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Joined 1 year ago
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Cake day: June 18th, 2023

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  • Ok, I’ve done some double checking: The Bantu expansion is approximately what I thought it was. I believe the language group I was thinking about that survived the Bantu expansion was the Khoisan.

    My (very coarse) knowledge of this comes from a mixture of reading Jared Diamond (Guns, Germs and Steel) and from following it up with some Wikipedia. In short: The genetic makeup in a lot of the world is relatively dominated by the groups that were the first to adopt agriculture in their respective regions. Before the Bantu expansion, phenotypes south of Sahara were more varied, just like the phenotypes in the Americas were more varied before the corresponding “European expansion”, or the equivalent expansion that happened in South-East Asia (I don’t remember which society stood behind that one).

    According to Diamond, we can trace a lot of (most?) surviving human phenotypes and languages back to relatively few societies, which after adopting agriculture, more or less wiped out / displaced neighbouring cultures due to increased resistance to a lot of infectious diseases and massively increased food production / need for land. This mostly happened less than 10 000 years ago, i.e. far too recently for natural selection to have a major impact on things like skin colour, hair type, height, facial features, etc. afterwards.

    So: While major trends in phenotypes are of course a result of natural selection / evolutionary pressure in specific regions (resistance to skin cancer / sunburn vs. vitamin D production, or cooling down more efficiently with a wider nose vs. retaining heat with a slimmer one, or having an eye-shape that lets in more light vs. provides more shade), a lot of what we see today is simply a result of what phenotype the first group a given region that adopted agriculture had. This means that looking at the dominant phenotype in a region today will not necessarily give a good impression of what phenotype that is “optimally designed” to survive in the conditions of that region.


  • I seem to remember that the majority traits south of Sahara (black/very dark skin, and curly hair) can be traced back to something called the “great Bantu expansion”, which was essentially the result of a group of people with these traits developing agriculture and wiping out most other peoples south of Sahara, much like the Europeans did to the Americas.

    Some cultures south of Sahara did survive, which can be seen both genetically, and in some languages that are completely from other languages in the area (I believe the family of languages with “clicking” sounds is an example).

    I’m on my phone now, but I’ll have a double check and come back.


  • I am/was in the same boat as you: For a long time, I just didn’t care that I was giving away a bunch of information in return for convenience, and didn’t get why people cared so much.

    I don’t really know what triggered it, but at some point I became painfully aware that the only goal these companies have is to squeeze every possible penny out of selling me. I started noticing that the stuff they ask you to confirm is 95% stuff they want because they can sell it, or use it to get you hooked to their service, and 5% (at best) stuff they need to make the service good for you.

    This triggered a change in my perspective: Now it pretty much makes me sick to my stomach to think about all the companies that are drooling over me, trying to make a buck by getting me to click something I’m not actually interested in, or don’t actually need.

    These people have a vested interest in manipulating me, and by giving them my data, I’m giving them the tools to do it. I don’t want to be manipulated or sold as a product: That’s what made me start caring about protecting my data.


  • This will sound dumb, but I’m saying it sincerely.

    I’ve had similar issues (without getting into details), but what worked for me was getting outside a couple times a week. By that I mean bringing a tent or hammock + tarp and sleeping outside a couple nights a week on workdays.

    To be specific: I sleep outside Monday-Tuesday and Wednesday-Thursday. On those days I also make my dinner at my campsite. What I’ve found is that my brain goes into a much more “primal” state of “monke outside in cold, monke get shit done”, and that it propagates into my day and week.

    The barrier to this is of course actually going outside, but I’ve been able to get to a place where I have a “deal with myself” about those two nights a week. I always have my pack ready, so it’s just about grabbing it and heading out- I think that’s key.

    I’m not saying this is a solution for everyone, but it’s done wonders for me. As of now, I get restless and feel bad if I’m in a situation where I can’t get outside at least once a week. It brings me a peace of mind and will to get stuff done that nothing else can.







  • I would say “debunked” in the sense that quantum mechanics correctly predicts phenomena that don’t exist in classical physics, and relies on the idea that quantum particles obey a probability distribution, rather than deterministic mechanics.

    Quantum mechanics appears to work so well for these phenomena compared to deterministic mechanics that it’s tempting to say that the actual universe is in fact governed by probabilities rather than determinism.

    I would argue that all physical models of the universe are just that: Models. We can get asymptotically closer to a perfect description of the universe, but no model can ever tell us the true nature of the underlying system it is describing, just be an arbitrarily good description of it.










  • Of course, Li-ion batteries will never cover large-scale power demand. Not primarily because of lack of lithium, but because it’s a technology that scales far too poorly into the MWh/TWh scale, and has a far too short lifetime.

    The battery tech we need for truly large scale storage is different from what we need for small, portable storage. Stuff like redox-flow batteries are looking promising.

    There’s also hydrogen, with different storage methods being actively researched- from direct storage to using ammonia as a carrier.

    The issue with using mechanical storage (like pumped hydropower) is threefold (off the top of my head):

    1. It has ridiculously low energy density
    2. Even after > 100 years of pumps and turbines, the power loss in a pump/release cycle is very high.
    3. It’s heavily limited by geography

    I’m not saying pumped hydropower isn’t part of the solution: I believe the solution is that we need many solutions. I just think it’s important to point out that battery tech isn’t some monolithic thing, and that there are issues with pumped hydropower (and mechanical storage in general).


  • I’m all for age of consent, but considering that you can have graduates as old as 19-20, and teachers as young as 23-24, I have to admit it seems a bit strange to put restrictions on what they can do outside of (1) what is legal, and (2) what effects their job (like having a relationship with a current student, especially one that you teach).

    Like, I know several people in my graduating high-school class that were with someone older than our youngest teacher, a couple of which are still together with the person 10 years later.


  • Yes, there are an infinite number of velocities you can use, but if you look at their distribution, you’ll find that it quickly goes to zero somewhere around 1-2 m/s, so the expectation value of the velocity is convergent.

    If you have an object with a velocity taken from a distribution that doesn’t approach zero sufficiently fast as the velocity goes to infinity, the expectation value diverges. A simple example would be a person that would be half as likely to get up at a velocity of 2 m/s as 1 m/s, and half as likely to get up at 4 m/s as 2 m/s, etc.

    The more mathematical version of the same argument is to compute the kinetic energy of a particle whose wavefunction is a delta pulse (i.e. a particle whose position is exactly defined), and you’ll find that the particle has infinite energy.