Water is blue.
What? No. As was known by Homer already, water is wine-coloured: https://en.wikipedia.org/wiki/Wine-dark_sea_(Homer)
Yeah, that's what I said, wine-blue.
Ask HN: Teach me something new
521–530 of 782 posts
Re: Ask HN: Teach me something new
#522I 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…
Ever since I learned that the frequency ratio between adjacent keys on a piano is always a constant twelfth root of 2 regardless of whether you're going black-white or white-white, I've been sort of frustrated with the way pianos are designed. Transposing a song to a different key could have been effortless if keys were structured differently, such as with uniformly alternating white and black keys, rather than the 2…
Aside from the Janko keyboard, there are instruments with the ‘harmonic table’ layout—a honeycomb of hexagonal keys: https://en.wikipedia.org/wiki/Harmonic_table_note_layout
The general principle is called ‘isomorphic keyboard’: https://en.m.wikipedia.org/wiki/Isomorphic_keyboard
Re: Ask HN: Teach me something new
#523The command 'w' on a Linux box shows uptime, load, and who's logged in.
Works on MacOS too
Re: Ask HN: Teach me something new
#524Earlier quoted context omitted.
Ever since I learned that the frequency ratio between adjacent keys on a piano is always a constant twelfth root of 2 regardless of whether you're going black-white or white-white, I've been sort of frustrated with the way pianos are designed. Transposing a song to a different key could have been effortless if keys were structured differently, such as with uniformly alternating white and black keys, rather than the 2…
It is so annoying that standard guitar tuning isn't all perfect fourths and we've decided to throw in a major third between the G-B strings. Bar chords be damned, I want to be able to visualize it symmetrically and have chord shapes that work the same across the fretboard.
You might like the Linnstrument:
https://www.rogerlinndesign.com/linnstrument
As a longtime guitarist myself, I found it quite easy to learn.
You can think of each row as a guitar string. In the default setup, each row is a perfect fourth above the row below. The green lights are the white keys on a piano; the unlighted keys are the black ones. The blue lights are C natural.
Skip a square diagonally up and to the right for an octave.
Chord shapes are uniform across the whole surface.
Keys are sensitive to pressure, left-right movement, and top-bottom movement. In the default configuration, rocking left and right yields vibrato and moving top-bottom controls some other MIDI parameter (usually filter cutoff, but it's configurable).
Sliding finger pressure to different keys to the right and left gives portamento. Sliding to the next row up or down gives legato.
Once you get used to these parameters, it becomes super expressive.
It's a MIDI controller, not a complete instrument, so you need a MIDI-controllable source of sounds. It's an MPE instrument, so, if you want the full experience, you want some kind of MPE-capable source of sounds (MPE is "MIDI Polyphonic Expression", and it means that multiple MIDI channels are dedicated to the instrument in order to give full, separate expression to each of several voices). MPE is a relatively new MIDI development that is not supported everywhere yet, so you have to pay attention to which sound devices support it if you want the full experience.
I have one; it's my favorite electronic instrument that I've ever tried. I also have an Eigenharp Pico, and I like it, but I like the Linnstrument better. (It doesn't look as cool as an Eigenharp, though :-).
When I decided to get one, I discovered that they're a bit hard to buy. Not very many places have them, and when I was looking, even Roger Linn didn't have any available. I eventually found one for list price at Detroit Modular (https://www.detroitmodular.com/).
Re: Ask HN: Teach me something new
#525Earlier quoted context omitted.
Thanks for this! As a French, I always wondered why this oddity. That should also be introduced when teachers explain hexadecimal :-)
Me too! Btw, in the spirit of the title of this thread, in English you would say "as a French person". In the past, "Frenchman" was used but it's understandably out of favour these days. "French" can be used as an adjective but not a noun in this context. It's a very common error, I suppose since "français" can be used as an adjective or a noun en français :)
And don't forget french as a verb! -said every high school guy ever
Re: Ask HN: Teach me something new
#526Earlier quoted context omitted.
There is a book from the 80ies/early 90ies "POWERS OF TEN: About the Relative Size of Things in the Universe" by Philip & Phylis Morrison. That is exactly that.
It was also a 1977 short film: https://www.youtube.com/watch?v=0fKBhvDjuy0
I suspect that Marshall McLuhan loved this film.
Re: Ask HN: Teach me something new
#527Humans might just be the stupidest animals on the planet when it comes to seasonal migration, we get tied down by our monetary system, taxes, government policies, borders, etc., while polluting our planet with patchwork solutions like air conditioning for the summer or burning fossil fuels to heat our surroundings in the winter. We can't simply just "move" to a different location like other animals.
Many older/retired Canadians migrate every winter; they're colloquially known as "snowbirds". Ontarians head to Florida, BCers head to Arizona.
Re: Ask HN: Teach me something new
#528I'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…
It's fascinating that you were still able to read without seeing! I've had migraines about every two months for the past 12 years, and with very few exceptions they've always followed the same pattern: 30 minutes of scotoma (small to large to small), 30 minutes of peace, then a strong headache for about an hour. I usually still have a mild headache the next day.
I've had the migraines mostly while sitting an the computer or reading, but it seemed impossible to me to continue to read since the zig zags were right above the letters, and frankly quite distracting. Because of that, I've never really tried to continue.
It seems weird to say that, but I'm almost looking forward to the next migraine solely to test if I can still read if I really try. That would be awesome! Thank you for your description!
Re: Ask HN: Teach me something new
#529Harmonicas are amazing instruments. At first people assume them to be like toys (you can buy really cheap ones everywhere) and initially the concept seems really easy: 10 holes, drawing air produces some notes and blowing air produces other notes. But the more you get into it, the more amazing it gets. Soon you discover that you can bend notes by positioning your tongue in a specific way and your repertoire increases…
After reading your comment and its replies, I went looking on Youtube for some harmonica videos.
I don't play the harmonica, and I don't have any idea about music. However, I do like the harmonica as an instrument whenever I hear it in some songs.
I find that usually the harmonica always plays multiple notes together, and to my untrained ears, this always makes me feel that it can never hold the stage like maybe, a saxophone can.
Then I came across the video below, and honestly, I was extremely impressed. It felt as if each note was being played by itself and the artist had complete control over the instrument.
https://www.youtube.com/watch?v=uIss2Qmmc5k
Editing to add:
The artist, Indiara Sfair, also has a complete course on her website.
Re: Ask HN: Teach me something new
#530The 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…
Well then it’s equally likely that badgers the size of Earth could be forming from time to time, and since they’re the size of earth they would decay much more slowly than our puny local badgers… so shouldn’t we see the occasional Earth-sized badger through the Hubble? Or how about the much lower odds needed for a copy of Shakespeare’s plays translated to Klingon inscribed on a giant sheet of titanium to appear spont…
If by "equally likely" you mean "much, much less likely, but also more than 0 probability" than yes.
> so shouldn’t we see the occasional Earth-sized badger through the Hubble?
Take another look at the time-frame on the GP's comment and remember that the Universe is ~10^13 years old.