Updated on: July 2, 2026
This page is a showcase of the word definitions and transformations that I use on Plankton Valhalla. It’s a living document that I’ll update as more terms appear in future essays.
I think it’s worthwhile to tinker with the tools at one’s disposal, and the tool I have is language. Plankton Valhalla is about the content of its essays as much as it is about the exploration of new or underrated ways to explain those ideas.
A language is a fluid, plastic tool of the mind. Its way of changing is slow and organic, without anyone deliberately driving it. At some point people look back and realize that their great-great-grandparents wrote in a funny way. But sometimes people make changes to language intentionally, with specific goals in mind. This happens a lot in science: “virus” used to mean “poison” long before it was employed to mean a “microscopic infection agent”, and “field” still has its own distinct meaning(s) outside of the concept used by physicists, like “magnetic field”.
I sometimes modify or tune words on this website, and (usually) it’s intentional. Most often I do what’s called semantic broadening and semantic narrowing, meaning that I deploy an existing word with a broader or narrower meaning than usual. In most cases I borrow them from great thinkers of the past and present, rather than inventing them myself. I believe that making those changes is necessary to un-muddle certain topics and to shed light on points easy to overlook.
Still, changing the meaning of words out of the blue can be confusing! Hopefully the following list of customized terms will help you keep track. I’m not insisting that everyone adopt these modifications, but I do believe they are better in the contexts I use them in.
Index
BAEB index ⇧
BAEB stands for “Boundaries are in the Eye of the Beholder”.
A “thing” is a part of the universe that you—that is, an observer—decide to consider differently from the rest. To understand the world, we draw boundaries and give the inside of those boundaries names: “Alice”, “dog”, “rock”, “drift”, “tomorrow”.
But those boundaries are arbitrary, a convenience for the observer and nothing else. They don’t exist in reality as we tend to assume. This is an important point, so the acronym BAEB comes up often on this site.
More on this in The Invention of Systems and Boundaries Are in the Eye of the Beholder. đź’
Computation index ⇧
Computation is the transformation of information from one form to another.
Like with “information” (see Information), the word “computing” has been appropriated by some physicists and philosophers to have a much broader meaning: to transform something with a well-defined process, whether it’s an electronic device or not, living or not. So they say that an ecosystem, or a quantum state, or a group of cells—in short, anything physical—“computes”.
The insight in this usage of the word is tremendous. It leads to a very deep understanding of reality, and I will write about it extensively. But using the word “computation” so loosely is counterproductive. It strongly implies, in the mind of the average person, something that is designed, intentional, and aimed at a specific goal. Of course, the scientists that use the term know that no intention is necessary for such processes, so they can get away with it. But when you try to explain their research to a layperson, saying that “the universe computes” is very confusing.
On Plankton Valhalla I dial back the breadth of the word’s meaning to be only the transformation of information, where the word “information” is itself much more limited than the way those scientists use it. More on this in Carving Nature at Your Joints. đź’
Control index ⇧
Control is a human-implemented recursive process designed to achieve a pre-established goal.
You can look at things this way: when you have a goal, you find yourself in a “wrong” version of the world in which that goal state is still not achieved. So you have to take steps to correct the state of the world until you find yourself in the “right” version of the world, the one where your goal is realized.
The key word here is “correct”: you can gradually get closer to the goal by observing in what ways the current state of the world is wrong, doing something to eliminate those errors, observing again, and so on until you have converged to the desired result.
No matter how easy or difficult or (un)planned this process is, no matter how little or long it takes, it is always a feedback loop: a series of steps involving observations and corrections based on those observations. In other words, you create a recursive loop (see Recursion) tailored so that you—if you did it right and with a bit of luck—achieve your purpose.
Whereas recursion is made, in general, of causal loops that “just happen”, control is causal loops that are created by someone. In other words, control is intelligently designed recursion.
The term “control” is originally an engineering term, but I find it useful to expand its use like this to better understand many phenomena around us. I explained the concept in Recursion, Tidy Stars, and Water Lilies. đź’
Difference index ⇧
A difference is a trait, property, or feature that can be distinguished from others.
This is the meaning of the word that is generally understood, no tricks or modifications here. However, I make it work a lot harder than usual. Beyond being a convenient term to distinguish two things in everyday speech, I believe that “differences” between things are a fundamental idea for the understanding of reality. The reason should be obvious: if a difference isn’t there, nothing will happen because of it—and if something happens, it was because of some differences.
Everything that exists and happens in reality is determined by the countless differences that make them up at all scales. See Differences, Contraptions, and A Ripple Universe for an introduction, and Toying with Ideas of Glass Circuits for more examples.
I treat “differences” as a parent category for “information” (see Information). In other words, all information is made of differences, but not all differences are information. đź’
Information index ⇧
Information is a difference that makes a difference.
Here I differ from the common use in physics when defining this word. Physicists use this term in an extremely broad sense, to mean roughly “the recognizable arrangement of things”. In that sense, even a photon and a black hole contain information. This runs counter to the intuitive meaning of the word (“something that informs (someone)”), and is unnecessarily confusing.
I shun that usage, and instead base my definition on Gregory Bateson’s idea that information is those “differences which make a difference” (see Difference). Particles, black holes, people and everything else in the universe is made of differences, but only a very small subset of those differences counts as what I call information.
So who or what do they make a difference for? For a purpose, and this in turn implies that information is always meaningful (see Purpose and Meaning). More on this in Purpose From First Principles and Carving Nature at Your Joints. đź’
Meaning index ⇧
The correlation between information and purpose is called meaning.
The word “meaning” is one of the vaguest and most ambiguous in existence. People seem sure they know what meaning is, but few seem to agree on a definition, or even be able to spell it out. I take a pragmatic approach for this: there can be no meaning without purpose (see Purpose).
Although information is “differences that make a difference” (see Information), meaning is which differences are made towards whatever purpose you have. In this sense, those differences have a correlation (i.e. are sides of the same coin) with your goals, thus they are meaningful. In this set of definitions, all information is meaningful, and any difference with meaning is information.
This definition is not as sharp as one might like—how does one measure this “correlation”?—but I think it’s much better than the others I’ve seen, and quite simple. I explain this in Carving Nature at Your Joints. đź’
Purpose & Goals index ⇧
Purpose is having a goal, and a goal is a particular system state that a human wants to achieve by avoiding all other states.
To get what you want, you first have to set it as a goal (even if only vaguely in your head), then plan how you’re going to get to it, then try to execute that plan. As stated in the Control entry, a goal is a version of the world you want to turn into reality.
(If you want something but don’t set it as a goal, you will probably never get it; you may call that a dream, but not a purpose.)
The execution of your plan toward a goal is always a recursive process (see Recursion), but of a special kind called “control”.
Also, note how the definition of “goal” parallels that of “Water Lily” (see Water Lily): a goal is a special kind of Water Lily—one intended and implemented by a human.
Read more on all this in Purpose From First Principles. đź’
Recursion index ⇧
Recursion is when some differences affect their own future changes.
Everything is part of a network of interactions between differences (see Difference): A interacts with B interacts with C and D, and so on forever. Often, loops close onto themselves, as in “A interacts with B interacts with A”. This can take a few steps or many, and there can be multiple such loops “feeding back” into themselves, changing what happens to the upstream differences.
This simple closing of the loops, and the seemingly innocent self-affecting that it causes, open up a new world of possibilities that would be impossible with only open chains of interactions: recursion allows for the growth and suppression of patterns, chaos, periodicity and stability, explosion and control (see Control)—basically everything that matters for the Universe as we know it.
Once again, my definition of this term differs somewhat from the mainstream one, and is more general. See more in Recursion, Tidy Stars, and Water Lilies. đź’
System index ⇧
A system is a set of differences that is treated as an active and interactive unit by an observer.
This is another of those very important, popular, and rather vague terms. Each discipline seems to be using “system” in its own way. My definition is one of the broadest, closest in meaning to that of General Systems Theory developed by Ludwig von Bertalanffy. Here, a system is not just a collection of things: it includes their networks of interactions and transformations. You can read more about it in The Invention of Systems.
Note that this definition is different from the one used by one of the greats of systems science, Donella Meadows. She wrote in Thinking in Systems, a Primer:
Is there anything that is not a system? Yes—a conglomeration without any particular interconnections or function. Sand scattered on a road by happenstance is not, itself, a system. You can add sand or take away sand and you still have just sand on the road. Arbitrarily add or take away football players, or pieces of your digestive system, and you quickly no longer have the same system.
In my definition of the word, all those things can be systems: boundaries are in the eye of the beholder (see BAEB). The examples she calls “system” are what I’d qualify as “complex” systems, i.e. a subcategory. I prefer my broader definition because it helps, among other things, to clarify the distinction between living and non-living things. đź’
Water Lily index ⇧
A Water Lily is the particular state, out of many possible, that a system tends toward as the result of recursion.
When a system (see System) experiences recursion (see Recursion), several non-random things can happen to it: it can stabilize itself, destroy itself, oscillate in a regular pattern, and other things and mixtures of all these. Exactly what will happen to the system due to recursion depends on the specific conditions and the structure of its interactions, but it can become something very specific (although it doesn’t have to). That “something” is what I call a Water Lily, capitalized.
I made up this term, because I needed it and no one else had given it a name. Almost everything around us is a Water Lily: that’s how disarmingly general this concept is. So, out of the infinitude of possible names I could have given it, I chose the name of one of my favorite examples: the white flowers that grow in many ponds around the world.
Note that in no way does this definition imply the presence of a human, or any other kind of intelligence or intent, or even a living process: Water Lilies, in general, just happen as a consequence of looping chains of interactions, and that’s it. In the extremely unusual case (on universal scales) in which a human being plans and intentionally forces a certain mode of recursion to achieve a given purpose, we call that forcing work “control” (see Purpose and Control), and its Water Lily is the goal.
This concept is introduced in Recursion, Tidy Stars, and Water Lilies. đź’
Notes
- Top image: A hundred anecdotes of animals pl 057 (1901), Percy J. Billinghurst.