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 my teeth. So what happens to that stuff as it’s heated? In particular, does the stuff that’s there stay the same or does it change? I know that it’s different in some way, but how do I model the matter of this popcorn and where it goes (or stays)?

There are probably lots of great models and lots of great ways to think about this. As you do, you could use your model to predict if the kernel changes its mass as it is popped, or does it stay the same? And, if it does change, does it get more or less massive? And, regardless of what happens, what does that tell us? How do our models help explain what’s going on as popcorn is popped?

I documented this mini-investigation in a video:

I’m adding some space here so that there aren’t any spoilers. Below are a few screen grabs of the video that capture some key moments in my science and acting career.

Pointing out the kernel. It’s hard to see, because it’s small. That’s actually part of the challenge.

I thought I could weigh a single kernel to compare to after it popped. It’s really hopeless because the kernel is too small, and …

…wouldn’t it be a better idea anyway to have a bunch of kernels, in case some don’t pop or something else weird happens. Plus, this is easier to weigh.

The bucket by itself was 95 grams, but with the added kernels the total mass was 166 grams. So that means that the kernels by themselves were 71 grams, but it’s easy to just keep track of the popcorn in the bucket since that stays the same.

Live action! Pouring kernels into the air popper! (It’s probably important that I was using an air popper without any butter or oil.)

Popcorn! In the video, I speed up this part of the footage, which is kind of fun and convenient.

[Drumroll, suspense, etc.]

Final massing of the popped popcorn with the bucket. What happened?

A summary of our data.

Huh.

That’s a loss of a few grams. Doesn’t seem like much, but it’s pretty substantial in comparison to what we started with–about a 10% loss of stuff. So where did that go? It could be mistake, but this was monitored and it’s repeatable. We also talked about it being air in the kernels, or some kind of chemical reaction, or some loss of liquid water that could have been in the kernels. Or maybe something else.

There are a few things that could be helpful to know. For example, the density of air is something like 0.001 gram per cubic centimeter; and the density of water is about 1 gram per cubic centimeter. That helps us think about how much stuff we could lose of either of these and what we might expect that to look like.

This quick investigation was done with an air popper, but when I pop popcorn at home I do it over a stove and have a glass lid. This way I can see a little bit more of what’s going on. So, the other thing I could contribute is what it looks like when I pop popcorn. I recorded the video and put it on the internet, because I figured that was what the world needed:

Here’s few highlights from the video, just for posterity: