Constructing Physical Science

Adam Johnston

course notes

considering energy

Here's my rant about energy and how we'd typically treat it in an introductory physics class. We might say something about "energy" and say that it has something to do with "work," and then we'll turn around and define "work" as having to do something with "energy." This is circular and non-helpful.…

popping popcorn

In a typical class or Friday night, I'll pop popcorn and wonder: What happens to the stuff of the popcorn kernel as it is transformed into the morsel of popped corn that I can eat? Those two "states" of the corn are really different. One I can eat easily, the other seems impossible and would break m…

a walk

I spent part of the early evening with some science teaching students walking up through the trees to the former shoreline of Lake Bonneville. Their task was to make observations of phenomena they could use to center science learning around. I took photos of some of what caught my attention.…

motion analysis: freefall

Adam went to the trouble of throwing a ball up into the air in his office. The ball not only went up; it came back down. Here's video of the event: (It's also available on YouTube, here.) You can study this motion in a variety of ways. In another video example, I suggest that you analyze the frames …

noticings and wonderings of scientists blowing bubbles

I dropped by the offices of scientists around my building here at Weber State University and asked them to blow bubbles and tell me about the things they notice and wonder. At the same time, I recorded video of these episodes on my phone. Here’s a quick 10-minute compilation of the things they did, …

hair’s width

The width of a human hair is pretty small, so you probably don’t have a good way of measuring it directly. However, you can use other methods, and these are the same as how you might study materials and the arrangement of molecules that you can’t see directly. We use the diffraction of light around …

drinking bird

I often host a lab where we study the Drinking Bird in its native habitat. But, in case you don't have a chance to be in my lab and you don't have your own drinking bird, here's some video you can analyze. The bird goes through two of its cycles in this clip, and I repeat those cycles at high speed …

liquid motion

What makes up matter? We can't see it directly, but observing some details might help us imagine what's going on at a deeper level. https://youtu.be/pAvsUTlmncM I have two glass bottles of water that I drop red dye into. All the water came out of my faucet, but the two bottles behave differently. Wh…

sound tubes

Different musical instruments work because they play the note you want to hear. This seems obvious, but it's no small thing to make something play exactly the right note, and leave out all of the other noise. How do they do this? Instruments are made from lots of different stuffs and geometries. Som…

upward liquids

A lot of people don't believe me when I tell them this, but I truly don't understand how water crawls up a paper towel or string or piece of cloth. How does it get the energy to do this when it's just sitting there; and the towel is also seemingly passive in the whole affair? I'm a physicist and I w…

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