Constructing Physical Science

Adam Johnston

#randomactofscience

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…

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…

static cat

I like to tell students that cats love to do physics. Seldom do I actually get a chance to show them, however. Thank goodness I can make videos so that I don't have to bring Gus to class with me. Here's some work we were doing together to investigate how balloons and cats stick together. https://www…

hummingbirds in slow motion

I don't have much to say about this except I really enjoy watching hummingbirds. Even in slow motion they're still really fast. I like the way that they turn their wings and use their tails to maneuver, but I'm especially fascinated with how still their heads are while everything else is moving: htt…

balancing acts

If you see me in front of an in-person class and I have a meter-stick, you'll often witness me trying to balance it in various ways. The most impressive and kind of magical way to balance a ruler, stick, baseball bat, etc., is using this trick of sliding your fingers towards one another. They natura…

ice melting

On hot summer days you might really enjoy a glass with ice, just because you like a cold drink. But have you watched the ice in your glass up close? This glass of ice water shows that the ice floats at the top. You probably see this all the time. I like investigations just watching ice melt. By taki…

sun circles

It was a nice morning, and I thought it would be a good choice for me to sit in my backyard and read a book. But it's easy for me to get distracted, and soon I was really interested in a spot of light that was on my chair: Reading outside, I saw this spot of light on my chair.(For more information a…

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