Why I Miss My Physics Class: What It Taught Me About Letting Kids Figure Things Out
Last Tuesday, my seventh grader asked me why helium balloons float but a balloon filled with air sinks. I opened my mouth to give a quick answer, then stopped. I was seventeen again, standing at the back of Mr. Alvarez’s physics classroom, watching him drop a feather and a hammer inside a long glass tube. He flipped the tube over and they fell at exactly the same speed. I remember the quiet murmur of the class, and how someone said, “That’s not right.” And Mr. Alvarez just smiled and said, “Maybe gravity doesn’t care what you think.”
I think I miss my physics class.
I didn’t realize it until that moment. I’ve been a parent for twelve years and a part-time substitute teacher for three. Somewhere along the way, I convinced myself that physics was just a subject I used to know—a collection of formulas and definitions I could look up if I had to help with homework. But standing there in my kitchen, with my son’s lunchbox still open and the dog barking at the mail carrier, I felt a strange ache. It wasn’t nostalgia for a textbook. It was something like missing an old friend who never gave you a straight answer.
In Mr. Alvarez’s class, we never got neat answers. We got questions and objects. We pushed carts up ramps, timed marbles rolling across the floor, and argued about whether a falling object would land before or after a dropped one. He made us draw diagrams, then cross them out, then redraw them. One day he put a ping-pong ball on top of a liter of soda and asked us to predict what would happen when the bottle was opened. Most of us guessed it would just float or maybe spin. When the ball shot toward the ceiling, we all jumped. Then he asked us to explain why. We had to work through it together, half wrong, half right, learning to be okay with not knowing.
That feeling—the discomfort and the excitement of not knowing—is what I miss. And it’s exactly what I tend to avoid now, both as a parent and as a sub. When my kids ask me a question, my first instinct is to answer it quickly, correctly, and efficiently. I want to be the one who knows. I suspect most of us do. But I’ve noticed that my seventh grader doesn’t really want an answer when he asks those kinds of questions. He wants to think about it. He wants to try things. He wants to be the one who figures it out.
So instead of explaining buoyancy, I said, “Let’s find out.”
We grabbed a can of regular soda and a can of diet soda from the fridge and filled the sink with water. I asked him to predict which one would float. He looked at me like I had three heads. “They’re the same size,” he said. “They’ll both float, obviously.”
We dropped them in. The diet can floated. The regular can sank. He stared at the sink for a long moment, then muttered, “That makes no sense.”
I bit my tongue. I didn’t explain density or the small difference in sweetener content. I just said, “Why do you think?”
He picked up the regular can, felt its weight, then picked up the diet can. “This one’s lighter,” he said slowly. “But they look the same. So something inside must be different.” He turned to me, eyes bright. “Can we weigh them?”
We used the kitchen scale. The regular can was about 30 grams heavier. He set it down, looked back at the sink, and said, “So it’s not about how big it is. It’s about how heavy it is for its size.” That was his own version of density, discovered over a sink full of dishwater and two cans of soda.
That moment didn’t happen because I’m a great parent or a patient teacher. It happened because I remembered that being confused is how learning actually starts. In Mr. Alvarez’s class, the best lessons were the ones where I walked out with more questions than I had when I came in. The formulas I memorized are long gone. But the feeling of figuring out something that didn’t make sense—that has stayed with me.
For parents and teachers, I think the practical lesson is pretty simple: resist the urge to become the answer machine. When a child asks “why,” try pausing. Ask them what they think first. Even if their guess is wrong, let it stand for a minute. Let them see that being wrong is a step, not a failure. With my son, I could have just told him why the diet can floats. He would have nodded, maybe repeated it, and then moved on. Instead, he got to feel the weight of a can in his hand, test a prediction, and be genuinely surprised.
You don’t need a lab or expensive equipment to do this at home. Everyday things work well. A sealed water bottle and a plastic bottle with holes in the bottom. A fork and a spoon dropped from the same height. A toy car rolling across a floor made of carpet, then tile. The key isn’t the experiment itself. It’s the space you leave for the child to observe, guess, and revise.
As a substitute teacher, I’ve also tried this in classrooms. When students ask a tricky question, I sometimes say, “I have an idea, but I’m curious what you think.” Or I intentionally make a small mistake on the board and see if anyone catches it. That usually gets more engagement than a perfect explanation. It turns learning into a shared hunt instead of a lecture.
The other thing I miss about physics is that it didn’t pretend to have easy answers. It was comfortable with uncertainty, with “it depends,” with “we’ll test that tomorrow.” That’s a strange thing for a subject to teach, but in many ways it’s more useful than the content itself. I’ve been trying to be okay with saying “I don’t know” in front of my kids. It feels uncomfortable at first. But the reward is that sometimes they take over the thinking, and I get to watch.
Last night, my son was still talking about the soda cans. He hadn’t taken any notes. He didn’t write down the word “density.” But at dinner he asked his younger sister, “Do you think an egg floats in saltwater?” They spent the next ten minutes dropping a boiled egg into jars of tap water and saltwater, arguing about the results. I didn’t say anything. I just stood at the stove, stirring the pasta, and let them be confused together.
I think I miss my physics class, but I’m also starting to realize that I never really left it. It’s just taken a different form: a kitchen sink, a can of soda, a kid who wants to test an idea. I haven’t signed up for a night course. I haven’t bought a telescope. But I did add a small pendulum to my shopping cart last weekend, and I hung it in the hallway. My son asked why. I said, “I think it looks interesting.” He watched it swing for a moment and said, “Okay.” Then later, I saw him give it a push and time it with his phone.
He won’t remember much about that afternoon, probably. But he might remember the part where he got to be the one who figured it out. That’s what I’m hoping for. That’s what Mr. Alvarez did for me, and I barely remember a single formula. I just remember that I was allowed to be wrong, and then try again.
The dishwater is cold and the cans are still sitting on the counter. But that’s okay. We’re not finished yet.
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