Back in March, I wrote about centrifugal and centripetal forces in reading: books that suck you in, and books that spin you out:

Little bits and pieces have come back to me that I want to collect here.

First, my friend Matt Thomas, who planted the idea in my head in the first place, told me he thinks about what kind of force a piece wants to have when he’s creating it. He asks himself, “Do I want to suck people in or spin people out?”

Matt also points out that these terms — centripetal and centrifugal — are helpful to keep in mind when consuming media of all kinds. There’s media designed to suck you in (social media, slot machines, etc.) and there’s media designed to spin you out (the “spin,” or propaganda, of public relations, etc.).

William James thought we had centrifugal and centripetal forces inside of us:

He identified two human tendencies, the centrifugal, or “expansive embracing tendency,” and the centripetal, inward-moving or “defensive.” He noted that these tendencies represented two different modes of self-assertion, the expansive representing the sympathetic mode, the centripetal the self-sufficing mode, and he wondered, inconclusively, if the two together might add up to self-respect.

In The Dialogic Imagination, M.M. Bakhtin used the terms to describe what happens in the life of a language. Centripetal forces unify and centralize a language, and centrifugal forces push it apart and towards chaos. He said “every utterance” has both these suck and spin forces, and every utterance is a “contradiction-ridden” and “tension-filled” combination of these “two embattled tendencies.”

https://www.youtube.com/watch?v=rtFnki476cU

What has blown my mind the most while investigating these terms is that in physics, centripetal force is a real force, but centrifugal force is an “apparent” force:

“The difference between centripetal and centrifugal force has to do with different ‘frames of reference,’ that is, different viewpoints from which you measure something,” said Andrew A. Ganse, a research physicist at the University of Washington. “Centripetal force and centrifugal force are really the exact same force, just in opposite directions because they’re experienced from different frames of reference.”

If you are observing a rotating system from the outside, you see an inward centripetal force acting to constrain the rotating body to a circular path. However, if you are part of the rotating system, you experience an apparent centrifugal force pushing you away from the center of the circle, even though what you are actually feeling is the inward centripetal force that is keeping you from literally going off on a tangent.

As far as I understand this, what we call centrifugal force is actually just inertia working against centripetal force.

So, for example, if you’re driving fast and you steer into a tight curve, the force you’re feeling pushing you outwards is really just the inertia of your body still moving in the direction you were going in before you took the curve.

(Newton’s First Law is the most important one a creative person can memorize: “a body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force.”)

Nerds and science teachers like to harp on this misunderstanding, but I believe misunderstanding can be its own creative act, and using the terms out of their context can lead us to new understandings. I like to think about how much poorer my intellectual life would be if the thinkers above didn’t steal these terms and export them to new places.

I hope this post has spun you out nicely.