Deceptively Simple Demos

We’ve all been there, right? We see a demo on YouTube and it looks perfectly simple, until…we try to recreate it. Even though I have performed many demos over the past ten years as a physics teacher, a “simple” demo is not always simple.

Recently, I tried to recreate a “Simple Photoelectric Effect Demo.” I was hoping to include it in one of my videos for new physics teachers. Almost an hour later, I still could not get the demo to work like the person in the video!

Remember that the video you see online is the best shot of what could be many failed attempts at creating the exciting effect of the demo you are watching. Do not give up if recreating the demo is not easy at first. Sometimes, you can ask a colleague for tips, or even look up tips for how to recreate the demo on the Internet. It might be possible to find advice relating directly to the demo you are observing. I found some advice about the photoelectric effect demo here: http://www.aapt.org/Programs/contests/upload/beehler.pdf 

and then I modified the materials I was using to try to improve my attempt at the demo.

For all of these reasons, before attempting the demo in front of your class, you should always try it out yourself. That way, you won’t waste class time if things go wrong and you won’t end up feeling frustrated or embarrassed in front of your class.

Here is what happened to me in detail: I watched the video for “Simple PhotoelectricEffect Demo.” This demo looks awesome and it was presented at a national meeting of the American Association of Physics Teachers (AAPT)! 

The demo uses a soda can, wire, tinsel, and a germ-sanitizing  UV-C light (which can be purchased online or at a local drugstore). 

As I said before, after multiple attempts, my demo was not working like the one onscreen.  

I realized that while I was using similar materials to what I saw online, I needed to use the exact materials (such as a wire instead of a nail and sandpaper instead of steel wool to rub the soda can) to create a successful demo. On another day, I finally located all of the necessary materials, and I was eventually successful in creating this demo—after more than an hour of trial and error.

This whole process made me think about the following question: When should you give up on a demo? 

Any thoughts, all of you teachers out there? Are there times when you should just play the video for your class instead?

Ultimately, the decision is up to you. It depends on how much you like to experiment and how much time and patience you possess.

If you cannot recreate a demo after watching on YouTube, you are not alone. Part of the experience of being a physics teacher is spending the time with the materials in your lab, getting to know your equipment, trying, failing, and persevering. Even if your demo is not dazzling on the first try, I hope you will still continue to integrate demos into your instructional practice and use visuals and interactive components in your physics teaching as much as possible.

Engaging Students through the Production of Student Films

As I mentioned in the previous entry, I taught a two week enrichment course for high school students about creating science films. 

Students engaged in the filmmaking process from pre-production to production to post-production. I wrote an article to advise teachers who are interested in creating movies with their students. 

This article includes advice on the three stages of film-making as well as five methods of engagement to use in the videos. I also share advice about storyboarding and scripting and additional resources for teachers to use. 

The students in my class worked on the script, storyboards, and of course, acted in the videos as lively hosts. 

Below is a still from the "Why is the Sky Blue?" video. Two student hosts scatter coffee creamer in an aquarium to show the appearance of blue light.

The article was published in the SCOPE: Curriculum Studies Newsletter, a publication of the National Association for Gifted Children, and is titled: "Engaging Students through the Production of Student Films: Advice for Successful Movies" Click on the title link above. 

If you read the article, I hope you will learn a lot and that you will consider creating science videos with your students. 

Why is the Sky Blue?

Why is the sky blue?

Does the sky reflect blue light? Does it only let blue light pass through? Does it emit blue light like a glowstick?

Many people have asked this question, but we don't always receive a full or accurate answer. During a two-week immersion course, a group of my high school science students created this video entitled, you guessed it, "Why is the Sky Blue?"

Vintage Physics Illustration

Falling Balloon and Two Types of Air Resistance

A piece of advice for all of you science teachers out there...try out a lab at home or in your classroom before presenting to the class. Here I am working on the falling balloon lab. My advice in this lab I created was to include a coin in the lip of the balloon and drop it. However, soon, I found the coin was too heavy and decided to change to paper clips. One paper clip weighs about 1 gram.

This lab is about air resistance, including laminar and turbulent air friction. I have noticed that many labs only consider air resistance as an experimental error. However, it is not hard to create a lab focusing on air resistance using household materials, which will work for either an Algebra or Calculus-based Physics Class.  I am still editing the lab, but I will share it soon!

 I like to try out each lab with students a few times before sharing my labs with other teachers, and so far the students have enjoyed the lab and learned a lot, using only a few simple materials, including:

·         Several balloons
·         Meter stick
·         Stopwatch
·         Several coins or paper clips
·         Gram scale

Trying to capture another falling balloon drop...

sorry, I did not have my slow motion camera with me!

I hope this entry will inspire you to think about household materials that you could use in a simple physics lab in your classroom. Applying your creativity to creating new labs or demos can keep your teaching fresh and exciting.