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Ask HN: Teach me something new

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Re: Ask HN: Teach me something new

#321

Post by znpy »

schoen wrote: post #143
znpy wrote: post #8

afaik the only way to get epoch with only posix-compliant tools is to use awk: $ awk 'BEGIN {srand(); t = srand() ; print t}' 1651247949 explaination: 1. srand if not provided with a seed will use the current unix epoch as seed 2. srand will return its previous seed in a new initialization (and we assign it to t) 3. we print t I learned this via a "Systems we love" talk ( https://www.youtube.com/watch?v=IfhMUed9RSE )

It's definitely not POSIX, but a good GNUish way is date +%s Your portable suggestion worked in gawk, nawk, and mawk -- cool!

> Your portable suggestion worked in gawk, nawk, and mawk -- cool!

indeed, that's the cool thing about it!

Re: Ask HN: Teach me something new

#322

Post by goodpoint »

mettamage wrote: post #59

I have tinnitus. Before I had tinnitus I could simply use earplugs. Problem when I sleep: when I use earplugs it presses in my ear and it aggrevates my tinnitus. Solution: - Bose QC 35 - Earplugs Now the earplugs don't get pushed in and don't aggrevate the tinnitus. The bose QC 35 gets pushed onto whatever is directly outside your ear, which is a bit uncomfortable but fine. This is my new earplugs setup and it works.

Also: try multiple shapes and brands of earplug. People have different ear canals and the level of comfort and effectiveness changes a lot.

Re: Ask HN: Teach me something new

#323

Post by kmarc »

Aidevah wrote: post #268

One of Bach's most famous church cantatas, BWV 140[1], was written for the 27th (or no. 3^3, the importance of this will be apparent in a moment) Sunday after Trinity, the last possible Sunday before Advent. The cantata is a chorale cantata based on the Lutheran Hymn "Wachet auf, ruft uns die Stimme", the opening movement is a chorus that is based on this tune. The tune is in Bar form, the first 3 verses are repeated…

Oh he was brilliantly playful with his musical cryptograms.

Also see:

* BACH Motif: https://en.m.wikipedia.org/wiki/BACH_motif

The letters of his name, B, A, C, H encoding a melody.

Re: Ask HN: Teach me something new

#324

Post by matheusmoreira »

ToJans wrote: post #110

I watched a piano/music teaching video from the 60s yesterday that made it all "click" [1] Most modern music chords patterns are easy to find out on piano. Start on any of the white keys, and play 7 white keys left to right. That is called a mode: a series of notes separated by certain intervals to compose a song. Different modes have different vibes. Atmosphere of the song ( sad or happy) is directly correlated by h…

> Most popular songs are composed by using mostly the same repeating chord patterns

https://youtu.be/oOlDewpCfZQ

Way too many to list.

Re: Ask HN: Teach me something new

#325

Post by goodpoint »

iKevinShah wrote: post #79
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 have been some studies to prove it too right? I dont remember exactly.

Yes, indicating that our consciousness is simply reacting to our choices and rationalizing them rather than making them in the first place.

Re: Ask HN: Teach me something new

#327

Post by kmarc »

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.

More precisely, this is not a feature of the terminals but of readline.

https://www.man7.org/linux/man-pages/man3/readline.3.html

All engineers working with the command line (even after 35 years) really, really should open and read

    man bash
and

    man readline

Re: Ask HN: Teach me something new

#328

Post by iamacyborg »

d4mi3n wrote: post #136
SemanticStrengh wrote: post #122

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…

> 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.

Re: Ask HN: Teach me something new

#329

Post by femto »

SemanticStrengh wrote: post #122

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…

The brain's lymphatic system was confirmed to exist only recently, in 2017.

https://www.theatlantic.com/health/archive/2017/10/scientist...

https://www.sciencedaily.com/releases/2019/07/190724133649.h...

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