Astral Codex Ten Podcast

The annual prediction market conference was earlier this month. This was the year prediction markets went from an obscure hobby to a multi-billion dollar industry; from semi-illegal to having the President's son as an advisor. I can't remember if anyone talked about any of that. It didn't even register. All eyes were on the AI superforecasters.
I met an AI superforecaster startup founder who told me his AI had turned $35 into $2 million on Kalshi over seven months. I met another who said they were beating the stock market by 25% with a market-neutral portfolio - of course this could be luck, but they'd beaten Kalshi and Polymarket by similar margins.
In fact, I believe all of these people. The extending-lines-on-graphs community has long predicted that AIs would beat the best human forecasters sometime in 2026 - 2027. What did you expect the bots-finally-beat-humans-at-predicting-the-future moment to look like? Vibes? Papers? Essays? In retrospect, sure: it will look like AIs making crazy profits on prediction markets and beating the stock market by some comfortable amount.
https://www.astralcodexten.com/p/the-ai-superforecasters-are-here

I.
Having kids has given me new appreciation for old poetry. The first time I read Song of Hiawatha, I skimmed over the part in Book 3 where Hiawatha first meets his father Mudjekeewis:
Filled with joy was Mudjekeewis
When he looked on Hiawatha,
Saw his youth rise up before him
In the face of Hiawatha,
Saw the beauty of Wenonah
From the grave rise up before him.
"Welcome!" said he, "Hiawatha,
To the kingdom of the West-Wind!
Long have I been waiting for you!
Youth is lovely, age is lonely,
Youth is fiery, age is frosty;
You bring back the days departed,
You bring back my youth of passion."
But this passage communicates a secret of parenthood, something I've never seen discussed anywhere else. By the time you're a parent, you're on your way to being old, ugly, tired, and cynical. I certainly was. This felt like a brute fact about the world: we all know time only moves one direction. Then I had kids, and got confronted with people who were basically me, but young and beautiful and happy. That part of them which wasn't me was the other person I love best in the world, also transmuted into a young and beautiful and happy form. This was a completely unexpected delight which nothing besides this one fragment of poetry had ever tried to prepare me for.
I might never have noticed this if I'd only had girls. I love my daughter, but I've never been a little girl; it doesn't bring anything back for me. It's like Mudjekeewis says - you've got to have a son to see your youth rise up before you.
https://www.astralcodexten.com/p/chip-off-the-old-block

In recent posts on Trump and dictatorship, people have asked me - how do you know you're not suffering from Trump Derangement Syndrome?
I take this seriously; we've all lost loved ones to this condition. The best check on my reasoning would be an objective measure of the health of American democracy. There are several "democracy indices" that purport to do this, but they have a mixed reputation. My impression is that most current accusations of bias are relatively weak - I agree with Claude's analysis here - but they rely enough on "expert" opinion that I don't expect them to convince a skeptic.
The newest entrant in this space - Metaculus Democracy Threat Index - works differently, and deserves a closer look.
Metaculus is a prediction site - like a prediction market, except that no money changes hands. People can record their guesses for how future events will turn out, which get aggregated by an algorithm (currently just a recency-weighted median, although they've done fanicer things in the past).
Their Democracy Threat Index is a collection of 153 questions relevant to US democracy. For example:
https://www.astralcodexten.com/p/the-metaculus-threat-to-democracy

The most controversial part of last week's article on the Midjourney ultrasound scanner was medical experts' recommendation against whole-body screening (including existing whole-body screening technology using MRI).
Isn't this crazy? Whole-body screening can save lives by detecting serious diseases like cancer. The experts counterargue that it finds so many false positives - minor zit-like imperfections that would never have caused problems, but which cost patients time, money, anxiety, and side effect burden to investigate - that it ends up net negative. But isn't this just a problem of setting thresholds correctly? Can't you commit to only investigating the most obviously bad things, then ignore the rest?
This seemed like an interesting problem to investigate in more depth, so I've tried to get numbers. These are rough estimates loosely based on parameters extracted from unsatisfactory studies1 - please don't take them seriously as exact values, just as right-order-of-magnitude estimates. We'll focus on whole-body MRIs, since this is a well-studied existing technology, then speculate later on how the results might generalize to whole-body ultrasound.
https://www.astralcodexten.com/p/should-people-avoid-whole-body-screening

like that, except from a medium-sized startup instead of a tech giant.

Earlier today, they announced a pivot to medical scanners. The new MidJourney Scanner, which they describe as "a bold new kind of machine to reimagine the foundations of healthcare and our relationships to our bodies", will be a tank of water surrounded by a ring of ultrasound scanners. The patient goes into the tank, the scanners emit ultrasound from all angles, and then some fancy AI reconstructs the echoes into a 3D picture of the body. The result is ultrasound tomography: the same sort of rich data as a CT or MRI, but done via ultrasound, with no harmful radiation, in twenty seconds.
This is cool, and it's great to be ambitious, but I think the narrative among the SF AI crowd has escaped its basis in the medical facts, so I want to throw a bit of cold water on it. I'm a psychiatrist, which is about as far as you can get from radiology while still being a doctor, so this is speculation only, and you can ignore it if you find an actual radiologist or ultrasonographer with opinions. Still, my take is that this scanner isn't useful for most current serious medical applications. It could potentially be used to pioneer a new class of low-risk screening applications, but it's unclear whether these are good, and depends a lot on what other future technology gets invented in parallel.
https://www.astralcodexten.com/p/preliminary-thoughts-on-the-midjourney