August 31, 2016

Day 7 - PHYS 201

Today in Physics 201 the 8:00am section finished up the TST activities and then did some nTIPERs related to the 1-D motion.

In the 10:00am section we looked at python for the first time.  I stole material from Rhett Allain's introduction to coding - starting with the class looking at constant velocity and constant acceleration motion.  We used, which I think I'm going to stick with as long as possible.  Here's the code we started with:

One note - there was a bit of trouble running the code on the classroom laptops. I'm not sure if it is becuase we use Internet Explorer or because I chose to use GlowScript instead of straight python. I'll need to look at this more.

August 30, 2016

Day 6 - PHYS 201 and PHYS 110

Today in Physics 201 we continued with the TST activities from yesterday.  The 8:00am section started them, and the 10:00am section finished them.  In the 10:00am section we did a few more TIPERs after completing the lab activity.

In Physics 110 we looked at the data from the PhET simulation. Students were shown how to plot force vs. stretch distance. The goal I was heading for was developing the idea of a spring constant and Hooke's Law  I wanted to try to make the analysis more real to try to illustrate what we are trying to measure.  So I had this set up (thanks to our awesome lab prep staff!) in the lab:
Springs with identical hanging masses.
The springs all had the same masses hanging from them, thus the same force.  Students easily understood that the spring with the least amount of stretch was the hardest (in terms from the PhET simulation) and the spring with the largest stretch was the softest spring.  We will follow up on Thursday to see how the understanding is progressing.

Day 5 - PHYS 201

(Day late...oops.)

Today in Physics 201 we got the 8:00 am section caught up with the calculus-based derivations of the kinematic equations.  The 10:00 am section asked some questions from the homework which led right into the "Tools for Scientific Thinking" activities which involve students walking in front of the motion detectors.  We only do the first 3 of these activities.  With some encouragement and bit of pushing, most of the groups got through the first two activities in a little over an hour.

Students working on the "Tools for Scientific Thinking" activities.

A better way to give practice problems?

Is it better to do traditional physics problems...or would there be value in structuring problems so that the answer is stated in the problem?

For example, when I think of a "traditional" physics problem, I think of something that looks like this:
If air resistance is negligible, determine the maximum height (above its release point) of a ball that is thrown straight upward which is in the air for a total of 3.0 seconds. 
But, what if the problem were stated more like this:
Show that when air resistance is negligible, a ball thrown straight up that is in the air for 3.0 seconds reaches a maximum height of 11 meters above its release point.
In my mind, the second version explicitly puts emphasis on the process and the reasoning behind the process, whereas the traditional problem naturally emphasizes the answer to the question.  I can see this way being done in the classroom setting, for homework practice as well as assessment purposes.

What am I missing here?  Why isn't this done for intro physics classes?

August 29, 2016

Embedding PDFs in a LaTeX file

Have you ever wanted to embed a PDF inside a larger LaTeX document?  For my "Book of Infinite Learning" I wanted to embed a copy of two different journal articles.  I didn't want to just grab the text and redo the layout of the articles.

Fortunately, there is a LaTeX way to do this.  Here are the commands I used:
\includepdf[pages=-, fitpaper=true]{filename.pdf}
The heavy lifting is done by the \includepdf command from the pdfpages package.  Read up on the options for that command if you don't want to use all the pages in the file.

What really made my day was the ability to change the margins for my LaTeX document for just the PDFs I wanted to embed.  Using \newgeometry I can specify smaller margins for these pages, since the PDF already has plenty of margin spacing.  Then \restoregeometry reverts back to the document margins.

I'm very happy with how this turned out.

August 26, 2016

Do you know about booklet printing?

I need to make a confession. I may have a problem.

I'm addicted to booklet printing. 


Last Spring at the start of the term I was fretting about whether to give paper copies of my syllabus or stick only with the online version. 

I may be kidding myself, but I am trying to use a well-formatted layout for the syllabus so that it is easy and welcoming to read. I know not all students will read it, but I want to remove as many barriers as possible. 

The real issue was the page count. I had 80 students and an 8-page syllabus to hand out. Even double-sided, that's a lot. 

Enter booklet printing. 

It's an option on Adobe Acrobat to print foldable booklets. That puts four pages on a single sheet of paper. What's that? You don't want to hand out super small booklets made on standard sheets of paper? Print on legal paper - then each page is 8.5" by 7". 

I do TIPER packets this way and other random handouts that I create for my classes. Now practically everything is booklet printed. We save paper and the multiple sheets are easier to keep together. 

What do you booklet print?

August 25, 2016

Day 3 - PHYS 201 - No class

(This was supposed to be published yesterday, but I wrote it on the plane home and the on-board wifi wouldn't let me publish it, so it was shoved into a drafts folder.)

We did not have class today because I was at the Office of Science and Technology Policy at the White House. Technically, the meeting was at the Eisenhower building - which is where the majority of the President's staff work every day.


Day 4 - PHYS 201 and PHYS 110

Today in PHYS 201 we connected the motion diagrams to graphs and introduced concepts: position, displacement, average velocity and average acceleration. We also discussed the connection of the slope of a graph and that taking a limit as the time interval becomes small leads to an instantaneous velocity or acceleration. The 10:00 section was able to use calculus to go from a constant acceleration back to an expression for position as a function of time.  That section also got the first packet of nTIPERS.

The PHYS 110 class started by looking at the class data from the previous mini-lab. It was not as clean as I'd hoped, but we talked a bit about variance and uncertainty in data and how to improve that.

Then we followed that discussion up with one of my favorite demos - taking a set of 5 balls of various sizes and masses and challenging the groups to order them by weight.  The key to this demo is that there should be a small steel ball which weighs LESS than a larger foam ball.  Most groups will say the metal ball is the heaviest.  Today there were two groups that said the foam ball was not the lightest, but the other four groups said it was.  Students are amazed to learn the foam ball is the heaviest and the steel ball is less massive than two of the balls (at least) in the set.  It is a dramatic illustration of the body's sensitivity to pressure.

After finishing up the intro to basic physics, we started on Simple Harmonic Motion and got through part of the PHeT demo on Masses and Springs as a mini-lab

Masses & Springs
Click to Run

August 24, 2016

The physics of steadicams - a lab idea?

I recently heard a podcast on the design and operation of steadicams by the excellent Stuff You Should Know podcast. The podcast took much of the information from this article: How Steadicams Work | HowStuffWorks.

The part of the article that caught my eye the most was this:
Increasing the object's moment of inertia makes it harder to shake the camera unintentionally. One way to increase the moment of inertia would be to add more weight to the camera system, but this would make things harder for the cameraman. Instead, Garrett Brown decided to take the existing components of the camera and spread them out. This increases the distance between the axis of rotation and the mass of the total camera assembly, making the camera more resistant to rotation.
I wonder if it would be possible to develop a physics demonstration, or better, a lab based on the physics of the steadicam.  I know there are some consumer-grade steadicam mounts, but I'm not sure if those would be useful for a physics lab.

I'm just brainstorming here, but what if there was a lab where students had a goal of developing a steadicam mount for either their phone or a camera that we have in the lab. There might be constraints on the construction or mass of the mount and/or some sort of guidelines on the assessment of the effectiveness of the mount.  Or maybe what would be even better is if students developed their own methods of assessing the effectiveness of the mount.

I'd love to hear your thoughts and ideas related to steadicam physics.

August 23, 2016

Day 2 - PHYS 201 and PHYS 110


Today in Physics 201 we looked at the motion diagrams posted on the New York Times website as an introduction to 1-D motion. 

Then I challenged the class to make their own motion diagrams using a blinking LED on an arduino captured with a long exposure photo. My idea was to use the exercise as way to have a goal, try something out, analyze the results and iterate until reaching the desired outcome. I think it worked all right, but I wish we had more time. 

In Physics 110 we introduced ourselves to each other and then started getting into the basic physics material. I passed out the syllabus and went through that. 

We got all the way through the first "mini-lab" I had set up, which was finding the acceleration of the IOLab carts going down a small ramp. I realized as the class was doing the lab that I have no idea how to save the data. Oops. Going to need to figure that out!  

August 22, 2016

Day 1 - PHYS 201

Today in PHYS 201 we did this excellent activity which was linked to on twitter.  I'm glad I saw it and tried it out with the classes, because I had run out of time after having the class do the FCI and handing out the syllabus.  Having only 90 minutes each day is going to make each day seem tighter, but I think overall it will be better.


Acoustics videos by the Smithsonian's American Museum of Natural History

I only recently discovered that the American Museum of Natural History has a few videos on acoustics.  These videos are short and pretty good. They all have native captions in the videos, which is a great feature.

The above video shows off quite a few historical scientific devices for studying acoustics, but other than mentioning a wave machine, does not really discuss much about the specific devices. My question: how many examples of the devices shown are still being used in labs and classrooms around the world?

The second video in the series is about the concept of waves and the propagation of sound as a wave. Again, the video is short, but the science is solid.

The third video is all about tuning forks. I think the science here is a little less well done, although it is passable for introductory level acoustics.  That said, there's not a whole lot of interesting or relevant science being conveyed in this video. Some interesting history, but that's about it.

The fourth video is about Chladni's demonstration of mode shapes of vibrating plates. This video is really short.

The last video in the series is an introduction to the idea of resonance. Here, I think the science is not great. It's not exactly wrong, but there is no solid explanation or definition of resonance given which gives the impression that the examples cited are two distinct types of resonance. I think I would show this video to my class after our resonance discussion and ask them what they like and don't like about the video.

There are more videos, but they are all demonstrations of the artifacts shown in the above videos. See the playlist here:

Finally, if you want to see more about the devices shown in the videos, there is information on the museum's website.

August 19, 2016

All my students are getting a book on learning this term

From this past summer's physics teacher camp website, I caught this excellent list of readings on teaching and learning:

There was a bit of overlap between this list and a series of articles, infographics and other material that I have compiled into a booklet I am affectionately calling the “Book of Infinite Learning”.  The learning is what is infinite; the book is not.

I compiled all the articles together and printed them in booklet form.  Of course, I have no rights to these articles, so I can't share the books beyond my classroom, but I can share the links to the articles that went into this booklet.
Here’s a partial list of all the articles I’m giving my classes this Fall:

  1. How Does the Brain Learn Best? Smart Studying Strategies -
    This article is from the Mindshift blog on KQED’s website.
  2. The art of back-of-the-envelope calculations -
    From FermiLab’s Symmetry Magazine.
  3. Bigger Gains for Students Who Don’t Get Help Solving Problems -
    Another article from the Mindshift blog.
  4. What It Feels Like to Be Bad at Math -
    This article is from the incredibly brilliant Math with Bad Drawings blog.  Check it out!
  5. Failures, Mistakes and Other Learning Tools -
    This is a post from the Adventures with the Lower Level blog. It really spoke to me when I first read it.
  6. Learning goes through The Land of Confusion -
    Great short piece by Rhett Allain.
  7. The Key to Science (and Life) Is Being Wrong -
    From one of the Scientific American blogs.
  8. Multitasking while studying: Divided attention and technological gadgets impair learning and memory -
    An article from Slate.
  9. The Big Lie About Student Achievement -
    From Huffington Post.
  10. Telling You the Answer Isn't the Answer -
    Another piece by Rhett Allain.
  11. Two Common Misconceptions About Learning -
    Yet another piece on learning by Rhett Allain.
  12. Confuse Students to Help Them Learn -
    This piece is from The Chronicle of Higher Education. It highlights Derek Muller’s physics education research work.
  13. How ‘Deprogramming’ Kids From How to ‘Do School’ Could Improve Learning -
    Another piece from the Mindshift blog.
  14. Re-reading is inefficient. Here are 8 tips for studying smarter. -
    From  Out of the 8 tips, there are a couple I don’t fully agree with, but the others are really good. The article as a whole is a great discussion starter.
  15. O Adjunct! My Adjunct! -
    From The New Yorker.  Our students need to know about precariat faculty.
As you can see, I have a few favorite sources that I have drawn from over the years - Rhett Allain and the Mindshift blog, especially.  All the articles are things that others have shared with me on twitter over the years.  I'm always excited to get to share them with students - bring on this new term!