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Ask HN: Teach me something new

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Re: Ask HN: Teach me something new

#661

Post by mikelevins »

MmdYw wrote: post #587
mikelevins wrote: post #28

I've described this on HN before; forgive me if you've already seen it. I have chronic migraine. It sounds worse than it is; I rarely suffer attacks anymore, and when I do, they're usually mostly harmless, as in the case I'll describe below. Contrary to popular belief, migraine is not a headache. It's something a little more like an epileptic seizure. Intense headaches are one common symptom, but there are a lot of o…

wow you had described so well. Curious, what is the book? wondering if that is the confounding variable

Disappointingly, I don't remember the book for sure. I think it might have been one of the volumes of Gene Wolfe's Book of the New Sun, which I re-read from time to time for pure pleasure.

Re: Ask HN: Teach me something new

#662

Post by mikelevins »

alar44 wrote: post #634
mikelevins wrote: post #428

Earlier quoted context omitted.

I can't say that I agree. I got pretty thoroughly familiar with several psychedelics in the late 70s and early 80s, and although I value those experiences to this day, they didn't teach me anything especially relevant to the scotoma or sleep/wake experiences I've reported.

Interesting. In my experience, I end up cleaning my house the next day, because I noticed that the light switch in my room isn't just a light switch, it's a dirty light switch. I'll see stains or smudges that I never noticed. Suddenly there are tons of details that I can see that just got smeared in "normal" waking life.

Well, I noticed a bunch of things during and after tripping, and some of it was even true, but I didn't ever notice that seeing and being aware of seeing were two separate and separable processes, and I didnt ever notice that I could be awake and asleep at the same time, not until the events I recounted here, both of which occurred years after I had, as they say, gotten the psychedelic message and then hung up the phone.

Re: Ask HN: Teach me something new

#663

Post by ozfive »

stavros wrote: post #458
elric wrote: post #275

Earlier quoted context omitted.

Story time: Back when I was in school, our introductory electronics class had us make a PCB for a PICmicro programmer on our first day. We got a handout of the schematics. We had to transfer its negative to a copper coated plate using some chemical, used UV light to fixate it, then dissolved the rest of the copper in acid. Finally we got to drill the holes for through-hole soldering points. Next class we soldered all…

I used a 3D printer to draw the schematics onto copper clad with a marker: https://www.stavros.io/posts/make-pcbs-at-home/

Check out this company if you haven't already heard of them! Nano-dimension https://www.nano-di.com/

Re: Ask HN: Teach me something new

#664

Post by claylimo »

mikelevins wrote: post #406
claylimo wrote: post #83

Earlier quoted context omitted.

Being aware while asleep is something that can happen to advanced meditators. The more aware you are the more you are there is no difference between being awake or asleep. I haven’t heard it brought up in any other contexts except maybe for lucid dream practitioners. I’ve also read accounts from those who have done dark room retreats where perception of being awake and asleep blur and the perception of what you are e…

I went to school at Naropa University, where a lot of meditation was part of the required curriculum (at least, when I was there; I have no idea what it's like now). I never experience the awake/asleep thing in connection with meditation, either at Naropa or in meditation practice outside the school, but I doubt that I could be in any way considered an advanced meditator.

Should be clear: not every advanced meditator experiences this and is not a prerequisite to be “advanced”. It would just not be unusual if it did happen.

Re: Ask HN: Teach me something new

#665

Post by bsmith »

snyena wrote: post #38

The Boltzmann brain hypothesis suggests that it would be more likely for a single brain to spontaneously and briefly form in a void (complete with a memory of having existed in our universe) rather than for the universe to come about in the manner cosmologists think it actually did. In this physics thought experiment, a Boltzmann brain is a fully formed brain, complete with memories of a full human life in our univer…

Oh no, not again.

Re: Ask HN: Teach me something new

#666

Post by Beldin »

sbergjohansen wrote: post #293
hiisukun wrote: post #123

In a lot of terminals, Alt+. (or Option+. on Mac) will paste in the last argument of the previous command. $ mkdir hi $ cd You can hit . several times to cycle through earlier final args.

!! substitutes the last command: sudo !! and cd - takes you to the previous directory.

!$ substitutes the last command's arguments, if memory serves.

Re: Ask HN: Teach me something new

#667

Post by andbberger »

kaba0 wrote: post #651
andbberger wrote: post #641

Earlier quoted context omitted.

> The axons are just as important as the neurons. what. an axon is a component of a neuron are you referring to glia?

No, I meant to highlight that “most neurons are here” may not be the important question to ask, but their interconnectedness which is achieved through axons, and which gives the most volume of the brainz

indeed the focus of most research is the neuropils

Re: Ask HN: Teach me something new

#668

Post by andbberger »

SemanticStrengh wrote: post #652
andbberger wrote: post #642

Earlier quoted context omitted.

> we lack real-time datasets and we lack accurate instruments to observe and retroengineer the while system. wrong again. whole brain 2p imaging is routinely performed in c elegans ( and drosophila for that matter) for a number of years now. in fact whole brain ephys in c elegans is feasible, although it would be an experimental tour de force. c elegans does not have '~150-300 neurons', it has precisely 302, and the…

Come on, who do you think you are talking with? I have read many papers about C.elegans and my claims are backed up: "the inability to reliably identify all neurons within whole-brain recordings has precluded a full picture with circuit-level details." "we expect our work to aid in these endeavors (Bargmann and Marder, 2013; Brennan and Proekt, 2019; Kaplan et al., 2020; Kato et al., 2015). A richer set of network re…

i really couldn't care less how many papers you've read. whole brain calcium imaging is routine, no one expects it to be the whole picture. it's useful though.

and no it is not a matter of debate, there are precisely 302 neurons

Re: Ask HN: Teach me something new

#669

Post by justsomehnguy »

andrew_ wrote: post #459

When ever drilling or hole-cutting into fiberglass, always use masking tape generously applied over and around the area being cut into. Run drill bits in reverse to get past any gelcoat or paint coatings, then run the drill forward to affect the cut. The same goes for hole saws. Slow speed is best with the proper blade for jigsaws. This will prevent cracking of coatings (especially gelcoats) and splintering of the fi…

The true TIL is always in the comments.

With a slight /s

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