Simon DeDeo Profile picture
Faculty, Carnegie Mellon University & the Santa Fe Institute. Runs the Laboratory for Social Minds.
A. S. ☀️💧Leon-Gerard Vandenberg 🇨🇦🇦🇺🇳🇱 Profile picture Joshua S. Lieu Profile picture Robi Profile picture Potato of Reason Profile picture 5 added to My Authors
7 Apr
.@ycombinator as the apex predator of gifted programs, middle-class testing culture, and "the Stanford Marshmallow Prison Experiment". Pretty killer lede in @ben_r_hoffman's response to Paul Graham's "lessons to unlearn".…
Related: @dellsystem's Abolish Silicon Valley, which is in part a bildungsroman about escaping this "final boss" of the meritocracy.
Ben puts together a lot of pieces of the Y Combinator story, which appears to narcissism and splitting on a billion-dollar scale. Gatekeepers like Altman and Graham impose arbitrary, rapid fire demands on applicants—and interpret obedience to their whims as excellence.
Read 8 tweets
6 Apr
Related to something I learned from a @gwern essay. When you find a chemical that improves performance, you have to ask—why doesn't my body make it already? Evolution is not a moron. Caffeine, nicotine, modafinal, LSD. You can't live your life on them, "or we already would."
Always possible that the only way to synthesize the chemical is through some intermediate and highly toxic process. But evolution is pretty handy with proteins: "it can fold a crane".
Right—"hey, we built a society that involves poisoning yourself". That reminds me of the @PaulSkallas / Neal Stephenson / Kim Stanley Robinson point: we'll never live in space, space sucks and wants you to die.
Read 43 tweets
5 Apr
Today in cascading discoveries. I cleaned out the MacBook Pro and, because I live on the edge, replaced the thermal paste on the CPU/GPU. All of a sudden, the battery started draining while the system was plugged in. @trishankkarthik was right! I ruined something. BUT...
I thought through the problem a bit. Why would improving heat management lead the battery to drain faster? One thing I noticed is that I was now running my CPU at 3.5 GHz rather than 3 GHz...
Which is presumably because the thermal management is better and the system doesn't have to throttle for heat as much. But this also means that more power is draining. I open the panel where the power strip is, and notice the fault light is on...
Read 7 tweets
25 Mar
So many cognitive science teachable moments in this utterly fascinating and self-aware account of online sex work by @Aella_Girl. e.g., below—“Theory-theory” vs “simulation-theory”. AG will be on @breakth3rules this evening with @giantgio.…
How many layers of recursive thinking are going on when a sex worker who talks about feminism, IQ, and manipulating people online agrees to this debate format? Poll below...
@Aella_Girl arguing the anti-feminist position should be taken at level...
Read 19 tweets
25 Mar
Two ways of thinking about mathematics: as a computational process (Hilbert, Turing) unfolding in time, and as a static object (e.g., our epistemic networks in “explosive proofs” paper)...
The latter style has (in my memory) greater prestige. Consider the definitions of open, closed, and compact sets in point set topology—often in a “static” form that asserts the existence or non-existence of objects with properties, rather than methods for constructing them.
The idea that mathematical claims are process claims, rather than property claims, still feels alien to me. Even the unfolding of a proof feels “at one remove” from the truth being established.
Read 16 tweets
24 Mar
Stunning chart via @PaulSkallas. Current student loan debt to USG *alone* is $1.4 trillion. Total size of US mortgage market is only $10 trillion.

What is the *true* value of the college degree? What happens if employers stop valuing it? What happens if students stop paying?
This, to me, is crazy. IMO college education is extraordinarily misunderstood and mispriced. Much of it is “bubble” value—informally, “the hardest thing about Harvard is getting in”—that could decline precipitously.
e.g., not hard to imagine curriculum and staffing changes that meant CS departments just stopped teaching students how to code. (Something similar has already happened in many classics programs: you don’t need to learn a classical language to get a degree in classics.)
Read 30 tweets
23 Mar
Running financial time-series models all morning. This should be required training in statistics and philosophy of rationality.

Bias pours through every gap—e.g., in your choice of when you give up on a particular method, when you CTRL-C an expensive calculation, etc. Just wild.
If you're good, you can see it in action, because you have two things happening at the same time: (1) your intuition about how good a new method is, (2) the actual metrics that you can't hack post-hoc.
But of course, that's only the intuition that you know is going wrong. The way you're setting up (2), meaning, your intuition that (2) is a legit and solid metric that you're not motivated-reasoning into the black, is completely unknowable.
Read 9 tweets
20 Feb
Elizabeth Sandifer has a harsh—but not on-the-face incorrect—burn for Yarvin’s politics and political theory. If “code is law”, and Urbit is CY’s tour de force— I’ve come to understand Urbit as a software engineering train-wreck...
...which is not to say Urbit doesn’t have a use case—it does. Somewhat like taking Sanskrit for your college language requirement, it’s a costly signal of, well, something. Affection for John Locke’s theory of value?
I certainly have seen lots of interesting people who have gotten in to the system. For all the retconning, it’s clearly a political project, but one that’s captured the imagination of a weird and diverse group.
Read 6 tweets
13 Feb
What's the earliest you could have predicted that Python would be one of the top five programming languages? (Round to nearest year.)
I’m going to say 1995, but hear me out. (1) We already knew that attacking problems with computers, in a sort of ad hoc fashion, was going to be a big deal. *All* problems had a computational side, not just a special class.
(2) We knew that domain knowledge mattered—that the more the “ordinary” practitioner had direct access, the greater the payoff. No separate “computer group”.
Read 5 tweets
13 Feb
The best line on the rationalists, said to me once: these are the people who read the New York Times and took it seriously. What follows next is the response to that disappointment...
Effective Altruism is the most obvious (the Times says first world philanthropy will save the third, and yet it hasn’t happened yet); multiple different diagnoses for Neoreaction, I think.
A lot of people want to trace things back to SV culture, but this seems wrong. E.g., early Paul Graham essays, which are mostly about how to make money on startups, or inside baseball about code.
Read 15 tweets
6 Feb
Thoughts on tails and Hayekian (neo) liberal economics. The standard story is that markets “learn”—absorbing trades and propagating the implicit information by setting prices. It’s sufficiently intelligent to bring me tea from Japan. But tails *can’t* be learned... Image
They don’t occur often enough to train the reenforcement algorithm that the price system runs. When they do, their surface logic is unrepeatable (GameStop, really?)
Tails can, however, be reasoned about. We can think about what would be out of scope, even if we can’t anticipate its details. We can ask if this or that profit is on some sense “unreasonable”, emphasis on reason, not inference.
Read 14 tweets
18 Jan
Someone tosses a coin ten times; it comes up heads every time. What's the probability it comes up heads on the next toss? (Pretty darn high—part of @nntaleb's work is unprogramming you from your high-school rules of thumb.) Now consider the (related) Gambler's fallacy...
In this case, it's a theory about compensation: the worse one's luck is, the more likely it is to see a reversal. On the surface, it's irrational. The more bad luck you have, the more you accumulate evidence that the system is rigged.
But there's also an anthropic component. If the luck is bad enough, it starts to become inconsistent with your survival. You've accumulated evidence for correlations in the environment, but these correlations (may be) inconsistent with (people like you) being in this environment.
Read 18 tweets
18 Jan
Say we gain complete control over genetics—we can code development like Python. After 10,000 years, which is the most likely outcome of our decision-making?
Can’t believe the elimination of men and permanent sexual immaturity/liminal stage are getting so few votes.
I don’t think speciation events are likely. Silicon software has been converging on near-total comparability for decades.
Read 5 tweets
30 Dec 20
2021 predictions (🧵)
Student loans will (finally) be understood as a bubble on a par with the housing market in 2008.
Some of the fallout will be temporarily explained away by COVID, but many universities below the billion-dollar endowment mark (and some above) will find themselves short.
Read 22 tweets
29 Dec 20
You guys told me julia was cool, but it turns out that it indexes arrays beginning with one? I'm sort of not joking—what possible justification is there to violate the near-universal standard?
This is very Bluebeard's Castle. What else is in the cupboard, "Julia"?
One-indexing considered harmful.…
Read 10 tweets
19 Dec 20
Let’s check in, as @PaulSkallas says, with the DMs. Five books after @nntaleb 🧵
I’ll take the Taleb-namecheck seriously. Black Swan is an amazing book, which merges life history, fiction, philosophy, and (by the by) plenty of complex mathematics. So this list will be a little weird.
First: the Dialogues. They should be read as dramatic pieces. “What kind of mind do I see?” Every kind of foolishness and grace is on display. Socrates himself grows and develops over time. Translation mostly irrelevant.
Read 23 tweets
15 Dec 20
The truth appears to be the exact opposite. What Paul calls “low-level” employees seem to understand the lines very well, while middle (and sometimes top) management blurs them to protect revenue sources.…
Quite striking to see everyone jumping on to (1) agree with Paul, and (2) talk about how dumb the content moderators are, when the New Yorker article basically shows all of this to be total fantasy. For example...
It’s not that content moderators can’t understand context—rather, they are explicitly instructed by management to ignore it. Image
Read 13 tweets
2 Dec 20
One way to find failing institutions is to look for the ones that use, and endlessly debate, metrics.

Healthy systems have notions of success that evolve on the same timescales as the tasks themselves. (🧵)
The graduate admissions that I’ve seen is pretty healthy. The endless debates on whether or not to use GRE seem beside the point: discussions on who to admit, in my experience, end up as really interesting conversations about science itself.
Faculty hiring is more complicated, and it’s easier for people to look at metrics. Usually, how many papers in “top” journals; sometimes divided by the number of years the person’s been out.
Read 17 tweets
1 Dec 20
The whole thing, completely collapsed. A major scientific installation in Puerto Rico.
Much of Arecibo’s greatest science (including a Nobel for gravitational waves, the discovery of Mercury’s 3:2 spin-orbit resonance, etc) was a long time ago. But there was still great science going (pulsar astronomy, e.g.), and it was transitioning to a teaching tool.
In my opinion, the collapse of the dish—the total destruction of one of Puerto Rico’s jewels—is a massive scandal and should be covered by science journalists.
Read 16 tweets
16 Nov 20
Have been waiting for the @PaulSkallas video game essay, and now it’s out on the substack. A few thoughts...…
First, obviously, he’s completely right. It’s a devastating take on something that’s right in front of your eyes. I stopped playing games at 13 (except for a bleak time in grad school) so it doesn’t hit me in the gut, but perhaps it does for slightly younger people.
He’s right, unfortunately, about “indie” games. I’ve played a few out of curiosity, and there’s not much there. Occasionally something high concept, but nothing that grabs you.
Read 41 tweets
8 Nov 20
On Bayesianism, the Many Worlds Interpretation, and personal identity.

Some thoughts worked out in a letter to a friend, which is the kind of thing you do when off Twitter for a glorious week. (🧵)
“Chance is ignorance”—the Bayesian story; all probabilities represent states of mind, not states of the world. One *could* put (some) chances “in the world”, but let’s take Occam’s Razor seriously...
That the probability of a fair coin coming up heads is 50% simply means that marginalizing (tracing, as the physicists say) over the hidden facts leaves you, nearly, maximally ignorant of the outcome.
Read 40 tweets