Ask HN: Teach me something new • Hacker News Board

Re: Ask HN: Teach me something new

#591

Post by Kaibeezy » Sat, Apr 30, 2022, 5:05 PM UTC

SemanticStrengh wrote: post #565

Kaibeezy wrote: post #279

Earlier quoted context omitted.

I’d like a 410% reduction in all cause mortality as much as the next Joe, but the Pubmed similar articles list isn’t very encouraging. Nearly all the 90 articles listed spanning 40 years are from Russia, many from the same small group of researchers. I observe: 1) there HAS been a sustained effort and publication among a substantial group of investigators, and yet 2) these dramatic results have failed to attract furt…

Your Occam razor is a tragic self fulfilling phophethy. By people assuming scientists are not scientifically illiterate they silence those ignored potent results and dismiss them. The fact is scientists are illiterate. Russian are the world leaders in gerontology. A reason being they have a well funded longevity institute since the 90s. Contrary to the rest of the world they are not retarded and therefore do human tr…

I was applying Occam to myself as a meta-researcher (I like that term!) not to “scientists”. I will happily assume there is a wide range of literacy among scientists, and that it wouldn’t take many positive results for research on thymalin to start ringing bells. I will also admit to the assumption that Russia cannot possibly be the only place where there is a high degree of willingness to experiment aggressively with , on, or on behalf of people who are running out of time. China seems like one place. India. Indonesia. It’s very difficult to see how real progress in this field wouldn’t be publicized.

As an aside, may I suggest to you that in a forum with many Americans, use of the word “retarded” will usually get you a very strongly negative reaction and obliterate consideration of any other points you may be making.

Re: Ask HN: Teach me something new

#592

Post by mikelevins » Sat, Apr 30, 2022, 5:09 PM UTC

catsarebetter wrote: post #56

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.

There's a specific figure of speech related to this claim that kind of irks me: when someone says that they "choose to believe" something.

Really? You can choose to believe something? I'm really not sure I can. If you really think that you can, try an experiment like this:

1. Look closely at something familiar--maybe your car or your house, for example. Identify what color it is, or what colors predominate.

2. Now turn the other way so that you can't see it. Choose to believe that it's a different color.

3. Turn at look at it again. Are you surprised by what you see?

Re: Ask HN: Teach me something new

#593

Post by kaba0 » Sat, Apr 30, 2022, 5:11 PM UTC

iamacyborg wrote: post #328

d4mi3n wrote: post #136

Earlier quoted context omitted.

> also anyone know how is lymph pumped? I don't think the heart pump lymph so is it stagnant? I have a close friend who is working on getting certified as a massage therapist. Skeletal, muscular, and vascular anatomy make up a big part of the required knowledge for the certification. Two interesting things I learned from them: 1. The lymphatic system is massive and runs alongside our vascular system. For example, the…

A thing I find interesting is that autopsies are finding that folks with tattoos end up with stained lymph nodes as the tattoo ink gets spread through the lymphatic system. As tattoos have become hugely popular in the last couple decades I wonder if we’ll start seeing more health problems associated with the chemicals used in inks.

Ink is known to be found in the blood for a bit of time after the tattoo (people can’t even donate for a year after where I live?).

So it is not that surprising to find it in lymph nodes whose very purpose is to accumulate foreign things in the body and possibly make them “meet” with immune cells. Also, tattoos are not completely static structures, they are tiny ink droplets that do get collected by our body — we are just unable to handle a certain size of them. Tatto removal works exactly by breaking up the ink to smaller pieces which our cells can handle.

Re: Ask HN: Teach me something new

#594

Post by PufPufPuf » Sat, Apr 30, 2022, 5:12 PM UTC

pards wrote: post #449

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.

Or ^r to search through the command history (bash only?): $ grep blah * $ ^r (reverse-i-search)`g': grep blah * This is far and above my most commonly used shell command

This can be made much more powerful by McFly, I recommend: https://github.com/cantino/mcfly

Re: Ask HN: Teach me something new

#595

Post by kaba0 » Sat, Apr 30, 2022, 5:13 PM UTC

SemanticStrengh wrote: post #553

leemailll wrote: post #490

Earlier quoted context omitted.

I don't know where you get the idea brain does not include cerebellum. This is completely false

Re-read my sentence, yes the cerebellum is part of the CNS and so is the spinal cord. Is the spinal cord part of the brain? Why not. What I meant is what people generally denote and imagine when we speak about the brain, is actually the cerebrum https://www.cancer.gov/publications/dictionaries/cancer-term... The cerebellum, pons, etc are distinct extensions.

The brain/spinal coord is commonly divided at the start of the brain stem. By all accounts, the cerebellum is part of the brain.

Re: Ask HN: Teach me something new

#596

Post by kaba0 » Sat, Apr 30, 2022, 5:16 PM UTC

SemanticStrengh wrote: post #179

subroutine wrote: post #173

Earlier quoted context omitted.

Here's an interesting fact about the cerebellum: it has more neurons than the rest of the brain combined, and as far as we know, all it does is help with balance a bit. There have been cases studies of people with a fully ablated cerebellum, and they can still walk, just a bit unsteadily.

> There have been cases studies of people with a fully ablated cerebellum, and they can still walk, just a bit unsteadily. ? I had heard the cerebellum is responsible for predicting the next token in a sentence (reminiscent of language models) but you're saying language is not impaired without a cerebellum?

The axons are just as important as the neurons. While neural networks are not good analogues of the real thing, one can imagine that no matter the neurons, without weights between them it would be utterly useless. The cerebrum is chock full of axons.

Re: Ask HN: Teach me something new

#597

Post by morninglight » Sat, Apr 30, 2022, 5:16 PM UTC

thinkingemote wrote: post #73

People have always and will always think that the time they are living in is the most important time ever. This is a self evident fallacy or a universal truth. These times we are living in are not the most important. Or, of they are, then everyone everywhere is at everytime living at the same importance. Now, there is something called the hinge of history that some mathematicians have looked into the chance of "well…

Everyone who ever lived thought they were in the "the most important time".

However, our generation is the first to be capable of totally destroying human civilization. That makes us somewhat special. .

Re: Ask HN: Teach me something new

#598

Post by vermarish » Sat, Apr 30, 2022, 5:19 PM UTC

someweirdperson wrote: post #319

vermarish wrote: post #225

An electric guitarist usually has a pedalboard that they use to make different guitar tones. Let's approach this like an electrical engineer might. Time is a straight arrow: call it t. The guitarist plays, and their guitar pickup records a signal. At any time t, measure the value of this signal's waveform: call it x. That signal can go into a pedal that maps each value to create an output signal. Call it f(x, t). The…

> The pedal is a time-invariant system when it satisfies f(x, t1) = f(x, t2). In English, a time-invariant pedal does not warble over time. > Reverb, delay, EQ, and wah are all LTI effects. The math doesn't work, assuming scalar f, x, t1, t2 as implied by their description. For a delay the x passed at t1 has no correlation to what f calculates to. It needs vectors F(X, t) and X I think.

You found it! I rewrote my comment like six times because I think the rigorous notation where the signal is a function of t is a little messy for a HN comment. I tried picking a notation that was less intimidating and wasn't too obviously inconsistent.

Re: Ask HN: Teach me something new

#599

Post by mikelevins » Sat, Apr 30, 2022, 5:23 PM UTC

mdp2021 wrote: post #543

mongol wrote: post #270

Earlier quoted context omitted.

I would explain it as colors are byproducts of electromagnetic frequencies, but they are qualia generated by your brain. There are many optical illusions that play with this fact. For example, in twilight, the frequencies you would call blue are different than what you call blue during daytime. This is because the brain /eye adjusts to the general light conditions. (As sunlight is generally "redder" at twilight).

Sure, but those colours still «are electromagnetic frequencies». The poster stated that some colours are not.

If the colors were the same thing as the electromagnetic frequencies, then the same electromagnetic frequencies would be the same colors, by definition.

They aren't. For example, put a card of color A in front of a background of color B; now move it in front of a different background of color C. You will experience color A as being a different color (especially if colors A, B, and C are chosen to maximze the effect).

The electromagnetic spectrum returned by card A isn't different, but the color perceived is. Thus, electromagnetic spectrum is "out there", but color is "in here".

Re: Ask HN: Teach me something new

#600

Post by possiblydrunk » Sat, Apr 30, 2022, 5:24 PM UTC

mdp2021 wrote: post #199

subb wrote: post #80

Colors don't exist outside of your brain.

Colours are, in the outside world, fuzzy ranges of electromagnetic frequencies: they do «exist outside of your brain». (Similarly, "brain" and "mind" are not the same.) Otherwise, the intended general idea is that found e.g. at the beginning of Arthur Schopenhauer's Welt als Wille und Vorstellung : > "The world is my representation": this holds true for every living, cognitive being, although only a human being can b…

The distinction between colors exists outside our brains (different frequencies of em radiation), but the color "red", for example, only exists in your brain. Heck, I have no clue what someone else perceives when I perceive "red". As long as it is stable, it doesn't matter.