science Standards. For me, this isn’t such a big deal—but it can be for those adopting the curriculum.
  • This is an interactive lecture-based course. This semester, I started with 50 students.
  • Students are supposed to have a workbook that they write in. We have a textbook rental system though. In order to prevent the students from buying a book (which would be about the same price anyway), I had the bookstore make the workbook into a non-writable rental book.
  • The course covers: Energy, Forces, Waves, Light.
  • Students are presented with videos of experiments and then asked a series of multiple-choice “clicker” questions.

The Good:

Let’s be honest. Most courses for non-science majors don’t really help them understand the nature of science. Based on my own informal measurements in the past, students’ understanding of science decreases after the course. That’s bad. It’s probably because they just see science as a bunch of facts that need to be memorized.

This course focuses on the model building aspect of science. Students collect data (from the videos) and use that to justify a model—rather than just being told an idea.

The course also encourages critical thinking and uses student discussion during class. I feel like there were a good number of students that really got something out of the semester.

Oh, one more “good”. I am part of an FOLC (Faculty Online Learning Community) – https://nextgenpet.activatelearning.com/about/faculty-online-learning. My discussions with them were great.

Homework was better than I thought. I used the online activities that come with the curriculum and then I created “turn in” sheets for the students. These were simple questions based on the online stuff. Many students didn’t do it and some copied—but it helps them realize they need to do the HW.

The Bad:

Although the content is essentially the same as the studio-class version of the material, I don’t have much experience with the lecture version. Here are some other random notes about things that didn’t work out so great.

  • Clickers. I started off using the TurningPoint clickers (we already had these). For some reason, the receiver didn’t work on my macbook anymore (software update). Then later in the semester, they updated the PCs in the room and BOOM—clickers didn’t work there either. I eventually switched to plickers (https://www.plickers.com/library).
  • Student discussions. I need to get better at this part of the job (quote from Spider-Man: Homecoming). I just feel like there are small things in the class that can really throw off a class discussion. It’s tough. I need to start off with this more at the beginning and fight through the rough parts so that students get more accustomed to discussions.
  • Student participation. There are too many students that think they are watching a movie. They just sit there and play on their phone. I see them.
  • The workbook. I already mentioned that they didn’t really have a workbook. Towards the end of the semester, I started creating 1-2 page “notes” that had spots for them to write down the important stuff. A couple of students said they liked this.
  • Multiple-choice tests. I hate these.

The Future:

Here are the changes for the next time I will teach this course (next semester).

  • Change the content. I would like to cut out some of the activities and do more of the engineering-design activities.
  • Smaller room. Yes, I will be teaching the lecture-based course in the studio room. I would like to replace at least some of the videos with actual experiments.
  • One of my FOLC colleagues gives writing assignments. She tells the students to find some application of the content in real life. They have to submit a certain number of these and she just grades a few. I want to do this.
  • Plickers are better.

Course Reflections: Introductory Calc-Based Physics (PHYS 221)

The Course:

This is the calc-based physics course (the first semester). The students in the class are mostly:

  • Physics majors
  • Chemistry majors
  • Computer Science majors
  • Math majors

I don’t think there are any other students that take this. OK, I guess you could include pre-engineering—but technically they are still physics majors.

For the textbook, I use the super alpha awesome book Matter and Interactions (Wiley – Chabay and Sherwood). If you’ve read my stuff, you should know that I LOVE this book (and Bruce Sherwood and Ruth Chabay are both great people to talk to). Here is my previous review.

Just a few highlights of the curriculum.

  • Includes relativistic momentum and energy.
  • Focus on fundamental interactions and fundamental particles.
  • Ball and spring model of matter.
  • Three big principles: momentum, work-energy, angular momentum.
  • Explicit inclusion of numerical calculations.
  • I use Standards Based Grading with options for students to submit reassessment videos.
  • We often use multiple-choice questions in class with student response systems (clickers). Matter and Interactions has a nice set of questions to use.

Here is the course website.

The Good:

I always enjoy this course. The students are both diverse and great. They are at LEAST in Calc-I so that means they can probably do some algebra stuff. There are a good number of students that are in even more advanced math classes like Differential Equations and stuff. Oh, and it’s a great chance to get to know the new physics and chemistry majors.

The class isn’t too big (mine started around 30) so that it’s fairly easy to memorize names.

Maybe the best part of the class is watching student videos. OK, I really don’t like watching videos—it can get kind of boring. But I LOVE seeing students make terrible videos and then get better and start figuring things out. It’s awesome when students have never made a video and are afraid to do it, but then really get into it.

Students eventually figure out that I’m not just assessing their videos, but they are learning by making the videos.

One other thing I liked—I always like it: speed dating physics problem solving. Here is a twitter thread on speed dating (from another class).

Also, I did assign and collect homework. I didn’t really grade it (I gave them a score), but it’s like free points and maybe it helps them practice.

One last “good”. I put together this video tutorial on numerical calculations that looks at an object falling on the surface of the moon. I think it’s pretty good. Not sure how much the students used it though.

The Bad:

Yes, there was some bad stuff. Sometimes I felt like students were just sitting there. Even when I was doing interactive activities, they had this blank stare (it seemed). Maybe it was the class time (9:30 AM)—although that doesn’t seem too early. I really don’t know what the problem was. For the most part they were fine.

Another big problem—speed dating. Oh, I get it. Students don’t want to participate. They want to just sit there and take in the fire hose of learning (they think that works). But in the end, most of them seem to get some positive things out of the speed dating. But the room was not super great for this. It’s a standard lecture hall—so I didn’t really have places to put boards. I tried using very small boards, but it just wasn’t perfect.

One final problem—a good number of student just never seemed to fully grasp numerical calculations.

The Future:

Here are some ideas for the future.

  • Mounted white boards. If I have to be in that lecture hall, I want to find some ways to put boards somewhere around on the walls.
  • Plickers. I’m ditching the TurningPoint clickers. I’m tired of constant updates that bork the system. I get it—they want me to upgrade. Not upgrading again. Oh, also with Plickers it shows the student name over their head when they vote.
  • More in-class stuff. More group problem solving. More activities. More focus on numerical calculations.
  • I should show the students more of the awesome physics (like stuff from my blog). I don’t do this enough because I get so busy with getting through different topics—but I think the students really like these things. Who cares anyway, it’s the stuff that I love.

Course Reflection: Astronomy (EASC 102)

It’s the end of the semester, so that means it’s time to reflect on my courses. Why not just write this as a blog post? That’s what I will do.

The Course:

I’ve already talked about this course when I started the semester. So, here is a short review.

  • It’s a service course for non-science majors. There are no pre-reqs, so you can’t include much math.
  • The course was added late, there were only 13 students in the course.
  • I had a room that was more like a lab or a studio rather than a lecture hall.
  • As I said before, this is a tough class. The material seems fun, but it’s really deep. You can either cover superficial things—like known values of planets or you have to really get dirty. You can’t understand a star without knowing some important stuff about light and matter.

The Good:

The best part of the course was the flexibility. I could pretty much do whatever I wanted since they didn’t need anything from this course for future classes.

The other things that worked well were the labs. I mean, what the heck. Why not do a lab in the lab room? I started off with some of the University of Nebraska online activities—but I think these are too high of a level for my students.

After that, I went to make up my own labs:

  • Solar panels
  • Angular size
  • Parallax
  • I did a stellar properties lab – it was sort of a modified University of Nebraska lab.

I think the students liked the labs for the most part. Oh sure, there were a couple of students that just said “screw these labs—not going to participate” but there’s not much you can do about that.

Another thing I worked on was simplified presentations. The powerpoint slides that come with the textbook pretty much suck. They have too much stuff in them for the students to really learn anything. It’s not that my slides were much better, but I did include some of the online applets and animations in them.

Since the class was small, I had a better chance to interact with individual students. It’s always nice to get to know people. I admit that I didn’t learn names as well as I usually do.

In the last few weeks, I started using multiple-choice voting questions in class. I think this is the way to go. The questions I was using were probably too difficult for the students. Quick tip: use plickers (voting cards). When you scan the cards with your camera, it also shows student names.

Oh, one more thing. I think I did make some progress on student understanding of the nature of science. Really, this is the most important aspect of the course.

The Bad:

I already mentioned the bad powerpoints and the material is too deep. The other big problem—student understanding of graphs, math and stuff like that. It’s tough to do a lab that involves graphing when they can’t graph.

Although I had fun with the lectures, some students fell asleep.

The Future:

Let’s say I was going to teach this course again. What would I do? Here are some ideas.

  • Pick fewer topics. I think it’s best to stay away from stars and stuff. It depends on too many background ideas.
  • Do more labs. I would probably need to make the labs myself.
  • I think making some stuff that’s similar to PET would be perfect for this class. In fact, I did some labs like this for forces and waves.
  • I would like to do some type of project, but I’m afraid what the students would turn in.
  • DON’T USE the textbook or the powerpoints. They are terrible.

Intro Astronomy Update

I picked up this introductory astronomy course just a week before classes started. One of my other classes didn’t have enough students in it, so I got this instead. It’s a gen-ed science course for non-science majors. Since it was added late, there are only 12 students in the class.

I’ll be honest—there are some super awesome topics in this intro astronomy course. The historical stories and the “how do we know” stuff is great. HOWEVER, it’s also a really tough class.

I didn’t have time to build something from scratch, so I just went with the order and presentation of topics according to the textbook. This class uses Explorations – an Introduction to Astronomy, 9th ed (Arny, Schneider) McGraw Hill. It’s an OK, text with only a few areas that I don’t agree with. But let’s look at the first 4 chapters:

  • Chapter 1: The sky. Celestial sphere, motions of the sky, seasons, phases of the moon.
  • Chapter 2: Historical astronomy stuff. Mostly, this is the geocentric vs. heliocentric model of the solar system.
  • Chapter 3: Gravity and Motion. BAM. Forces and motion, gravity, escape velocity.
  • Chapter 4: Light and atoms. DOUBLE BAM.

Chapter 3 is bad. I mean, I have other classes that spend about 1/3rd of the semester on forces and motion and they don’t even get to the 1 over r squared version of gravity at any point. I think it’s possible to get students to understand most of the ideas in chapter 3, but not in a chapter-length amount of class time.

Oh sure. You could just tell the students everything they need to know about forces and motion. You could TELL them that a constant force makes an object have a constant acceleration. But research shows that this doesn’t really work. No, this is a tough concept and it’s going to take time to get it figured out.

Chapter 4 is even worse. The interaction between light and matter could be its own separate course. It’s not just a chapter. Oh, on top of that – there are these instructor power point slides. Here are three in a row that go something like this.

  • Light is an electromagnetic wave.
  • Light is also a particle.
  • Which way light manifests itself depends on the situation.

That’s bad. Of course you know I don’t like the whole “light is a particle” thing.

OK, but there are some good things about this course. I have a small enough class that I can put in some extra stuff. We did some of the NextGEN PET units in class, and that went over fairly well. I have also been doing some of the great online labs from University of Nebraska-Lincoln (https://astro.unl.edu/naap/). Those are nice.

One other quick note. I think I am going to skip over all the planet stuff. It seems like it would just turn into a “memorize the density of Saturn” stuff. I really want to get to stars. There are some great stories about how we know stuff about stars.

I’ll keep you updated on the progress of the course.

Jump Start Guide for Computational Physics

It’s the beginning of a new school year—and I’ve got you covered. You want to do something with coding in your physics class, but you don’t know where to start? I’m going to give you a jump start.

I know you are nervous, but don’t worry. You don’t need to be a ‘l33t h4x0rz’ (that’s cool-speak for elite hacker). You just need to get started. Just remember, everyone had to start programing at some point. They all did it—so can you.

What the heck do you call it?

I like to call this stuff “numerical calculations”. I think this is the best name for it because it sort of describes what’s going on. Here’s the general idea:

  • Take a physics problem (or any problem, really).
  • Break the problem into a bunch of small and easier problems.
  • Maybe make some approximations.
  • Solve all the small problems by using numbers.

Numbers are the key. You have to use numbers in a numerical calculation. The other solution is an analytical calculation. This is the process of solving a problem in terms of known functions—like the trig functions. For an analytic solution, you don’t really have to put in the numbers until the end.

Of course, there isn’t a huge difference in these two solutions (analytical vs. numerical). A great example from Bruce Sherwood (in a discussion at the recent AAPT meeting in Utah) points out the following:

Suppose you get a solution for a mass oscillating on a spring. The analytical solution will be in terms of the cosine function. But then, how do you get values for something like cos(0.33) = ? Well, you put it in your calculator or you look it up in a table. Oh, you could find the value for cosine by summing an infinite series. But you see—we are back to a numerical calculation.

That’s not exactly what Bruce said, but that’s the basic idea.

Here are some other names for numerical calculations that you might see:

  • Computational physics
  • Coding in physics
  • I’m drawing a blank here—there must be some other words.

But I also like numerical calculations because it doesn’t explicitly say “computer” in it.

Why do numerical calculations in physics?

Solving for the motion of a mass on a spring

Let me be brief and just list some points.

  • Numerical calculations are just part of physics. There are countless physics problems that can only be solved numerically.
  • Once students get the idea of numerical calculations, they can solve more interesting problems that would otherwise be inaccessible to them.
  • What about other fields? Meteorology, digital animations, protein folding, economics…the list goes on.
  • Tools. The tools for numerical calculations are both free and easy to access. You don’t need to install anything and you could even do it on a smart phone (not recommend—but possible).
  • Finally, numerical calculations helps student understand physics. I’ve always been surprised that when working on a problem with students on a computer, they ask questions. But these questions are rarely about computer syntax. They are usually things about vectors or forces. It’s awesome.

Who is this for?

I’m going to get you started—so this tutorial is geared towards very introductory classes. I use this same stuff in a physics lab for an algebra-based physics course at that college level. I think this would be fine for high school classes also.

If you want more advanced stuff—this might also work as an introduction. For my calculus-based physics course, I start with more complicated stuff.

Also, I am careful to emphasize that students (and faculty) don’t need any prior experience with coding.

Where to start

I like to have a workshop format for my lab or class. I use a projector at the front of the room to go over some points and then stop and let the students work on code either individually or in groups (here is a version of my presentation—feel free to use it). I tell students to bring a computer or tablet if possible. Otherwise they will be in groups of 4 per computer (which is not ideal). Of course some students don’t want to get involved, so a 4 person group is what they want.

Here is the general outline of the workshop format lesson.

  • Give an overview of numerical calculations (motivation).
  • Start with an object moving at a constant velocity in one dimension. Let them solve it analytically (hopefully, this is a review).
  • Next have them take this SAME PROBLEM but solve it by breaking into 7 time steps—but still solving it on paper. NO COMPUTERS YET.
  • I actually give them a table to fill out. It has 7 rows with columns for time, time step, and position. After a short time, I stop them and go over the calculation for the first row (and maybe the second). Some students can finish this table very quickly, and others not so quick.

Next, they do this same set of calculations with some python code. I give them this program that runs as it is and I go over each line.

The two parts that might be new for students:

After going over the code, I send them to this page (https://trinket.io/rhettallain_gmail_com/courses/physics-python-for-mere-mortals#/beginning-numerical-calculations/using-small-pieces). It’s a trinket.io page with the code right in the browser. They don’t even need to log in or anything. It even has all the instructions there too so that they could do this on their own. The trinket site is the BEST. Oh, I also made this shortened-url (http://bit.ly/trinket-physics). That page includes everything. I make sure to tell them to click on the “using small pieces” tab on the left to get to the code.

So, the students run the code and then modify the code to answer some questions such as:

  • Where will the car be at a different time? Say 2.2 seconds.
  • What if you change the velocity the 0.62 m/s, where will it be after 2.2 seconds?
  • What if the car starts at -0.5 meters?

Stuff like that. Really, I just want them to be able to run the code, read the output, and change the code. It’s sort of a coding ice-breaker.

I’m not going to go over the rest of the workshop—but it’s all there (and more) on the trinket.io site along with the instructor slides. After that first small activity, the students do the following:

  • A similar problem but with a constant (non-zero) acceleration. This is great because you get a different final answer for the numerical calculation that depends on the size of the time step.
  • How to make graphs (or at least print out values) so you can get more data.
  • Solving a problem with two cars—one moving at a constant velocity and one accelerating. This is the classic “police chase” problem. I set up the program (not all the way) but I let them figure out how to change the while loop to get it to run. It’s great because students come up with their own ways of making it work. Sometimes, this is where I stop the class.
  • Projectile motion.
  • Mass oscillating on a spring.

What do you need?

If you want to do this in class, you need some computers or tablets and some time. You could probably do this in sections, just break it into 30 minute activities if you like.

Some other things to consider:

  • Make sure you work through the material first. It’s important to really know what’s going on so that you can easily help students when they get stuck.
  • If a group has a program that’s not running right, I really try to get them unstuck. If it’s a silly syntax error, I try to find that right away so they don’t get frustrated.
  • If you have any questions or need help. let me know.

What’s Wrong With Algebra-Based E&M?

It’s summer time. For me, that means I’m getting ready for summer classes. Yay! Well, at least I get paid—so that’s good, right? This year, I am teaching the physics for elementary education majors and the second semester of algebra-based physics (electricity and magnetism).

Just to be clear, there are usually two types of introductory physics at the college level. First, there is the calculus-based physics sequence. This course is for physics majors, chemistry majors, math majors…stuff like that. Of course it assumes that the students can use calculus.

The other version is the algebra-based. It does NOT use calculus. The students that take this (at least at my institution) are mostly biology, engineering technology. If you want to consider the course goals, you really need to know who is taking the course.

In order to see the problem with the algebra-based course, let me describe the second semester of the calculus-based course. For this course, I use Matter and Interactions (Chabay and Sherwood, Wiley). It’s a great textbook—here is my review of this textbook from 2014. Here is a short summary of the approach (for the second semester).

  • What is the electric field?
  • What is the magnetic field?
  • How does matter interact with the electric and magnetic fields?
  • What is the connection between electric and magnetic fields—Maxwell’s Equations.

For me, it’s all about building up to Maxwell’s Equations. Just to be clear, here are Maxwell’s Equations.

\oint \vec{E} \cdot \hat{n} dA = \frac{1}{\epsilon_0} \sum q_\text{in}

\oint \vec{B} \cdot \hat{n} dA = 0

\oint \vec{B} \cdot \vec{dl} = \mu_0 \left[ \sum I_\text{in} + \epsilon_0 \frac{d}{dt} \int \vec{E} \cdot \hat{n} dA \right]

\oint \vec{E} \cdot \vec{dl} =- \frac{d}{dt} \int \vec{B} \cdot \hat{n} dA

Of course there are many different ways to write these equations, however—one thing should be clear. You can’t really grok Maxwell’s Equations without calculus. You need to understand both derivatives, line integrals, and surface integrals.

Now for the algebra-based course. If you don’t have calculus, you can’t really get to Maxwell’s equations. Oh sure, you could do things like Gauss’s Law and Ampere’s law, but it would just be a “how do you use this equation”. Although it’s still true that Maxwell’s equations are sort of magical, without calculus they are just a game.

It’s sort of like teaching long division to 5th graders. Sure, they can learn the process of finding a division value but using the steps—but why? Why use long division when you could just use a calculator? However, if you use long division to understand the number system and division, that’s cool. But it seems that most classes just teach the “how to long divide” without going into the details.

This is exactly where most algebra-based physics textbooks end up. It becomes a giant equation salad. A bunch of equations that have no derivation. Yes, students can be “trained” to use these equations, but I really don’t see the point of that.

I should point out that there isn’t a problem in the first semester of algebra-based physics. A student can use the momentum principle or the work-energy principle without calculus. It’s not a big problem.

OK, so what am I going to do? Honestly, I don’t know. Here are some final thoughts.

  • What is the ultimate goal of this course? Why do biology and engineering technology majors take this course? The course goal will shape the course material.
  • I have two options for textbooks this semester. They both suck. OK, they don’t actually suck—but they are just a bunch of equations.
  • It would be nice to just focus on observable stuff and modeling. Do something like measure current and voltage and produce a linear function relating the two. Oh, how about repeating historical experiments to see where all this stuff comes from?

I’ll keep you updated.

Evolution of a Physics Lab

When I think about the physics labs I teach, I realize things have changed over the past 18 years. The way that I run introductory labs is different than when I first started. Here is a review of my lab philosophy over the years.

I’m going to leave off the labs I taught as a graduate student since I wasn’t really in charge of the lab design.

Phase 1: Mostly Traditional – But With Computers

Really, when you first start off with a tenure track position you have to go with the flow. You can’t jump in and start doing crazy stuff. There are too many other things to focus on (grants, papers, projects…). So, for me—I just took the departmental physics lab manual and started with that. It was pretty traditional.

But I quickly set out on my own. I stopped using the lab manual and made my own labs. Oh, they were still pretty traditional in the format of:

  • Here is some physics theory.
  • Here are detailed instructions on how to collect data.
  • Here are detailed instructions on how to analyze the data.

However, my labs had data acquisition stuff to make it cooler. I found some money to put new (at the time new) iMacs in the room and used Vernier Logger Pro with sensors and stuff. Wait, I actually have a picture of this room from 2003.

Check that out. Those are some classic iMacs. Those suckers were in use for at least 10 years.

There was another important aspect of this “phase 1 lab”. I wanted to have the students work on the following:

  • Physics concepts
  • Data analysis
  • Error analysis (uncertainty)
  • Technical writing and communication
  • Experimental design.

Note: you can not do this many things. It’s either a 2 or 3 hour lab. At most you could focus on two of these things.

In terms of writing, I think I was making excellent progress on this front. I was working on an idea about peer evaluation of writing. The basic idea is that students evaluate other students writings as a way of helping everyone write better. I still think this is a good idea, but I moved on (because of many issues and other things to work on).

Phase 2: Make Pre Lab Great Again

If you have taught labs, you know that students aren’t always properly prepared. Most faculty know this. They might spend the first 30 minutes of lab time with a lecture to cover the important points. But this still doesn’t work. It’s hard for the students to pay attention and to fully grok the lab. They end up just asking questions about stuff you just told them.

OK—I can fix this. I will just make super awesome lab materials and post it online. Note only that, I will include videos and everything. Students will look at this and then we can just rock and roll during lab.

Nope. That doesn’t work. It doesn’t matter how great the video teaches the concept if students never watch it. In fact, I would find many students watching the video IN LAB. This drives me crazy—mostly because I hate hearing my own voice.

I tried online pre-lab quizzes. That didn’t work. They would just do the bare minimum to get the stuff done before class. It was just a pain in the rear.

Oh, what about pre-lab quizzes in class? Again, those are more trouble than they are worth.

Phase 3: Play and Compete

This one works fairly well. Forget about the pre lab stuff. Drop the lecture at the beginning of lab too. Give the students stuff to play with and see if they can come up with their own questions.

Here is an example in the realm of 1-D collisions.

  • Show students the tracks, carts, and different bumper options.
  • Tell them “keep the track level”, but otherwise just play with it.
  • Students love the magnetic bumpers. Many of them will try collisions between different mass carts.
  • After they have played, suggest they try to calculate the kinetic energy and the momentum of the carts.
  • Let them come up with their own methods for calculating velocities (I give some options).

That works fairly well. Some students don’t do too much, but for the students that find cool stuff it works great.

Here is another example with a competition. Again, no pre-lab.

  • Show students an inertial balance (oscillates back and forth).
  • Let them play with it.
  • Now for the challenge. Can you use this to find the mass of 4 unknown masses? The quiz at the end of the lab is just finding the mass. Your score is based on your accuracy.

This works fairly well—but not every lab can be in the form of a contest. However, students love to compete and it’s fun.

Phase 4: Free-for-all

This is where I am at now. I don’t expect students to prepare for lab because I will just be disappointed. The labs are a combination of all types of lab. Sometimes they are just verifying an equation. Sometimes they get to build stuff. I don’t expect the lab to match up with the lecture course (because apparently that doesn’t matter).

Sometimes labs still suck, but sometimes they are awesome. I will keep changing my labs until everything is perfect.

Oh, here is a more recent picture of the lab.

Analysis of a borked lab

It happens all the time. It even happens to you. There is a new lab you want to try out—or maybe you are just modifying a previous physics lab. You are trying to make things better. But when the class meets—things fall apart (sometimes literally).

Yes. This is what happened to me this week. And yes—it’s OK.

But let’s look at the lab and go over the problems so that I can make it even better for the future.

Finding the electric field due to a point charge

This is a lab for the algebra-based physics course. It’s always tough because many of the first things they cover in the lecture class don’t have lab activities with things you can measure. Oh sure—there is that electrically charged clear tape lab, but it will be a while before they get to circuits.

So, my idea was to have the students use python to calculate the electric field due to a point charge. This would give them a safe and friendly introduction to python so that we could use it later to get the electric field due to other things (line a dipole or a line charge). It would be great.

Here is the basic structure of the lab (based on this trinket.io stuff that I wrote – https://rhettallain_gmail_com.trinket.io/intro-to-electric-and-magnetic-fields#/introduction/vector-review

You can look at that stuff, but basically I give a workshop style presentation and have the students do the following:

  • Review vectors. Add two vectors on paper (not with python).
  • Find the displacement vector – given the vector for a point, find the vector from that point to another point (the vector r).
  • Find the unit vector and the magnitude of a vector (using python).
  • Next, find the electric field due to a point charge for the simple case with a charge at the origin and the observation point on the x-axis. Do this on paper.
  • Now do the same calculation with python.
  • Find the electric field at some location due to a charge not at the origin (in python).
  • Use python (or whatever) to make a graph of the electric field as a function of distance for a point charge. Graph paper is fine. If they wanted to, they could do the calculations by hand (or use python).
  • Finally, give a quick overview of the sphere() and arrow() object in glowscript.

So, that was the plan.

Lab problems

Here are the problems students had during this lab.

  • Computer problems. Yes—whenever using computers, someone is going to have a problem. In this case, it was partly my fault. There was one computer that was broken and some other ones weren’t updated. Honestly, the best option is for students to bring their own.
  • I can see that there are some students that just sort of “shut down” when they see computer code. They automatically assume it’s too complicated to grok.
  • Students working in big groups. I hate having 4 students use one computer. That’s just lame.
  • Too much lecture. The first time I did this, I spent too much time going over vectors with not enough breaks for students to practice. I partially fixed this for the second section of lab.
  • Some students were just lost on vectors.
  • Yes, the unit vector is a tough concept.
  • I’ve learned this before—but I guess I need to relearn. The visualization (sphere and arrow) are just too much for many students. That’s why I moved it to the end in my second section.

So, that’s it. I am going to rewrite the lab stuff on trinket.io. I am also going to change my material for the dipole stuff that they are doing next week. Hopefully it goes well. Let’s just see.

Should We Even Be Offering Online Classes?

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It’s probably clear—I’m not a fan of online classes. Honestly, I very surprised out how much emphasis universities put on creating MORE online classes.

However, I’m ready for you to change my mind.  Let me offer my thoughts and then you can leave a comment or reply on twitter. Seriously—change my mind.

Learning is about doing

Let me start with my fundamental idea about the nature of learning.  You can’t learn if you don’t do.  OK, I will stop you right there.  Here is what you are going to say (or at least one person will say this):

I don’t buy this learn by doing stuff.  I spent a bunch of years learning physics and we just had a textbook along with traditional lecture. It looks like I turned out just fine.

Yes, you turned out fine—but what about everyone else?  Anyway, I still think you learn by doing.  Some humans are pretty good at watching a lecture or reading a textbook and then engaging in the material in some way—maybe just inside of their heads.  I don’t know.

But here is real truth.  No one learns real stuff (like physics) by just watching a lecture or a video or a presentation.  There is no short cut to real learning.  It takes effort and struggle.  It is through this struggle (in our minds) that we change and learn.

What are these “learn by doing” things that could happen in a course?  Here are just a few examples. I’m using an example of a physics class.

  • Work physics problems—as homework, or tests, or group work or whatever.
  • Interactive questions.  This could be clicker questions in class or conceptual physics questions such as physics tutorials or something.
  • Ranking tasks.  Students get several options for a question and they have to rank them.  Many more ideas at PhysPort.
  • Card sort or speed dating problems (pretty much anything you see on Kelly O’Shea’s site).
  • Find the error in someone’s physics solution—I think this is also from Kelly.

OK, you get the idea.

Can you “do stuff” online?

Yes. I believe that it is technically possible to have an online course that engages students.  It has to be possible, but I’m not sure exactly how this would work.

Maybe I’m old, but for me it’s like having a video conference?  Have you ever been in a video conference?  Surely you have.  What happens when there are perhaps 4 or 5 people in the conference and there is that ever so slight delay in communication?  I don’t know about you, but for me it ruins everything.  I can’t stand it.  It seems like it would be the same as talking face to face, but it isn’t.

This is how I feel about online learning—it seems like you could do all the things I listed above but do them online.  It just doesn’t seem to work as well.

Oh, and if your online class just takes the powerpoint lectures you use and puts them online—that just seems silly.  Honestly, why are we still using powerpoint stuff that just covers the same material as the book?

Is the future of learning online?  

Maybe.  Who knows.  Maybe I’m just resisting change that will happen anyway.  I’ll say this—if the goal of learning is just to transmit information, then what the heck are we doing in class?  Wikipedia already does this better than I can.

Two links:

Why are we trying to compete nationally? 

Let’s just focus on local.  We can win at local.  If we (the university) want to compete online, aren’t we competing for students that could use MIT’s online programs or some other online university that does a better (or cheaper) job than us?

I’m not against videos.

In case it’s not clear, I have been putting educational videos online for a long time.  A long time.  Here is one from 2009.

My feeling is that if there is a short lecture or demo I could do in class, I might as well put it online.  That way students can watch it and rewatch it (and other people can use it too).  These videos then allow me to do more active-learning things in class rather than going over the solution to some physics problem.

But I don’t think you can just put a bunch of videos online and say “boom – online course”.  If you think that, what about just posting the textbook online and calling it a course?  It’s essentially the same thing.

What do students think?

Sometimes I talk to students. I ask them what they think about the online courses that they take.  Here are some things they say:

  • I like the online courses—especially for intro courses.  That way I can get it over with and do the work from home.
  • I hate online courses.  I get super confused and it’s really hard to learn.

I could be wrong, but it seems as though they like online courses for simple stuff but not for complicated courses.  Courses that are just a bunch of facts work great as online courses but not something like physics.

Perhaps we have too many courses that are just a collection of facts.  Yes, some of these courses are necessary—but it should just be a few.

Focus on community of learners.

Let me share my chocolate chip cookie model for higher education.

College is like a chocolate chip cookie.  The courses a student takes are like the chocolate chips and all the other stuff they do between classes is like the cookie dough.  What if you put all the courses online?  Then you just have a bunch of chocolate chips.  You might like that, but it’s pretty hard to call it a cookie.  Personally, I prefer the whole cookie.

The most important part of college aren’t the classes—it’s all the other stuff.  The goal of higher education is to build a community of learners (where the faculty are also learning stuff).

The end.  Change my mind.