The Lambda
For HOPE 2022, Autumn and I flew to New York City.
We landed after a long day of airports and bad coffee, found some of the best Chinese food I’ve had outside the West Coast, and then walked across Brooklyn to visit a synthesizer shop that turned out to be closed.
Back at the conference, DJ Spock (of Chaos Computer Club fame) was waiting for us while we were haphazardly exploring Brooklyn. His text messages were intensely German: polite, efficient, a subtle humor most Americans would miss. I don’t remember what my excuse was, but I wasn’t about to tell a CCC legend that I was busy getting impromptu ink. His patience that day is something I’ll always remember. Later he would offer to teach me how to use his CDJ-3000s, an offer I regret refusing to this very day.
After finding the synth shop closed, we walked past a tattoo shop. From the street we could hear the legendary NY Hardcore band Gorilla Biscuits’ “Start Today” playing inside. Their discography is already tattooed on my brain, it was fate.
I don’t remember discussing it much. Autumn has always been down for spontaneous tattoos. Before long we were sitting in chairs getting matching lambdas inked onto our ankles.
The placement was terrible.
The tattoo sits on the meaty part above the foot, a location that rubs against every sock and shoe. Healing it while spending three days walking around HOPE and volunteering was a spectacularly bad idea.
I regret nothing.
The lambda has become our sigil.
In some ways it always was mine.
I just didn’t know it yet.
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Most people my age first saw the symbol in Half-Life.
Long before I knew anything about functional programming, lambda calculus, or the history of mathematics, I knew that symbol meant something. It represented scientists, outsiders, strange experiments, hidden knowledge, and people working on things the rest of the world didn’t quite understand.
Years later I discovered it had been carrying much older meanings.
Lambda has appeared in everything from mathematics to queer history to hacker culture. It has a habit of becoming a symbol for people who exist slightly outside the mainstream. Not necessarily rebels. Not necessarily revolutionaries.
Just people who see the world through a different lens.
The ones who end up standing in the corner of the party explaining some niche obsession to the one other person who cares.
Honestly, those are usually my favorite people.
I love hearing someone rant about a special interest. Not a polished TED Talk version. The real version. The version where they forget to check whether you’re still following along because they’re too excited about medieval shipbuilding or train signaling systems or some obscure theorem.
Those conversations have probably shaped me more than any formal education ever did.
Including mathematics.
As a kid I had basically no interest in math. I was fine at it, but school managed to turn it into a sequence of worksheets and scores and deadlines. It felt like a subject you performed rather than explored.
Then adulthood happened.
Nobody was grading me anymore.
Suddenly mathematics became fascinating.
I could wander into topology because it sounded weird. I could spend an evening reading about combinatorics for no practical reason whatsoever. I could fall down category theory rabbit holes at 1 AM and emerge several hours later convinced reality was secretly made out of arrows.
The funny thing is that math started feeling a lot like listening to people talk about their special interests.
You find someone who is deeply obsessed with a thing.
You let them explain why it matters.
And if you’re lucky, for a moment you get to see the world through their eyes.
The ones who build strange projects because they can’t help themselves.
The ones worth listening to.
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My favorite category theory story happened when I worked at Riot.
We had a community code night and I ended up chatting with a guy around my age. He commented on my Clojure shirt. Why yes, fashion is my passion. It’s purple and usually doesn’t have crumbs on it.
We got talking and somehow the conversation drifted into the mathematical rabbit holes I had recently discovered: topology, combinatorics, category theory. At the time I was deep in the honeymoon phase where every new concept feels like you’ve uncovered a secret wing of reality.
Category theory in particular was blowing my mind.
I had spent the previous week consuming YouTube lectures and enthusiastically explaining functors to anyone unfortunate enough to make eye contact.
So naturally I told him he should check it out.
“Category theory is incredible,” I said. “You should really look into it.”
He smiled.
“Yeah, definitely worth checking out.”
We exchanged contact information and I asked what he did.
“Mathematician.”
“Oh wow. What’s your focus?”
A pause.
“Category theory.”
There are few experiences more humbling than passionately recommending a subject to someone who has dedicated their life to advancing it.
To his credit, he was extremely polite about the whole thing.
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The symbol’s most famous technical appearance comes from lambda calculus.
In the 1930s, mathematician and logician Alonzo Church was trying to answer a deceptively simple question:
What is computation?
Not computers. Not software.
Computation itself.
His answer was astonishingly minimal.
Take a symbol.
Give it a variable.
Give it a body.
Now you have a function.
A machine for transforming one thing into another.
Church chose the Greek letter λ to mark these function abstractions. Historians still debate exactly why. One common explanation is that it evolved from earlier notation and gradually became simplified into the Greek letter.
The reason almost doesn’t matter anymore.
The symbol escaped.
Today λ means “a function” in the same way a heart means love or a skull means danger. The original explanation has become less important than the meaning people attach to it.
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What I love about lambda calculus is that it starts with almost nothing.
A lambda expression is just a rule.
A transformation.
An input becomes an output.
That’s it.
Yet from that tiny foundation you can build astonishing complexity. Entire programming languages. Compilers. Operating systems. Modern software infrastructure.
A universe hidden inside a single symbol.
There’s something almost mystical about that.
Not supernatural.
Just the kind of mystery that appears whenever simple rules create unexpectedly rich worlds.
The same feeling you get watching Conway’s Game of Life produce patterns that seem alive.
The same feeling you get staring at a circuit diagram, a cellular automaton, a strange mathematical proof, or a city viewed from an airplane at night.
Complexity emerging from simplicity.
Order emerging from symbols.
Meaning emerging from marks on a page.
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The occult world has a concept called a sigil: a symbol that accumulates meaning through use.
Whether you believe anything supernatural is happening is beside the point.
Humans are meaning-making machines.
We carry symbols with us.
We invest them with stories.
Eventually they become shorthand for entire identities.
The lambda works that way for me.
It represents curiosity.
It represents weirdness.
It represents the kind of person who learns things simply because they are interesting.
The kind of person who can accidentally spend three hours learning how Soviet spacecraft worked or why a particular compiler optimization exists.
The kind of person who knows what a monad is and cannot be trusted to explain it briefly.
Especially that last one.
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These days, when I see a lambda sticker on a laptop, I have a pretty good idea who I’m dealing with.
Maybe they’re a Lisp programmer.
Maybe they’re into Haskell.
Maybe they’re a mathematician.
Maybe they’re just another weirdo who found their tribe through computers.
Whatever the reason, it’s a recognizable signal.
A pirate flag.
A quiet declaration that normal was never really the plan.
And if you’re wondering how lambda calculus eventually led to Lisp, functional programming, strange programming languages, and several decades of computer scientists enthusiastically reinventing the same ideas over and over again—
Well.
That’s a story for another day.