Astral Codex Ten Podcast

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

In 1917, three children in Fatima, Portugal claimed to have seen the Virgin Mary. They promised she would perform a miracle on a certain day in October. Nearly 100,000 pilgrims arrived, hoping to see whatever happened, and nearly all report that the sun turned pale, changed color, and spun around.
Many other writers have investigated the children and their visions, but I was fixated on this sun miracle. Despite popular discussion of "mass hallucinations", this is AFAICT the only example of tens thousands of people all saying they witnessed the same impossible thing, at the same time. I got kind of obsessed with this; you can read my preliminary investigations in this, this, and this post.
One of the first things I found was that there were many other sun miracles - at least ten! - similar to Fatima. Most were associated with Marian apparitions, but one was at a Buddhist temple. Bigfoot only gets sighted by lone hikers; ghosts are only ever in the corner of your eye; UFOs are just blurs in the sky. Of all the countries and outposts in the vast empire of the unexplained, it's only this one phenomenon - the spinning, multicolored sun - that regularly gets seen by thousands of people at once, in broad daylight.
Speaking of "regularly", there's one spot where it continues even today. Fifty years ago, the Virgin Mary appeared to six children in Medjugorje, Bosnia. Now those children are well past middle-age, but she continues to come. Three of them report that she's appeared less frequently as the years go by, but the others still see her every day at 6:40 sharp. Travelers to Medjugorje, especially those passing through around 6:40, report a slew of miracles, including the spinning sun. Certainly this is true of those whose hearts are pure. But even the atheists get lucky sometimes.
I was shocked never to have heard about this before. There's a place you can just go, and have a decent chance of seeing a real miracle? People take vacations to the Bahamas for the beaches, when they could go instead to Medjugorje and see the natural law of the universe get violated in real time? Seems crazy!
So in early April, I and my extremely-accommodating, long-suffering wife flew to Dubrovnik, rented a car, and drove down a series of windy mountain roads toward the Bosnian border, hoping for a miracle.
https://www.astralcodexten.com/p/waiting-for-the-miracle

Guest post by Alexander "Sasha" Putilin
[This is a guest post by 2024 ACX grantee Sasha Putilin. I encourage any ACX grantees who are interested to write about their projects. - SA]
The results of my ACX Grants 2024 project are in.
The project attempted to replicate the 2023 study "Learning at your brain's rhythm: individualized entrainment boosts learning for perceptual decisions". It claimed that if you read a person's brain waves, figured out an individual peak alpha frequency, and flashed a bright white light at that frequency, then they learned a certain perceptual task faster.
Why bother? The result hinted that learning may depend in part on how well the brain keeps its rhythms coordinated. In other words, perceptual learning may rely on an internal brain metronome. If flickering light could act as an external metronome, it might help the brain maintain the right rhythm and learn faster.
The study offered an invitation to develop new frontiers of neuroscience and biohacking. If the effect generalised to other types of learning, you could build a learning helmet: put it on your head, let it read your brainwaves, flicker light tailored to your individual brain — and you learn a new skill quicker.
And no, it didn't replicate. Most likely it can't replicate, because the effect is probably not real. The original study obscured the data with summary statistics. Running a $32,000 replication was excessive. We could've caught the issue with this study if we simply looked at the original data carefully.
*record scratch* *freeze frame* Yep, that's me. You're probably wondering how I got here. Here's the story.
https://www.astralcodexten.com/p/never-cross-a-river-four-feet-deep