High (Voltage) Wire Act

My brother-in-law Peter visited last year and showed me and my wife some of his favorite short videos on YouTube. When I saw this one featuring a man inspecting high voltage lines, I knew that I would show it to my students. It's a lovely little video narrated by the electrical inspector who talks about his work, and his life, and even tells a story about how his suit is a special kind of Faraday cage.

I knew my students would find this video interesting. There are a lot of intriguing electrical details and small events that could almost go unnoticed, and which could form the basis of some interesting physics questions and demonstrations. Our technical school has an Electrical Technology shop, and students in the shop would already know about this kind of work, and would be excited to watch this and share their knowledge. This video is a perfect example of what I like to add to my instruction toolkit.

The version I first watched on YouTube was of poor quality, and there was no indication of who actually made the video. It was obviously clipped from a longer video about dangerous or exciting work. There are many copies scattered throughout YouTube, and I spent a lot of time hunting for the best and most complete version. I finally found a high-definition version of the clip. I used Filmora to clean up the beginning and the end of the audio track. I did watch other videos about high-voltage line inspectors, but this one best suited my purposes. It's calming, actually, rather than all hyped up, and you get a sense of the man rather than just a focus on the details or the danger of the job. The music sets the mood perfectly. There's a joke at the end that mostly goes over my students' heads.

I eventually discovered that the the clip is from an IMAX movie called "Straight Up: Helicopters In Action." It was produced in 2002 by SK Films for the Smithsonian National Air and Space Museum, and apparently aired as a cable TV broadcast by INHD, which later came to be called MOJO HD. I also came across a comment that it had appeared on Discovery HD.

Cross-posted to Teaching Is . . .

The Electromagnetic Spectrum

A couple of years ago, when my team of physics teachers started building instruction around the topic of electromagnetic radiation, I began assembling a list of different common uses of EM radiation. This list would provide a basis of information to use in our written instruction, as well as suggest hands-on activities, demonstrations, and labs.

I focused on uses that high-school students would be familiar with; cellphones, wi-fi and bluetooth, radar guns used to clock car speeds, microwave ovens, various remote control devices, tanning lights. My school is a technical school, so students have familiarity with other uses and devices; arc-welding, dental x-rays, high-voltage power lines, baby monitors, visible light and color. By focusing on what students might be familiar with, I hoped to reveal both prior knowledge and prior misunderstandings and misconceptions. A teacher could build on the prior knowledge, but more importantly would be obliged to address the misconceptions.

The list became a full table of data, with over 30 entries. It has become an object of study in itself, an exercise in the literacy of reading data tables and extracting useful information to answer questions and solve problems. This is a form of literacy familiar to our technical students, who in their shops must learn to read technical manuals full of similar tables.

The full table is shown below:



As usual for me, the table was constructed as an Excel file, making it easy to add or change data. If you have access to Adobe Acrobat Pro, you could also edit the PDF version. Here are the links for both versions:

Excel file, with instructions
PDF file

A very helpful online calculator and table: https://rechneronline.de/spectrum/
Another online converter and source of information: https://www.translatorscafe.com/unit-converter/en/frequency-wavelength/

Cross-posted to Teaching Is . . .