This is the weekly visible open thread. Post about anything you want, ask random questions, whatever. ACX has an unofficial subreddit, Discord, and bulletin board, and in-person meetups around the world. 95% of content is free, but for the remaining 5% you can subscribe here. Also:

1: Comments of the week: Timothy Johnson tries to explain why Taylor Swift is such a big deal; Waldo explains why regulated businesses might sue their regulators even when trying to stay on their good side; and Scott Aaronson sets the record straight on his beliefs about AI risk. And I previously said I couldn’t find the source of a poll claiming that the median American estimated a 26% chance AI would kill all humans, but an alert reader found it here. Remember that ordinary people aren’t good at asserting probabilities, and also that medians don’t always present the full picture; see the link for more details.

2: A few years ago I wrote about embryo screening, where people doing IVF with multiple embryos could determine which embryo had the healthiest genes and implant that one. That post focused on a the company called LifeView, mostly because they were the only ones offering the service at the time. Now new company Orchid Health wants me to mention that they are also offering this service. They claim to screen for more rare single-gene disorders than LifeView, as well as the usual polygenic screening for common problems like diabetes, obesity, and Alzheimers (although they may also be more expensive). Their Science and Clinician pages have more information, and their signup link is here.

3: A few years ago I started the Psychiatlist, a list of psychiatrists and therapists endorsed by ACX readers (though not checked by me). I let it lapse pretty badly for a while, but some good work by Erik Anderson and Josh Haas has it up and running again at Thanks especially to Erik for kickstarting this process (and by the way he is a therapist on the list, based in Southern California).

4: Since I was pretty gung ho about the Lumina tooth probiotic, I want to link the good criticism I found as a counterbalance (without necessarily endorsing it). Here’s someone from Hacker News doubting that it will colonize the mouth (or do much if it does) - though see comments below. Here’s an endodontist talking about how hard it is to study this or get any evidence that it works. Some other people pointed out that the graph on the post shows only 50% colonization after one year; Aaron says he has other information showing it eventually reaches near 100% colonization and he’ll get that to me soon. Some people were extremely skeptical about whether any of this was even real, so here’s an NYT article about the original Hillman research from 2004 that will hopefully put those doubts to rest. I agree that there isn’t proof of efficacy and it will be hard to prove that, but I think the suggestive evidence compares well to other supplements I respect (albeit not $20K supplements), and no one in the comments had a good story for why it would cause harm - so I chose to take the free sample. I’ll let you know if anything terrible happens to me! Till then, you can also check the prediction markets.

5: I was also hoping to link criticism of my kidney post, but the author has deleted it. My memory of the argument was that, although studies don’t find easily-measured disadvantages, you might still want to have a prior that donating makes you feel worse in hard-to-measure ways like tiredness. There are studies that say it doesn’t impact quality of life, but this is a very subjective measurement and maybe these studies are wrong. My counterargument is that I have seen people with one kidney do very high-level work and lead multi-billion dollar organizations, and also there are some pretty advanced quality-of-life screening measures that really do fail to show any effect. I can’t rule out that it affects quality of life only in advanced age (I suspect there are studies that will disprove this somewhere, but I can’t remember if the studies I saw looked at this subgroup). I continue not to believe this argument, but am providing it so as to not recommending a drastic action without presenting all possible counterarguments.

6: On Friday I asked people with interesting charitable projects to apply for the new round of ACX Grants. Reading the first few applications, I’m seeing some that would be a better match for angel investors. If you’re in this category and want to see some proposals, please email me at