Activation Energy is a good model for a lot of things

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Activation Energy is a good model for a lot of things<br>(shortpost)

Duncan Sabien<br>Aug 03, 2026

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I hate every graph I found on Google for “activation energy” so our thumbnail for this essay is just gonna be

Heat some paper to 300ºF (150ºC) and mostly what happens is you have some hot paper.<br>Heat some paper to 500ºF (260ºC) and what you have is a fire. You can use that fire to start other fires, and there’s a self-sustaining thing happening that will go on until all of the locally available fuel is consumed.

If you’re trying to push a table or dresser across a floor, and it takes fifty pounds of force to get it to start moving, it probably only takes forty or thirty pounds of force to keep it moving. Static friction is almost always greater than kinetic friction.

Most neurons in your brain are connected to something like a thousand other neurons. Those other neurons are firing, and firing, and firing, and at some point enough of them fire in close-enough proximity, and that causes this neuron to fire. It’s more complicated than this very crude model, but if 10 of the neurons this neuron is “listening to” say “go,” usually nothing happens. If 700 of them say “go,” something does!

Why am I writing this essay? Definitely not because an objective assessment of the ~80-or-so partially written essays I have in my stack reveals that this one is the highest product of effort and impact.<br>Nope, I’m putting this particular one out because a few musings on the concept of activation energy got me sitting down at my desk and typing. The required initial investment in the essays Making the Other Monkeys Feel Bad, and You Are The Deer In The Subway, and Defense Against the Dark Arts (which is like 93% finished already, even) is just … a lot higher. The initial investment for this one was low, partially because it’s short and simple and partially because my shower thoughts were already going there.

How do you make a certain kind of friendship last?<br>In the summer of I-think-it-was-2006, Steph and Eric and Rebecca and I ended up hanging out every single day for something like five straight weeks, and it was in part because, as we headed home each night, we just naturally found ourselves asking “so, when are we starting tomorrow?” Each hangout begat the next hangout, which begat the hangout after.<br>In the frame of activation energy, you could either view this as “we made the activation energy for each additional day really low, somehow” or as “yeah, once we activated Being The Type Of Friends Who Hang Out, the energy it took to sustain that was pretty low.”<br>There’s momentum coming out of basically anything, and you either sustain it, or it fades, and typically starting over from scratch requires much more effort than keeping it going.

How much energy does it take for your romantic partner to broach a difficult conversation with you? How hard is it, for them to arrange the preconditions for that sort of conversation to happen at all (let alone to arrange the preconditions for it to go well)?<br>Can you do anything to lower that activation energy? Presumably, you want to, because presumably you don’t want your partner just … sitting on a bunch of unmentioned resentments that build and build and build and build…

Putting the cookies on a high shelf is meant to be an activation energy intervention—it’s meant to make it harder to access the cookies, so that you’re less likely to do so.<br>Putting your exercise bike in your living room, where you see it every day, is meant to be an activation energy intervention, to reduce how much oomph it takes to get you to exercise.<br>But I think a lot more things are accurately modeled by activation energy than just the obvious ones that everybody already talks about. There’s a way that you could squint, and think about pretty much everything in terms of activation energy.<br>(You could model sex as happening when both partners exceed the activation energy threshold, and not happening when only one does.)<br>(I don’t recommend permanently shifting your worldview in that way, and fusing activation-energy-goggles to your face forever, but I do sort of recommend spending a whole week keeping activation energy at the front of your mind, and letting your brain sink into the Tetris effect, and seeing it everywhere, from how much activation energy it takes to get you to open your mouth and talk, to how much activation energy it takes to cause the world to do something useful about the race to lethal superintelligence.)

Where does your activation energy come from?<br>“Introverts” get more of it from quiet time, and “extroverts” from other monkeys. Most people have more of it if they’ve eaten in the last few hours than if they haven’t. Some people get disproportionately large AE from negative stuff—they’re highly motivated to avoid bad outcomes. Others find that the big boosts come from positive, “toward” energy,...