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Ask HN: Teach me something new

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151–160 of 782 posts

Re: Ask HN: Teach me something new

#151
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…

> Like any brain in such circumstances (the hostile vacuum of space with no blood supply or body), it would almost immediately stop functioning and begin to deteriorate.

that is not such rare fluctuations are ephemeral. they are ephemeral because the dynamical system is reversible, for the same reason that the molecules in a box of gas dissipate immediately after they happen to coalesce in the corner

Re: Ask HN: Teach me something new

#152

I'm going to go a bit random...get a styptic pencil! Nobody I've met even knows what they are. I came across them years ago in the shaving section, and was blown away by their utility. They are solid pieces of some saltlike material that are super effective at stopping bleeding. We don't even have bandaids in our house anymore, the pencils are way more useful.

Proraso anti-bleeding gel is the best thing I have found for razor cuts. It dries into a transparent artificial scab.

Re: Ask HN: Teach me something new

#153
post #132

In the 1800s, scholars who knew a lot of languages (including, often, several modern and ancient European languages, and increasingly also Sanskrit) started to notice some amazing patterns about similarities in words among all of these languages, including languages from very far apart and that had no visible connection at all from the point of view of their present-day speakers. As these patterns were explored, they…

The book "The Unfolding of Language: the evolution of mankind's greatest invention" by Guy Deutscher explains this very well and has numerous examples. As a language noob, I found it fascinating!

Re: Ask HN: Teach me something new

#154

Most of the scientific problems (diseases, quantum gravity, etc) have been resolved, it's just that no one knows it. Because researchers are paid to produce new papers, but nobody is paid to extensively read the ocean of existing papers. Cancer? PNC-27 + thymalin Ageing? Skq1 + Epitalon Quantum gravity? https://arxiv.org/pdf/gr-qc/9706055.pdf

Isn't that what conferences and journals are for? Reviewing and selecting the most important papers?

When something is really solved (a solution exists without negative side-effects; and this fact has been verified several times), they should indeed look for new problems.

Re: Ask HN: Teach me something new

#155

Very few people know the potent facts about the brain: * your neurons are not in your "brain" 90% of your neurons are not in what you generally denote by brain. They are in your cerebellum. The cerebellum has a distinct neural architecture, that difference is in fact clearly visible with the najed eye. A very poor simplistification would be to call it our GPU. * the spinal cord is huge and is structurally a contiguou…

this is a terrible list of 'brain facts'. they're not interesting or constructive to a larger understanding, and analogizing the cerebellum to a GPU is naive and misleading to the point of being insulting. working neuroscientist don't think about consciousness, we look at neurobiology, develop experimental techniques to allow imaging of ever larger numbers of neurons, try to understand how the brain computes. I don't…

What an absurd dismissal. > they're not interesting

You have a failure of appreciation, yet those facts are potent and surprising.

>constructive to a larger understanding

Yes they are not, who cares? Teaching neuroscience is of course a non-goal of my comment, what an irrelevant thing to say..

>analogizing the cerebellum to a GPU is naive and misleading to the point of being insulting.

Exactly, but if you had allocated a few neurons while reading my comment you would have seen I said "a poor simplist-ification" akin to only transmitting the idea that it is the place in the brain with the most compute power/parallelism.

>working neuroscientist don't think about consciousness, we look at neurobiology,

Such a useless thing to say. It is a truism that scientists mostly focus on what can be studied by the means of metrology/empiricism and indeed for now, qualias are low-studiable. Saying this has no more value than saying water is wet.

Your shallow dismissal is just a pretext to your layman explanation of what is the brain. Explanation with btw zero level of detail. I have read over 1000 papers in neuropharmacology and there are in facts a lot of things we understand about brains. But, the C.elegans ~150-300 neurons, which is much simpler than the fruit flies, is as of now unexplained in terms of neural code, despite having an almost complete connectome of its neuroreceptors. But no the C.elgans is not one of the most complex thing in the universe. This is a fallacy that make seems progress seems impossible. The truth is, C.elgans has a relatively reasonable complexity, however we lack real-time datasets and we lack accurate instruments to observe and retroengineer the while system.

Re: Ask HN: Teach me something new

#157

Double-clicking on text selects the whole word. Double-clicking and dragging selects text word-by-word. Triple-clicking selects the whole paragraph. Middle-clicking a link opens it in a new tab. Middle-clicking a tab closes it. Middle-clicking in general often has useful functionality!

And X11 on Linux (if you're not using Wayland) supports middle-click emulation, where pressing the left and right mouse buttons simultaneously (debounced to within a couple milliseconds) will be interpreted as a middle-click.

I may or may not use this with my laptop dozens of times a day (it's how I copy/paste out of xterm).

(Fun bit of trivia, my old EliteBook 8470p has a trackpad+trackpoint setup with two independent sets of buttons, and while I don't seem to be able to middle-click with the trackpoint buttons, I can send a middle-click by pressing both trackpad buttons, keep them held down, and then independently send left and right clicks (press-release) using the trackpoint buttons as much as I want. I somehow doubt that was an accident. Engineering archaeology is fun :D)

Re: Ask HN: Teach me something new

#158
post #119

In drug development, a lot of the engineering goes into making sure the pharmaceutical compound -- having been developed -- actually reaches the target area of the body. If the compound is a relatively large particle that needs to get into the blood stream, a nasal spray might result in the compound being deposited at the bottom of a person's lungs without ever getting absorbed. If stomach acids break the chemical do…

> a nasal spray might result in the compound being deposited at the bottom of a person's lungs without ever getting absorbed Is it also true for cocaine and other similarly ingested substances? Are coke users walking around with garbage in their lungs?

I don't actually know the answer to this, but I know that heavy particles in the lungs would trigger an intense fit of coughing to get rid of them, and so I doubt that residue would accumulate. I am not a doctor and this is not medical advice.

Re: Ask HN: Teach me something new

#159

You probably don't have free will, you have no more control of the thoughts that motivate you to take action as you do the thoughts that do not.

well, I think that if you are aware (mindfulness) about your thought patterns you can steer them, and usually what you think you become, because your thoughts drive actions. In my personal experience practicing self awareness has helped with this. I understand that there are factors outside of our control, but what goes on within us can be controlled to some extent with effort and time.

You cannot control physics though. What goes on in your brain is entirely just physics.

We have a subjective impression of control, but that too is only the result of physics.

Re: Ask HN: Teach me something new

#160

Earlier quoted context omitted.

this is a terrible list of 'brain facts'. they're not interesting or constructive to a larger understanding, and analogizing the cerebellum to a GPU is naive and misleading to the point of being insulting. working neuroscientist don't think about consciousness, we look at neurobiology, develop experimental techniques to allow imaging of ever larger numbers of neurons, try to understand how the brain computes. I don't…

What an absurd dismissal. > they're not interesting You have a failure of appreciation, yet those facts are potent and surprising. >constructive to a larger understanding Yes they are not, who cares? Teaching neuroscience is of course a non-goal of my comment, what an irrelevant thing to say.. >analogizing the cerebellum to a GPU is naive and misleading to the point of being insulting. Exactly, but if you had allocat…

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