The concepts of force, matter, and energy get mixed together and confounded. For example, it’s easy to say that forces, matter, and energy are all in the following photos. But these are all distinct from one another, even though they’re related. Where and how do you see forces, matter, and energy in these?

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Generally, I don’t like to define words up front. In this case, I just want us to start painting edges around these terms, not so much to define them as to make sure we recognize that they’re all playing in different but complementary fields.

A force is an action. It’s the push or pull between two objects. These always come in pairs exerted between two objects, one on the other and the other on the one.

Matter is stuff. You can put it a container and close the lid. Sometimes that container will need to be really, really big, but if it’s a thing or a collection of things and takes up space, you have some matter.

Energy — oh, energy. This, to me, is the hardest because it feels so obvious but also isn’t either a piece of something nor something I push against. It’s a property of matter that describes what the stuff is doing or what it could do. Energy is transferred or changed in matter by forces (even though not all forces do this).

Clear? No, I didn’t think so. For now, let’s be content but confused with the idea that these three categories are completely different, like Doritos are different from love is different from sound. You know that one might have relevance to the other, but you can’t compare Doritos to love to sound. They aren’t even on the same plane.