>“No way. They’re partying all night.” But they can, because there’s no top-down pressure to go into the office at 8 a.m. They’re free to catch supplemental sleep as needed throughout the 24-hour period.
This feels like the key point to me. These societies follow their body and go to sleep when they are tried, while us in the west have to sleep at a specific time to fit our schedules.
47635274172635 3 minutes ago [-]
>while us in the west have to sleep at a specific time to fit our schedules.
This does seem to work great at group level. Considering we're in a competitive setup and all that.
I also recognize I personally benefit from others having this schedule. It would quickly go sideways if the firefighter felt like he wanted to sleep a bit more, or the police officer didn't really feel like it whenever is an emergency.
This is a contentious theory with little actual historical backing. Most likely people have been sleeping in one block since forever.
musicale 9 hours ago [-]
> Historical texts and recent research suggest an alternative view: that sleep can be naturally segmented into two periods across the 24h cycle – a pattern known as biphasic sleep
Pages 341 to 414 of size 8 font denoting the manuscripts that he sourced from would disagree with you.
preg_match 9 hours ago [-]
We have evidence that during the medieval period people did take two-sleeps. Whether this is the more "natural" organization is debatable. But it made sense for that time.
scotty79 1 days ago [-]
> Most likely people have been sleeping in one block since forever.
Does that have stronger historical backing?
layer8 20 hours ago [-]
There is a lack of historical writings clearly describing segmented sleep as a normal practice over monophasic sleep. If it had been the standard sleep pattern, one would expect abundant evidence for it.
Roger Ekirch’s theory, meanwhile, is based on what one could call a biased interpretation of a hand-picked selection of ambiguous sources.
scotty79 18 hours ago [-]
I asked if there's abundant evidence for monophasic sleep in historical writings. Or do we just assume it was monophasic, because there's not much written about sleep either way?
layer8 18 hours ago [-]
You were asking for historical backing. Sleep is definitely abundantly mentioned in historical writing, while segmented sleep is not. I take the absence of the latter as historical backing.
fittingopposite 4 hours ago [-]
Absence of evidence is not evidence of absence.
jnfnfkfkt 3 hours ago [-]
[dead]
hirvi74 12 hours ago [-]
I wonder how much time zones and seasons impact things. For example, in my city in the winter, it is often dark for 14 straight hours. No average, healthy individual would sleep for that long on a nightly basis. So, even if one slept for 7 hours at sunset, then there would still be 7 hours of darkness remaining upon awakening.
Point being, if one slept for 4-5 hours, wake up for a similar chunk, and slept the same amount again, then that'd be a great way to pass the time one could likely not use to do outdoor labor.
j16sdiz 22 hours ago [-]
It is more common in high-latitude countries.
Very uncommon in lower latitude.
IAmBroom 17 hours ago [-]
Another unbacked claim.
jnfnfkfkt 3 hours ago [-]
[dead]
mark_something 22 hours ago [-]
But the article discussed here also points in that direction when it mentions the importance of people on the lookout at night. The article also mentions primitive tribes partying all night, so that is yet another direction.
euroderf 17 hours ago [-]
My boy when very young (just months) went thru a phase where in the middle of the night he would suddenly sit bolt upright, swivel his head to scan the room, and then conk out again. This was not caused by noises.
I found this reassuring and slightly amazing, that he is wired to do his part as a nighttime lookout.
hirvi74 12 hours ago [-]
Assuming you are not jesting, I am not certain I would qualify that behavior as any indication of being wired for some sort of nighttime patrol duty based on those details alone.
euroderf 4 hours ago [-]
Not jesting! And, point taken. But it made me wonder. It was intentional (within the limits of intentionality for an infant) and repeated.
IAmBroom 17 hours ago [-]
When I was in my early 20s, primitive tribes like Alpha Kappa Lambda would party all night.
That doesn't mean they didn't sleep all night, typically.
I would also imagine a single block of sleep is relatively new due a host of various factors. Especially when considering untreatable medical conditions, chronic pain, parasites (bed bugs, lice, etc.), lack of comfortable bedding, cohabitation with others, and plenty of other factors all had major impacts.
i_love_limes 1 days ago [-]
I think people in HN (and in general) have to remember the central axes of evolution before digesting this kind of article. I've already seen comments like it's "odd that no species has ended up evolving a continuous maintenance system" and "sleep has a higher opportunity cost in humans" in this comments section.
This is a common, but poor framing of evolution. Remember: the only real rule with evolution is "did this evolutionary change mean they survived / reproduced more"? Evolution is not a local or global maxima solving function. I find this kind of attempt at interpreting selection common with engineers, programmers, etc.
hackernud3s 1 days ago [-]
Did their genes survive more, you mean. Hyper-vigilance could be maladaptive for the individual and still survive if it benefits others that carry the gene for it.
vintermann 23 hours ago [-]
A bit of a digression, but I recently learned about the concept of pangenomes, of trying to map not just the genes in one individual, but the entire set of genes from a clade. It seems it matters a lot in practice for e.g. the immune system that we don't all have the same surface proteins on our cells, even if done some surface proteins are clearly better than others.
yuretz 1 days ago [-]
I can see why it isn't a local or global maxima solving function, but it surely can be modelled by one, right?
teekert 1 days ago [-]
I'm a biologist so forgive me the poor wording, but there are "infinitely high" peaks/walls in the evolutionary landscape, as in: "the human urinary system has some evolutionary constraints and anatomical features that are not optimally designed from an engineering perspective, but they are generally functional and reflect our evolutionary history rather than deliberate design." <- this is from AI, I didn't remember the details, but the ureters or urethra take a long way around the inner part of the body because at some point it was a good route, but as we evolved it became suboptimal, but we can't just evolve to untangle all the pipes in our body and do some cable management... We're stuck with what we have (no tunneling electrons ;)).
So in that sense, a global maxima (minima?) solving function will probably not arrive at what we have, it has to take into account our evolutionary path, in its entirety (as in the whole tree.), because it is all encoded in 1 (or several) long molecules, and a radical changes would take a rewrite of many parts at the same time, which just does not happen. Maybe at some point we can do it ourselves... though I imagine there being a lot of unintended consequences in other places in the body :).
Another example is that sometimes complexity in a cell signalling cascade is simply there to get some timing right (ie delay some response), and the complexity is just there, and won't simplify by itself -> But then later the complexity may start to serve some purpose. Just like proteins that are "copypasta-ed" in the genome, leaving one copy free to mutate and attain a function, or not... etc etc.
dtech 24 hours ago [-]
That is the difference between global and local optima.
We're not at a local optimum though, our bodies can probably evolve to produce half the urine or something without changing the route, but there is no evolutionary pressure to do so.
teekert 24 hours ago [-]
Yes, but we cannot evolve to have our urinary tracts take a more efficient route (or at least the probability is exceedingly low), even though there would be pressure to do so. (Maybe I'm misunderstanding your point)
I did not know human urinary tract was suboptimal.
Are there examples of "discontinuous" evolution where a chance mutation stumbled upon a much better way to do something that allowed a species to jump the gap?
I imagine it would be very rare because chance mutations in a single individual that confer extraordinary survival / mating advantage to offset entire population would be rare like being a superman among men.
teekert 23 hours ago [-]
"I imagine it would be very rare because chance mutations in a single individual that confer extraordinary survival / mating advantage to offset entire population would be rare like being a superman among men."
-> This also depends on population size, if there is a bottleneck event (ie 99.99 percent of some species dying) then among the 100's of survivors perhaps there could be a superman. Either because this person got lucky, or the rest got unlucky. But in general the distribution of traits is quite continuous, given large populations.
It's also good to keep in mind that us biologists have messy definitions, ie we call specimen A and B the same species when they produce fertile offspring. Some species produce offspring but infertile (Horse-Donkey, Lion-Tiger). But what if A and B have fertile offspring and B and C do, but A and C do not? The whole definition of species falls apart (it leads to a paradox).
We have a lot of that in biology. You need to learn to deal with it (sunglasses dropping down), and assign uncertainties to terms you learn about, they are often just our attempts to name boxes on continuous, multidimensional scales.
teekert 23 hours ago [-]
Well, what is suboptimal... One would engineer it differently, it makes a weird, seemingly unnecessary, loop around some other tracts. However, being a biologist I can also imagine that if we'd reroute the thing in someone using surgery, that person suddenly gets more infections because bacteria find their way up the tract more easily (no idea, but could be!). The point is... It's a mess based on some earlier mess, but it works, and changing one part in this mess can lead to unpredictable results.
As for "discontinuous evolution"... Again, what is discontinuous? I'm sure there are events to be found of which the probability of them occurring is so small and the effects so large that they'd fall into someone's definition of "discontinuous". But I think there is by definition no such thing as discontinuous evolution. If it occurred, it had a non-0 probability of occurring, then again, maybe the universe is infinite and everything has a non-zero probability of occurring. This is getting philosophical haha. Maybe listen to some Mindscape podcasts (Sean Caroll).
Actually rabbits eat their excrement again. That's also probably not how an engineer would make it (or an intelligent designer would design it, since we seems to be going in that direction ;) ).
PetitPrince 21 hours ago [-]
Antibiotic resistance happens all the time (at least in our artificial world) and it's a life or death situation for the bacteria.
But you were probably asking for multicellular eukaryote organism; you may be interested in the concept of saltation https://en.wikipedia.org/wiki/Saltation_(biology) . Behind the concept of the thing itself it's interesting to think about the mechanism behind it. Regular evolution is gradual (point mutation leads to a maybe slightly different protein, which has only a relatively small scale effect but you gain or lose function over many generation), but for a saltatory evolution you most probably need radical changes in the DNA, like duplication (of a single gene, multiple gene or whole chromosome), horizontal exchanges, etc.
It's possible in plant but in animal more often than not it's not beneficial at all to have such event. Famously if you have an extra chromosome nr. 21 you get Down syndrome.
yeoyeo42 22 hours ago [-]
no offense, but it just sounds like you don't understand local maxima in high dimensional spaces.
a suboptimal trait evolving that still provided an overall population benefit (via survival or reproduction) with further improvement close to impossible without a multitude of large changes is literally just a local maximum in that high dimensional space that maps traits to whatever success metric you're measuring.
the infinite wall you describe is not a wall in that space. actually I originally wrote its more like a wall in the derivative space but its not quite right either, those just point straight down from the maximum.
teekert 22 hours ago [-]
Perhaps not no, please enlighten me, where is my lack of insight?
Edit, thanx for the addition. Perhaps my issues with looking at it as "local maxima in high dimensional spaces" (even though we think of minima usually, as in a marble will find the minimum in a landscape with gravity pointing down, sorry I'm a biologist) is that with every mutation and every change in environment the landscape changes (so basically with time), is it still a useful way to think about it like that, at that point? So it not a "landscape in a high dimensional space", but rather a "high dimensional dynamic surface", like a sea?
teekert 1 hours ago [-]
... In fact, because te landscape is so dynamic and can sometimes change within 1 to a few generations, having a brain as the primary store for behavior/customs/models/information is super advantageous compared to using DNA, as the brain is a flexible neural network and can adapt much, much quicker. No doubt this is why we are successful (ie, a dung beetle will die trying to push a stuck piece of dung, because the behavior is hard-coded and it cannot model the world and model solutions to encountered problems, and it therefore cannot pas solutions on to future generations, as we can. Perhaps a dung beetle will someday mutate to alter it's behavior when stuck, but you can see how suboptimal the whole process.)
i_love_limes 24 hours ago [-]
Great question! It maybe can be, but what is the maxima that is being solved for exactly? There are usually tradeoffs, the most common and prevalent is our body's immune response. If it's under-active, we might die from an infection. If it's over-active, we get diabetes, lupus, chron's, and (probably) lots of mental health disorders.
So, it's a bit context dependent, and definitely dependent on other mutations that have occurred in other parts of your DNA. Most complex diseases are "polygenic", meaning it's a culmination of quite a few factors that would contribute to a specific good or bad outcome.
So, yes, it could be modeled as a sort very context dependent with a lot of highly correlated non-independent covariates. We do use quite a lot of statistical and ML methods to understand the genome (I work in statistical genetics), but the complexity of biology has so far proved a tough nut to crack.
codethief 22 hours ago [-]
> It maybe can be, but what is the maxima that is being solved for exactly?
Survival rate/reproduction rate/rate of genes being spread?
PetitPrince 21 hours ago [-]
I think you're correct, but only if you add "for a given environment". It's good to develop the ability to store super efficiently fat when you're a Pacific Islander and food is scarce, but this advantageous trait becomes a liability with modern and plentiful (junk) food.
see thrify gene hypothesis; I know it's not a good explanatory theory but it's a good illustration of my point
codethief 19 hours ago [-]
Sure, the form of the function being maximized will usually depend on the environment.
i_love_limes 1 minutes ago [-]
That was kind of my initial point... there are far too many permutations that alter what you want to maximise to consider this as a good option right now. Environment, gene-environment interactions, epigenetics, polygenecity, pleiotropy, etc, etc.
yuretz 23 hours ago [-]
Great answer! Thank you!
dtech 24 hours ago [-]
Evolution is the ultimate "good enough". Once the required threshold is passed, pressure stops. The threshold might constantly be moving due to competition, environment etc.
tempfile 21 hours ago [-]
It can't be a global one because it is inherently local. Evolution is a process which determines the next time step (generation) from only the previous generation. It has no memory at all nor "knowledge" of other reproducing pairs.
FallCheeta7373 24 hours ago [-]
To be precise inclusive genetic fitness not idealized bayesian optimality.
Kim_Bruning 20 hours ago [-]
> "did this evolutionary change mean they survived / reproduced more"
You're just renaming the terms. More/less is a fitness gradient, and the thing that lives there is called an optimizer.
Evolution is a tunable-scale optimizer. It's not perfectly local, because it shotguns to avoid local optima on a (bumpy/noisy) fitness landscape. If you tune the 'shot pattern' really wide (infinite copies with infinite variation), you'd genuinely get a one-shot global optimizer at the limit. But that's not efficient nor realistic, so typically it's somewhere in between.
Uh, compare maze solvers: you've got your greedy direct route (gets stuck in the first corner) , Dijkstra (finds all the answers but takes ages), and then stuff like A*, which is a happy medium. Evolutionary algos can be used to solve mazes just the same. I think it's a bit heavier on resources than A*, but well suited to embarrassingly parallel optimization.
edit: Heh, I actually had claude build a comparative simulation. Turns out evolution is actually very slow on a single optimization axis, and gets stumped in mazes where the detour length is greater than the "temperature"/"spread"/"noise". The actual performance metrics are fascinating. But once tuned, it is able to solve mazes. Thus an optimizer. QED :-P
duskdozer 24 hours ago [-]
>18 degrees Celsius is considered optimal for sleep depth
I'm instantly skeptical of anyone making universal statements like this, because they're certainly not true for everyone, and having looked into these and similar (f/x "ideal room/office temperature"), are based on many entangled assumptions. Most of the time I expect it's just people making after-the-fact justification for doing (or imposing) what they most prefer.
ViktorRay 23 hours ago [-]
When statements like this are made usually it’s because studies would have been done comparing sleep depth at different temperatures and there would have been a statistically significant increase in sleep depth at 18 degrees Celsius in the tested group compared to groups sleeping at other temperatures.
I have no idea if that was actually done here but that’s usually how these statements are justified.
Of course we are all individuals so it may not apply to everyone but you can say that for everything in medicine. Only thing we can do is look for statistically significant differences between groups in double blind controlled studies after controlling for all other factors.
giov4 22 hours ago [-]
yeah probably lot of study measurements and data confirming that, I'm not skeptical about it, to me it feels like something scientifically measured proven since quite some time already. of course genetics and outliers still need to be considered.
also do you know that the body temperature decreases during sleep? based on that I simply deduce and assume the more the difference between body and room temperature the more side effects arises for sleep, of course simplifying without ignoring all the rest.
IAmBroom 21 hours ago [-]
And every time I hear about an optimum, I think of the Bathtub Curve.
As I imagine the curve, I use a real bathtub. Where is the water deepest? At the drain, which is typically just under the faucet. Where is the optimal place to sit? Well, pretty much anywhere except there, because "deepest" (an optimum) isn't enough to accurately gauge "best place". But even if you can swing the faucet out of the way... where is the optimal place? Anywhere on the bottom, a broad, slow curve, as opposed to the steep walls or rim.
So, if 18 degrees C is the optimum, what's the standard deviation? I bet it's not 0.1 degrees. Could be 2 degrees - and that would mean concentrating on 18 degrees is a distraction, not a goal.
This is something evolutionary discussions don't address well, either. If a gene line (species) has a pressure to change, it can "settle" for any place on the bathtub floor (when the solution is shaped like that). This is another example of evolution not seeking an optimum; merely avoiding a pessimum (a word I just googled, and like!).
In fact, it doesn't even matter if it's a bathtub curve. Maybe it's a slope, like the amount of capsaicin a pepper plant carries to fight off fungus. More better - but it costs something to make, so just make enough to ensure survival. More fungus? Increase capsaicin production. There's no floor to this bathtub; it's a linear slant all the way down to maximum possible capsaicin content (which, amazingly, is about 10% by weight of the fruit cells!!!).
tharkun__ 9 hours ago [-]
18C is more like the maximum OK temperature. But then I also gotta sleep without PJs when its that hot. Still a blanket for comfort.
Best sleep from my experience? It's usually about 5C at the thermostat, which is farthest from the window, by the time I wake up. And that's likely because it's in the basement, which is a typical NA basement, so you have the uninsulated and below the frost line basement wall there. The cold air coming in will be 0C and colder and I sleep next to the window. Winter is my happy sleep time.
devilbunny 8 hours ago [-]
If you are wearing clothing or any covering, clearly it isn’t your optimal temperature. I’m not trying to be glib here; I understand the appeal of being warm in a cool or even chilly room with air that keeps you from overheating. But that’s not sleeping at the optimal temperature; it’s choosing the sleeping setting you like.
And there are huge swaths of the world where the temperature basically never gets that low (18 C is the lowest temperature ever recorded in Kingston, Jamaica; 16 along the coast of west Africa, 18.9 in Jakarta). Even here in the southeastern US it is normal for temperatures to stay above 20 C at all times for three full months of the year (late June through early September).
Nothing wrong with liking to sleep in cold air, but it’s a preference.
tharkun__ 6 hours ago [-]
Your feeling might be different. But for me, body temperature and feeling is way different from the air I'm breathing.
I can be, actually want to be toasty warm under the blanket. But I want the air I am breathing to be fresh and cold. That is when I feel comfortable and "at peace".
I will often stick out my feet from under the blanket because it's way too toasty but the rest of my body needs to be warm.
Sure, when it's 25C I'll essentially just lay there without anything but a sheet across the chest to "feel safe" but anything else will just make me way too warm and the air I'm breathing will feel restricting.
What is really great in 25C+ temps is to be outside in a hammock without an underquilt, which cools things down considerably. But I've also slept comfortably at 0F (-18C) in a hammock. With two underquilts and a 0F sleeping bag as well as a winter tarp with doors and snow cover all around, weighing down the tarp sides (wind does suck at that temp ;)).
duskdozer 5 hours ago [-]
>18C is more like the maximum OK temperature.
For you, and that's kind of my point. For me, my preferred temperature would be about 28C with no blanket or a light sheet. Something like 18C can be tolerable with blankets for me, but it's certainly not "maximum comfort", even with blankets. There is too much variation and too many things that wouldn't be controlled for, like number/thickness of coverings, and other such things. Having some "best" universal temperature is just not something generalizable like this.
Obscurity4340 14 hours ago [-]
If you want a tried and tested heuristic it should be cold enough to make you retreat to hibernate under a mountain of blankets roughly equivalent to or exceeding the warmth of a polar bear's coat.
Then its good night, Irene
GeoAtreides 23 hours ago [-]
[dead]
23 hours ago [-]
hlynurd 1 days ago [-]
>the Hadza uniformly reported high satisfaction with their sleep.
And why wouldn't they? This is (presumably) the only kind of sleep they know.
bialpio 1 days ago [-]
Do you really need to know other kinds of sleep in order to know if you feel like shit after waking up or if you feel fine?
hlynurd 23 hours ago [-]
If they have no frame of reference then it seems like their general contentedness is being measured (or as another commenter indicated, their willingness to gripe.)
IAmBroom 21 hours ago [-]
Yes.
Even in your example, you propose an individual could know multiple kinds of after-sleep feelings.
hobo123 18 hours ago [-]
I believe that how you feel after a night's sleep is mostly due to nutrition (long term, not just the day before).
agos 17 hours ago [-]
that might be true unless we can define what nutrition can help with sleep. There's plenty of people who eat well and sleep like crap.
rob74 1 days ago [-]
They're probably also less confronted with articles/videos/social media posts telling them they're doing it wrong and how they should sleep instead. Sometimes ignorance (or rather, not overthinking things) is bliss...
mark_something 22 hours ago [-]
True. But the article mentions that the amplitude of their circadian rhythm is higher (which tells you how much a relevant measure like the amount of melatonin or body temperature varies in a 24 hour cycle), so that is an indication of better sleep. A low amplitude means less difference between sleeping and being awake.
oulipo 1 days ago [-]
Well probably us modern human only know the "8h sleep at night" kind of sleep, yet a lot of people would tell you whether they're satisfied or not with their sleep
voidUpdate 23 hours ago [-]
I mean I can vary from 9 to 3 hours of sleep a night, and I can tell you I'd rather get 9 than 3. Just because I'm meant to get 8 hours a night doesn't mean I do
readthenotes1 23 hours ago [-]
Also, they may not want to complain to strangers.
Also, we humans can get used to a lot of things and just be okay with it. For an extreme example, look at domestic abuse victims...
syllogism 1 days ago [-]
This interview feels weird to me, maybe because there's lots of places where I'm thinking there's an obvious idea that isn't raised.
Like, it seems obvious to me that sleep has a higher opportunity cost in humans than most other animals. So naturally there's more evolutionary pressure in humans to sleep more efficiently.
Is this actually true? Dunno! But it was really weird that it doesn't get brought up.
fhn 11 hours ago [-]
"we’re the shortest sleeping primates, yet we pack in the most REM sleep relative to this short duration."
Nothing surprising here. We sleep in cozy comfortable beds in a locked and secure location. Of course we'd can get int REM sleep. Compare to other primates who sleep outside with the critters and predators, deep sleep could mean the end of them.
samtheDamned 6 hours ago [-]
My understanding is that REM isn't particularly deep. Quick web searches aren't actually defining it as more like light or deep sleep, but many of our systems are more active than other stages[1][2]. Still I don't think it's super surprising that we spend more time in REM since our brains are uniquely complex and we spend a lot of energy on perception and interpretation, which REM seems to help with [1][3]. And I would be willing to be safety and comfort also play a decent role in it as well!
Probably the only primates where a significant portion spent tens of thousands of years isolated up in the Arctic during prehistoric times.
Where the sun doesn't go down every single day anyhow, and you may need to trudge across the tundra routinely for more than 24 hours at a stretch to get almost anywhere, without ever worrying about it at all.
Then they later came down and intermixed with (not) everyone else, so you never know who is going to be less tired than "normal" when they work a 36-hour day.
Flashtoo 1 days ago [-]
> Some emerging research suggests Earth’s magnetism matters, as well. Being barefoot on the ground versus 30 stories high in a downtown skyscraper puts you in a completely different magnetic environment.
Really? My instinctive reaction to this statement is that it's quackery. Would be very interested to see headlines appear about this if it's true.
alex43578 1 days ago [-]
It's definitely quackery. There's way more "natural" magnetic variation between two different cities than between a ground floor apartment and a 30th floor apartment (see magnetic declination maps), and that's even before you get into the way-more-powerful magnetic fields generated or present in a home.
iammrpayments 1 days ago [-]
You can write pretty much anything you want after “Some emerging research suggests”
randusername 22 hours ago [-]
This is called "grounding" or "earthing" and Wikipedia doesn't pull punches in dismissing it [0]. You can buy grounding wires for your mattress or copper rivets for your shoes.
From my tissue engineering class in undergrad my 2 cents is this is maybe 95% supplements quackery and 5% genuine mystery. You can find papers that claim EM fields have cellular interactions [1]. I don't think serious scientists will touch conventional earthing, though.
More evidence this may have been written by a pigeon...
eru 1 days ago [-]
People already live in different altitudes, ie with vastly different amounts of rock between themselves and the bits of the earth that produce her magnetic field.
So colour me skeptical of this claim as well.
And while I like going barefoot for other reasons, I don't think it makes much of a difference to the magnetic fields.
krige 1 days ago [-]
> People already live in different altitudes, ie with vastly different amounts of rock between themselves and the bits of the earth that produce her magnetic field.
It's not really the same thing. Construction and especially the high content of charged metal (whether it's power conduits or plain old frame) may make a considerable difference.
dolmen 1 days ago [-]
What about flowing underground water when sleeping on the ground?
What about the metal frame of a bed?
dotancohen 1 days ago [-]
Do many people sleep in such tall buildings? Obviously they exist, but I can't think of any over-20 story residential building I've ever been in. Office space, sure, but not residential.
nkrisc 23 hours ago [-]
The amount of people who would regularly sleep in such a building is a minuscule fraction of the world population.
Yes, like I said, these things exist. But I ask do significant populations of humans reside in the upper floors of such structures?
eru 9 hours ago [-]
In absolute terms, yes. In relative terms, no.
IAmBroom 17 hours ago [-]
You forgot to mention whether they slept near shakra-aligning crystals or not.
That may make a considerable difference.
And I may be a 10,000 year-old alien.
fuzzfactor 6 hours ago [-]
>I may be a 10,000 year-old alien.
That would be so disappointing, I've been picturing you as Mickey's assistant in Fantasia :)
Then again, maybe that checks?
giov4 21 hours ago [-]
I would not jump to such conclusions, I would assume is not fully known and needs to be further understood.
on the other side, do you know we have polarized and non-polarized cells? do you know they can be affected by electromagnetism?
this two things already establish the existence of a relationship and effects between them. If we then consider that cells mechanism work based on differential of electrical or chemical potentials, and that they continuously use that for their functions, reactions or environmental compensations well...
I just think they are related and we need to understand better.
Some animals - migrating birds, notably - can detect magnetic fields. IIRC, sharks have close-range magnetic sensors in their gumlines.
But these are extremely rare and niche adaptations to difficult problems.
LYFMail 1 days ago [-]
It's a creative innovation!
mark_something 22 hours ago [-]
> Most importantly, when we measured their circadian function directly, small-scale communities had much higher amplitude circadian rhythms than global north populations, which I think is why they report being happy with their sleep even though it’s more fragmented.
This could explain why I feel more rested when I wake up if I take glycine before going to bed, even though I don't sleep more.
montebicyclelo 1 days ago [-]
More fragmented sleep, with people talking in the night, etc. I guess that's different from the low, unnatural, rumbles of cars and aeroplanes the majority of people have to put up with.
yard2010 1 days ago [-]
I could only wish for low unnatural rumbles of cars. In 3rd world countries it's non stop horns and noisy motorbikes
HappyPanacea 1 days ago [-]
Car horns gotta be up there as some of the worst inventions of the 20th century, noise pollution galore.
jbuhbjlnjbn 23 hours ago [-]
It works when you have strict rules on the use of horns and people get peer pressured into adapting to the behavior of their surroundings.
abigdog 23 hours ago [-]
737s are fine its dog barking that gets me.
Pearse 1 days ago [-]
I actually find it easier to sleep with the sound of people talking around me, it's very comforting.
YLYvYkHeB2NRNT 24 hours ago [-]
A nap is the same as sleep, but we don't do this. Any correlation to our southern american friends and their siestas?
giov4 21 hours ago [-]
I tried to imitate japanese people in the public transport when i was there, meaning I managed to kinda sleep/nap with eyes closed for 10-15minutes between rides and it was astonishing.
while I understand might be a more known thing, it was surprising to try it and feel very rested after that. I'm still surprised and I wonder why not the whole world does it.
of course without the music at the stops would not be possible :P
vinyl7 11 hours ago [-]
Growing the GDP and Shareholder Value is more important!
tempfile 1 days ago [-]
The article title is "Where human sleep went wrong" but then the entire article is about how we sleep the best we ever have, we have the most high quality sleep, and all the fearmongering about sleep is basically wrong.
moffkalast 1 days ago [-]
> Sleep is critical to human functioning, and yet, we sleep fewer total hours than any other ape, and are still arguably the most evolutionarily successful of the primates
> humans are weird outliers—we’re the shortest sleeping primates, yet we pack in the most REM sleep relative to this short duration
Isn't that sort of the point? Sleep is a detrimental necessity and the more efficient an organism is in needing less of it, the more effective it can be because it simply has more time to get ahead of the others?
It's still very odd that no species has ended up evolving a continuous maintenance system that can run while conscious, the benefits when hunting other animals that need sleep would be enormous, so there has to be significant evolutionary push for it. I suppose the single hemisphere sleep some marine mammals do is part of the way there, but it is at most a lazy workaround. Practically all other organs have evolved to run 24/7 for up to a century without a single break, what makes brains so universally different?
Unihemispheric sleep has been used by cults for mind control because it puts you in a vulnerable mental state (for example https://zizians.info/#unihemispheric-sleep). So anybody reading this and interested in trying it, ensure you’ve done sufficient research first.
exceptione 1 days ago [-]
> It's still very odd that no species has ended up evolving a continuous maintenance system that can run while conscious
Great point. Afaik, our bodies do preserve energy when we sleep/rest. A few questions that needs to answered first:
- will gains of 24/7 hunting/foraging offset the extra energy costs? Lions sleep 16-20 hours a day, according to the internet.
- do continuous maintenance systems imply duplicate systems? If so, I have a hunch that even a mere 40% increase in energy expenditure would quickly undo the gains in waking hours.
23 hours ago [-]
aqme28 1 days ago [-]
> It's still very odd that no species has ended up evolving a continuous maintenance system that can run while conscious, the benefits when hunting other animals that need sleep would be enormous, so there has to be significant evolutionary push for it.
I disagree. Endurance hunters walk an animal down throughout a single day. Sleep isn't the bottleneck. Efficient bipedalism and sweat are enough.
1 days ago [-]
salawat 1 days ago [-]
The fact they electrically signal via chemical analogs fuelled by immersion in nutrient bearing fluid that also accretes waste products, yet is kept separate from the primary loop of the cardiovascular system by the blood-brain barrier?
dotancohen 1 days ago [-]
But why is that fundamentally different from the technobabble description of any other vital organ?
salawat 13 hours ago [-]
Life has a surprising amount of detail, and if you're only curious enough to interact with the answer as 'technobabble', this does not speak well of your genuine curiosity on the subject. However, in general...
Form is shaped by function. The liver/pancreas are designed to handle the production of detoxifying/neutralizing agents that may in and of themselves kill nearby tissue, resulting in the propensity for notable regenerative capabilities. Kidneys/intestines are high surface area to provide more room for the physical processes driving selective permeability to occur, as well as habitable spaces for beneficial microbial symbiotes that aid in digestion. Skeletal/smooth cardiac muscles are optimized for energy burning to facilitate movement. Tendons/cartilaginous membranes are optimized for lubricating joints/connective tissue purposes. Tissues like the thalamus and tonsils, are there for immunity modulation and detection. Neural tissue however is all about signal propagation, and creating shifting networks of continuity that encode information and patterns, the tissue itself is just the medium, and that medium requires some process to clean out or reset the gradients in the synaptic gap. Otherwise, electrical charges cannot be consistently conveyed as flows of ions, actuated by releases of neurotransmitters into the bridge of the synaptic gap. The other constraint unique to neural tissue as well is it isn't motile, or capable of physical movement. All it can do is carry charge by a process of chemically modulated action potential building, yet also needs to have a means to carry out adjusting it's environment which coincidentally, tends to be filled with ions. Ions + coordinated patterns of charge propagation creates effective pumping infrastructure capable of creating overall fluid movement without the help of direct cardiovascular pressure, which can also facilitate the movement of non-charged molecules given sufficient ionic movement to disturb the neutral medium. However, this coordinated firing pattern to create overall ion flow isn't "information encoding to the cognitive process at hand" per se. It's just a bunch of cells getting fluid to move to get waste products to another location to get handled. None of those "knows" anything more than it's immediate environs, but based on things like quorum signalling in biofilms, it isn't outside the realm of possibility, that neural tissue has a completely chemically mediated process by which it knows "gradient blah can be shifted if everyone around me fires", and that given sufficient time and scope, you get an emergent quorum signalling based metabolic progress that selectively induces "coordinated garbage" from the information processing point of view, but very much not biologically/physically garbage point of view, in that that firing pattern clears the chalkboard so to speak for further processing.
So to answer your question: why do nerves seemingly need to stop what we want them to do (full time cogitation as directed by an emergent consciousness that their physical processes collectively facilitates)? The answer comes down to homeostatic maintenance, and work the tissue has to do because that's how it evolved. You use the same bunch of neurons, they fill the immediate space with metabolic waste products which makes further firing or usage more difficult until the waste products can be cleared. How do you clear them? Stop doing what you're doing & ion pumpas a group. Coordinated ion pumping isn't driving the pattern recognition/consciousness engine in ways that make any sense, it's just cycling fluid to refresh the operating environment to restore the substrate for unburdened cognition again.
Eukaryotic organisms are hard, maddeningly complex, and contain an astonishing amount of detail for something that for whatever reason, usually just seems to work. Could write volumes on these things for how deep the rabbit holes go.
usernametaken29 1 days ago [-]
> untangle what he calls the sleep paradox: Sleep is critical to human functioning, and yet, we sleep fewer total hours than any other ape
Instead of going to Tanzania you could’ve asked a sleep scientist. Sleep length has no known correlation to brain size and is known for drastic within family variation. What’s more sleep has a high within species variation too, some sleepers can survive 4 hours, others need 8. Collectively we used to sleep 9 hours in the 20th century, but it appears shorter sleep is fine too.
TLDR: no one has any idea why sleep length varies and he won’t find his answers in antrophological studies in Tanzania, though luck, buddy
sd9 23 hours ago [-]
How do you think sleep scientists got their data in the first place? Some of them went to Tanzania.
Rendered at 09:45:34 GMT+0000 (Coordinated Universal Time) with Vercel.
This feels like the key point to me. These societies follow their body and go to sleep when they are tried, while us in the west have to sleep at a specific time to fit our schedules.
This does seem to work great at group level. Considering we're in a competitive setup and all that.
I also recognize I personally benefit from others having this schedule. It would quickly go sideways if the firefighter felt like he wanted to sleep a bit more, or the police officer didn't really feel like it whenever is an emergency.
https://www.sciencedirect.com/science/article/pii/S138994572...
Does that have stronger historical backing?
Roger Ekirch’s theory, meanwhile, is based on what one could call a biased interpretation of a hand-picked selection of ambiguous sources.
Point being, if one slept for 4-5 hours, wake up for a similar chunk, and slept the same amount again, then that'd be a great way to pass the time one could likely not use to do outdoor labor.
I found this reassuring and slightly amazing, that he is wired to do his part as a nighttime lookout.
That doesn't mean they didn't sleep all night, typically.
This is a common, but poor framing of evolution. Remember: the only real rule with evolution is "did this evolutionary change mean they survived / reproduced more"? Evolution is not a local or global maxima solving function. I find this kind of attempt at interpreting selection common with engineers, programmers, etc.
So in that sense, a global maxima (minima?) solving function will probably not arrive at what we have, it has to take into account our evolutionary path, in its entirety (as in the whole tree.), because it is all encoded in 1 (or several) long molecules, and a radical changes would take a rewrite of many parts at the same time, which just does not happen. Maybe at some point we can do it ourselves... though I imagine there being a lot of unintended consequences in other places in the body :).
Another example is that sometimes complexity in a cell signalling cascade is simply there to get some timing right (ie delay some response), and the complexity is just there, and won't simplify by itself -> But then later the complexity may start to serve some purpose. Just like proteins that are "copypasta-ed" in the genome, leaving one copy free to mutate and attain a function, or not... etc etc.
https://futurism.com/evolutianary-proof-the-recurrent-laryng...
I did not know human urinary tract was suboptimal.
Are there examples of "discontinuous" evolution where a chance mutation stumbled upon a much better way to do something that allowed a species to jump the gap?
I imagine it would be very rare because chance mutations in a single individual that confer extraordinary survival / mating advantage to offset entire population would be rare like being a superman among men.
-> This also depends on population size, if there is a bottleneck event (ie 99.99 percent of some species dying) then among the 100's of survivors perhaps there could be a superman. Either because this person got lucky, or the rest got unlucky. But in general the distribution of traits is quite continuous, given large populations.
It's also good to keep in mind that us biologists have messy definitions, ie we call specimen A and B the same species when they produce fertile offspring. Some species produce offspring but infertile (Horse-Donkey, Lion-Tiger). But what if A and B have fertile offspring and B and C do, but A and C do not? The whole definition of species falls apart (it leads to a paradox).
We have a lot of that in biology. You need to learn to deal with it (sunglasses dropping down), and assign uncertainties to terms you learn about, they are often just our attempts to name boxes on continuous, multidimensional scales.
As for "discontinuous evolution"... Again, what is discontinuous? I'm sure there are events to be found of which the probability of them occurring is so small and the effects so large that they'd fall into someone's definition of "discontinuous". But I think there is by definition no such thing as discontinuous evolution. If it occurred, it had a non-0 probability of occurring, then again, maybe the universe is infinite and everything has a non-zero probability of occurring. This is getting philosophical haha. Maybe listen to some Mindscape podcasts (Sean Caroll).
Actually rabbits eat their excrement again. That's also probably not how an engineer would make it (or an intelligent designer would design it, since we seems to be going in that direction ;) ).
But you were probably asking for multicellular eukaryote organism; you may be interested in the concept of saltation https://en.wikipedia.org/wiki/Saltation_(biology) . Behind the concept of the thing itself it's interesting to think about the mechanism behind it. Regular evolution is gradual (point mutation leads to a maybe slightly different protein, which has only a relatively small scale effect but you gain or lose function over many generation), but for a saltatory evolution you most probably need radical changes in the DNA, like duplication (of a single gene, multiple gene or whole chromosome), horizontal exchanges, etc.
It's possible in plant but in animal more often than not it's not beneficial at all to have such event. Famously if you have an extra chromosome nr. 21 you get Down syndrome.
a suboptimal trait evolving that still provided an overall population benefit (via survival or reproduction) with further improvement close to impossible without a multitude of large changes is literally just a local maximum in that high dimensional space that maps traits to whatever success metric you're measuring.
the infinite wall you describe is not a wall in that space. actually I originally wrote its more like a wall in the derivative space but its not quite right either, those just point straight down from the maximum.
Edit, thanx for the addition. Perhaps my issues with looking at it as "local maxima in high dimensional spaces" (even though we think of minima usually, as in a marble will find the minimum in a landscape with gravity pointing down, sorry I'm a biologist) is that with every mutation and every change in environment the landscape changes (so basically with time), is it still a useful way to think about it like that, at that point? So it not a "landscape in a high dimensional space", but rather a "high dimensional dynamic surface", like a sea?
So, it's a bit context dependent, and definitely dependent on other mutations that have occurred in other parts of your DNA. Most complex diseases are "polygenic", meaning it's a culmination of quite a few factors that would contribute to a specific good or bad outcome.
So, yes, it could be modeled as a sort very context dependent with a lot of highly correlated non-independent covariates. We do use quite a lot of statistical and ML methods to understand the genome (I work in statistical genetics), but the complexity of biology has so far proved a tough nut to crack.
Survival rate/reproduction rate/rate of genes being spread?
see thrify gene hypothesis; I know it's not a good explanatory theory but it's a good illustration of my point
You're just renaming the terms. More/less is a fitness gradient, and the thing that lives there is called an optimizer.
Evolution is a tunable-scale optimizer. It's not perfectly local, because it shotguns to avoid local optima on a (bumpy/noisy) fitness landscape. If you tune the 'shot pattern' really wide (infinite copies with infinite variation), you'd genuinely get a one-shot global optimizer at the limit. But that's not efficient nor realistic, so typically it's somewhere in between.
Uh, compare maze solvers: you've got your greedy direct route (gets stuck in the first corner) , Dijkstra (finds all the answers but takes ages), and then stuff like A*, which is a happy medium. Evolutionary algos can be used to solve mazes just the same. I think it's a bit heavier on resources than A*, but well suited to embarrassingly parallel optimization.
edit: Heh, I actually had claude build a comparative simulation. Turns out evolution is actually very slow on a single optimization axis, and gets stumped in mazes where the detour length is greater than the "temperature"/"spread"/"noise". The actual performance metrics are fascinating. But once tuned, it is able to solve mazes. Thus an optimizer. QED :-P
I'm instantly skeptical of anyone making universal statements like this, because they're certainly not true for everyone, and having looked into these and similar (f/x "ideal room/office temperature"), are based on many entangled assumptions. Most of the time I expect it's just people making after-the-fact justification for doing (or imposing) what they most prefer.
I have no idea if that was actually done here but that’s usually how these statements are justified.
Of course we are all individuals so it may not apply to everyone but you can say that for everything in medicine. Only thing we can do is look for statistically significant differences between groups in double blind controlled studies after controlling for all other factors.
also do you know that the body temperature decreases during sleep? based on that I simply deduce and assume the more the difference between body and room temperature the more side effects arises for sleep, of course simplifying without ignoring all the rest.
As I imagine the curve, I use a real bathtub. Where is the water deepest? At the drain, which is typically just under the faucet. Where is the optimal place to sit? Well, pretty much anywhere except there, because "deepest" (an optimum) isn't enough to accurately gauge "best place". But even if you can swing the faucet out of the way... where is the optimal place? Anywhere on the bottom, a broad, slow curve, as opposed to the steep walls or rim.
So, if 18 degrees C is the optimum, what's the standard deviation? I bet it's not 0.1 degrees. Could be 2 degrees - and that would mean concentrating on 18 degrees is a distraction, not a goal.
This is something evolutionary discussions don't address well, either. If a gene line (species) has a pressure to change, it can "settle" for any place on the bathtub floor (when the solution is shaped like that). This is another example of evolution not seeking an optimum; merely avoiding a pessimum (a word I just googled, and like!).
In fact, it doesn't even matter if it's a bathtub curve. Maybe it's a slope, like the amount of capsaicin a pepper plant carries to fight off fungus. More better - but it costs something to make, so just make enough to ensure survival. More fungus? Increase capsaicin production. There's no floor to this bathtub; it's a linear slant all the way down to maximum possible capsaicin content (which, amazingly, is about 10% by weight of the fruit cells!!!).
Best sleep from my experience? It's usually about 5C at the thermostat, which is farthest from the window, by the time I wake up. And that's likely because it's in the basement, which is a typical NA basement, so you have the uninsulated and below the frost line basement wall there. The cold air coming in will be 0C and colder and I sleep next to the window. Winter is my happy sleep time.
And there are huge swaths of the world where the temperature basically never gets that low (18 C is the lowest temperature ever recorded in Kingston, Jamaica; 16 along the coast of west Africa, 18.9 in Jakarta). Even here in the southeastern US it is normal for temperatures to stay above 20 C at all times for three full months of the year (late June through early September).
Nothing wrong with liking to sleep in cold air, but it’s a preference.
I can be, actually want to be toasty warm under the blanket. But I want the air I am breathing to be fresh and cold. That is when I feel comfortable and "at peace".
I will often stick out my feet from under the blanket because it's way too toasty but the rest of my body needs to be warm.
Sure, when it's 25C I'll essentially just lay there without anything but a sheet across the chest to "feel safe" but anything else will just make me way too warm and the air I'm breathing will feel restricting.
What is really great in 25C+ temps is to be outside in a hammock without an underquilt, which cools things down considerably. But I've also slept comfortably at 0F (-18C) in a hammock. With two underquilts and a 0F sleeping bag as well as a winter tarp with doors and snow cover all around, weighing down the tarp sides (wind does suck at that temp ;)).
For you, and that's kind of my point. For me, my preferred temperature would be about 28C with no blanket or a light sheet. Something like 18C can be tolerable with blankets for me, but it's certainly not "maximum comfort", even with blankets. There is too much variation and too many things that wouldn't be controlled for, like number/thickness of coverings, and other such things. Having some "best" universal temperature is just not something generalizable like this.
Then its good night, Irene
And why wouldn't they? This is (presumably) the only kind of sleep they know.
Even in your example, you propose an individual could know multiple kinds of after-sleep feelings.
Also, we humans can get used to a lot of things and just be okay with it. For an extreme example, look at domestic abuse victims...
Like, it seems obvious to me that sleep has a higher opportunity cost in humans than most other animals. So naturally there's more evolutionary pressure in humans to sleep more efficiently.
Is this actually true? Dunno! But it was really weird that it doesn't get brought up.
Nothing surprising here. We sleep in cozy comfortable beds in a locked and secure location. Of course we'd can get int REM sleep. Compare to other primates who sleep outside with the critters and predators, deep sleep could mean the end of them.
1: https://www.healthline.com/health/how-much-deep-sleep-do-you... 2: https://www.health.harvard.edu/healthy-aging-and-longevity/r... 3: https://www.sleepfoundation.org/stages-of-sleep/rem-sleep
Where the sun doesn't go down every single day anyhow, and you may need to trudge across the tundra routinely for more than 24 hours at a stretch to get almost anywhere, without ever worrying about it at all.
Then they later came down and intermixed with (not) everyone else, so you never know who is going to be less tired than "normal" when they work a 36-hour day.
Really? My instinctive reaction to this statement is that it's quackery. Would be very interested to see headlines appear about this if it's true.
From my tissue engineering class in undergrad my 2 cents is this is maybe 95% supplements quackery and 5% genuine mystery. You can find papers that claim EM fields have cellular interactions [1]. I don't think serious scientists will touch conventional earthing, though.
[0]: https://en.wikipedia.org/wiki/Energy_medicine#Earthing
[1]: https://pubmed.ncbi.nlm.nih.gov/38068954/
So colour me skeptical of this claim as well.
And while I like going barefoot for other reasons, I don't think it makes much of a difference to the magnetic fields.
It's not really the same thing. Construction and especially the high content of charged metal (whether it's power conduits or plain old frame) may make a considerable difference.
What about the metal frame of a bed?
That may make a considerable difference.
And I may be a 10,000 year-old alien.
That would be so disappointing, I've been picturing you as Mickey's assistant in Fantasia :)
Then again, maybe that checks?
on the other side, do you know we have polarized and non-polarized cells? do you know they can be affected by electromagnetism?
this two things already establish the existence of a relationship and effects between them. If we then consider that cells mechanism work based on differential of electrical or chemical potentials, and that they continuously use that for their functions, reactions or environmental compensations well...
I just think they are related and we need to understand better.
https://news.ycombinator.com/item?id=49360307
even mechanical of course :)
https://www.pbs.org/newshour/science/dogs-poop-in-alignment-...
but then again maybe not
https://www.sciencedirect.com/science/article/abs/pii/S15587...
Some animals - migrating birds, notably - can detect magnetic fields. IIRC, sharks have close-range magnetic sensors in their gumlines.
But these are extremely rare and niche adaptations to difficult problems.
This could explain why I feel more rested when I wake up if I take glycine before going to bed, even though I don't sleep more.
while I understand might be a more known thing, it was surprising to try it and feel very rested after that. I'm still surprised and I wonder why not the whole world does it.
of course without the music at the stops would not be possible :P
> humans are weird outliers—we’re the shortest sleeping primates, yet we pack in the most REM sleep relative to this short duration
Isn't that sort of the point? Sleep is a detrimental necessity and the more efficient an organism is in needing less of it, the more effective it can be because it simply has more time to get ahead of the others?
It's still very odd that no species has ended up evolving a continuous maintenance system that can run while conscious, the benefits when hunting other animals that need sleep would be enormous, so there has to be significant evolutionary push for it. I suppose the single hemisphere sleep some marine mammals do is part of the way there, but it is at most a lazy workaround. Practically all other organs have evolved to run 24/7 for up to a century without a single break, what makes brains so universally different?
- will gains of 24/7 hunting/foraging offset the extra energy costs? Lions sleep 16-20 hours a day, according to the internet.
- do continuous maintenance systems imply duplicate systems? If so, I have a hunch that even a mere 40% increase in energy expenditure would quickly undo the gains in waking hours.
I disagree. Endurance hunters walk an animal down throughout a single day. Sleep isn't the bottleneck. Efficient bipedalism and sweat are enough.
Form is shaped by function. The liver/pancreas are designed to handle the production of detoxifying/neutralizing agents that may in and of themselves kill nearby tissue, resulting in the propensity for notable regenerative capabilities. Kidneys/intestines are high surface area to provide more room for the physical processes driving selective permeability to occur, as well as habitable spaces for beneficial microbial symbiotes that aid in digestion. Skeletal/smooth cardiac muscles are optimized for energy burning to facilitate movement. Tendons/cartilaginous membranes are optimized for lubricating joints/connective tissue purposes. Tissues like the thalamus and tonsils, are there for immunity modulation and detection. Neural tissue however is all about signal propagation, and creating shifting networks of continuity that encode information and patterns, the tissue itself is just the medium, and that medium requires some process to clean out or reset the gradients in the synaptic gap. Otherwise, electrical charges cannot be consistently conveyed as flows of ions, actuated by releases of neurotransmitters into the bridge of the synaptic gap. The other constraint unique to neural tissue as well is it isn't motile, or capable of physical movement. All it can do is carry charge by a process of chemically modulated action potential building, yet also needs to have a means to carry out adjusting it's environment which coincidentally, tends to be filled with ions. Ions + coordinated patterns of charge propagation creates effective pumping infrastructure capable of creating overall fluid movement without the help of direct cardiovascular pressure, which can also facilitate the movement of non-charged molecules given sufficient ionic movement to disturb the neutral medium. However, this coordinated firing pattern to create overall ion flow isn't "information encoding to the cognitive process at hand" per se. It's just a bunch of cells getting fluid to move to get waste products to another location to get handled. None of those "knows" anything more than it's immediate environs, but based on things like quorum signalling in biofilms, it isn't outside the realm of possibility, that neural tissue has a completely chemically mediated process by which it knows "gradient blah can be shifted if everyone around me fires", and that given sufficient time and scope, you get an emergent quorum signalling based metabolic progress that selectively induces "coordinated garbage" from the information processing point of view, but very much not biologically/physically garbage point of view, in that that firing pattern clears the chalkboard so to speak for further processing.
So to answer your question: why do nerves seemingly need to stop what we want them to do (full time cogitation as directed by an emergent consciousness that their physical processes collectively facilitates)? The answer comes down to homeostatic maintenance, and work the tissue has to do because that's how it evolved. You use the same bunch of neurons, they fill the immediate space with metabolic waste products which makes further firing or usage more difficult until the waste products can be cleared. How do you clear them? Stop doing what you're doing & ion pumpas a group. Coordinated ion pumping isn't driving the pattern recognition/consciousness engine in ways that make any sense, it's just cycling fluid to refresh the operating environment to restore the substrate for unburdened cognition again.
Eukaryotic organisms are hard, maddeningly complex, and contain an astonishing amount of detail for something that for whatever reason, usually just seems to work. Could write volumes on these things for how deep the rabbit holes go.
Instead of going to Tanzania you could’ve asked a sleep scientist. Sleep length has no known correlation to brain size and is known for drastic within family variation. What’s more sleep has a high within species variation too, some sleepers can survive 4 hours, others need 8. Collectively we used to sleep 9 hours in the 20th century, but it appears shorter sleep is fine too. TLDR: no one has any idea why sleep length varies and he won’t find his answers in antrophological studies in Tanzania, though luck, buddy