The CNS contains dozens of "feedback loops". Any intervention that drastically alters the equilibrium point of several of those loops is generally a bad idea unless you are doing it to get out of some dire situation, e.g., seizures. That's my recollection of Huberman's main objection put into my words (because I dont recall his words).

Supplementing melatonin is fairly unlikely to have (much of) a permanent effect on the CNS, but you can waste a lot of time by temporarily messing up CNS function for the duration of the melatonin supplementation (because a person cannot make much progress in life with even a minor amount of messed-up CNS function).

A secondary consideration is that melatonin is expensive to measure quantitatively, so the amount tends to vary a lot from what is on the label. In particular, there are reputational consequences and possible legal consequences to a brand's having been found to have less than the label says, so brands tend to err on the side of putting too much melatonin in per pill, which ends up often being manyfold more than the label says.

There are many better ways to regularize the sleep rhythm. My favorite is ensuring I get almost no light at night (e.g., having foil on the windows of the room I sleep in) but then get the right kind of light in the morning, which entails understanding how light affects the intrinsically photosensitive retinal ganglion cells and how those cells influence the circadian rhythm. In fact, I'm running my screens (computer screen and iPad screen) in grayscale all day long to prevent yellow-blue contrasts on the screen from possibly affecting my circadian rhythm. I also use magnesium and theanine according to a complex protocol of my own devising.

Are Eliezer and Nate right that continuing the AI program will almost certainly lead to extinction or something approximately as disastrous as extinction?

A lot of people e.g. Andrew Huberman (who recommends many supplements for cognitive enhancement and other ends) recommend against supplementing melatonin except to treat insomnia that has failed to respond to many other interventions.

Surely you cannot change the climate of Antarctica without changing the climate of Earth as a whole.

The reason most dental practices were owned by dentists and their families rather than by investors before the passage of the affordable care act is probably that there is no practical way for the investors to tell whether the dentists running the practice are cheating them (e.g., by hiring his cousin to work at twice the rate at which the cousin's labor is really worth).

In contrast, VCs (and the investors into VC funds) can trust the startups they invest in because they pick only companies that have a plan to grow very rapidly (more rapidly than is possible if revenue scales linearly with such a constrained resource as dentist labor or oral-surgeon labor). When the proceeds of an IPO or sale of the company are several orders of magnitude larger than the amount invested, any "self-dealing" on the part of the execs of the company being IPOed or sold become irrelevant -- or at least easier for the investors to detect and to deal with.

Although private-equity funds gets paid mostly by IPO or sale-to-a-larger-company just like VC does, because they don't limit themselves to investments that have the chance of growing by orders of magnitude, they have a more difficult time raising money. They must rely more on loans (as opposed to sale of stock) to raise money, and what sale of stock they do do is to a larger extent to high-net-worth individuals with an expertise in the business being invested in or at least an expertise in the purchase, sale and management of mature companies where "mature" means "no longer has a realistic chance of growing very much larger".

During the dotcom boom, there was a startup out of LA whose plan involved search-engine optimization, but the young men running the startup decided to spend some of the money they raised to make a movie. When the investors found out about the movie, they hired private security contractors who teamed up with LA police to raid the startup and claw back as much of their investment as they could (causing the startup to dissolve). I offer this as an example that self-dealing is possible in a startup, but it is easier to deal with: when a private-equity fund gets together 100 million dollars to buy Kleenex Corp or whatever, then finds out that the execs at Kleenex are spending a significant amount of the corp's money to make a movie (which they didn't tell the investors about) they can't just walk away from their investment: they have to fire the execs and hire new ones or step in and run the corp themselves, both of which will result in an interval of time during which the company is being run by exec still learning about the company, which is a costly undertaking.

VCs are already doing this. They have offered to buy both the oral surgery practice and the dental practice I use in town.

Investors have offered to buy both, but why do you believe those investors were VCs? It seem very unlikely to me that they were.

I worry about that, and I worry about the first AI-based consumer products that are really fun (like video games are) because pleasure is the motivation in most motivated cognition (at least in Western liberal societies).

I've been a heavy consumer of health services and health information since 1985, where "health" here definitely includes mental health (and specifically the effects of childhood trauma).

YT started being my main source of insights about my health and how I might make it better about 3 years ago. During that time I've managed to improve my health faster than the rate I managed in the decades before that.

How do you assess the expertise of those YT creators?

A person could write a book about that (which would tend to overlap a lot with a book about general rationality). I've probably changed some habit of mine (diet, exercise, etc) about ten times over the last 3 years in response to learnings from YT. I watch carefully for effects of those changes. This watching process involves taking voluminous notes. E.g., I write down everything I ingest every day. So, that is one way I assess experts: basically I experiment on myself.

Even though I prefer the written word, I get most of my mental-health (and health) info from Youtube these years. These videos for example taught me important things about trauma, and I think I already knew a lot about it before watching them: https://youtu.be/QHUoSrCOBGE https://youtu.be/LAEB5DIPPX8.

Many hundreds of deep experts on health and mental health have made and uploaded to YT tens of thousands of hours of video, and it is significantly easier for me to find the deep experts on health and mental health on YT than it is on the textual web, but if you do not already know a lot about health and mental health, it might not possible for you to tell which YT creators are the deep experts.

The textual web is still superior for many queries / quests, e.g., what are the names of the active forms of vitamin B6? Do any of the experts who treat or research CFS consider disorders of oxalate metabolism and important component, cause or consequence of CFS (chronic fatigue syndrome)? But if the goal is to learn more about CFS or oxalates (rather than the connection or intersection of CFS and oxalates) or trauma disorder or a particular mental-health condition, I would search YT first.

Personally I’m interested in perspectives from developing world countries

I have nothing relevant here.