MA

@13ma1@discuss.systems
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282 Following
142 Posts
Builds / operates carrier, cloud, & enterprise networks; curious about novel approaches at scale. I enjoy learning about technology: new, current, and legacy.
Verified account (recursively!)https://discuss.systems/@13ma1

The 12th root of 2 times the 7th root of 5 is

1.333333192495....

And since the numbers 5, 7, and 12 show up in scales, this weird fact has implications for music! It leads to a remarkable meta-meta-glitch in tuning systems. Let's check it out.

Two important glitches that afflict tuning systems are the Pythagorean comma and the syntonic comma. If you go up 12 fifths, multiplying the frequency by 3/2 each time, you go up a bit less than 7 octaves. The ratio is the "Pythagorean comma":

p = 531441/524288 ≈ 1.01364326477

And if you go up four fifths, you go up a bit more than 2 octaves and a major third (which ideally has a frequency ratio of 5/4). The ratio is the "syntonic comma":

σ = 81/80 = 1.0125

In music it would be very convenient if these two glitches were the same - and sometimes musicians pretend they are. But they're not! So their ratio is a tiny meta-glitch. It's called the "schisma":

χ = p/σ = 32805/32768 ≈ 1.0011298906

and it was discovered by an advisor to the Gothic king Theodoric the Great.

In the most widely used tuning system today, a fifth is not 3/2 but slightly less: it's

2^(7/12) ≈ 1.4983070769

The ratio of 3/2 and this slightly smaller fifth is called the "grad":

γ = p^(1/12) ≈ 1.0011291504

Look! The grad is amazingly close to the schisma! They agree to 7 decimal places! Their ratio is a meta-meta-glitch called the "Kirnberger kernel":

χ/γ ≈ 1.0000007394

If you unravel the mathematical coincidence that makes this happens, you'll see it boils down to

2^(1/12) 5^(1/7) ≈ 1.333333192495

being very close to 4/3. And this coincidence let Bach's students Johann Kirnberger invent an amazing tuning system.

(1/2)

Here's a fascinating little "home movie" that #YouTube just surfaced for me. Shot as a personal walk through by the gentleman who ran Camera 4 on "The Price Is Right", it's a backstage tour the morning of the last episode of the show ever hosted by Bob Barker, in 2007.

I've told the story before of my experience with "The Price Is Right" crowd at CBS Television City in Hollywood, many years ago. I had come over to the studio to tape a network news interview.

To get from the parking area to the famous "Artists' Entrance" I had to literally push my way through a crazy crowd of people waiting outside to enter Stage 33 for the show. It was an utter madhouse. Quite an experience!

https://www.youtube.com/watch?v=q-Ypsde-L74

Bob Barker's Last Show

YouTube

I hope this beagle finds you well.

#DogsOfMastodon

Milky Way over a Turquoise Wonderland

Image Credit & Copyright: Petr Horálek / Institute of Physics in Opava, Sovena Jani

https://apod.nasa.gov/apod/ap230529.html #APOD

APOD: 2023 May 29 – Milky Way over a Turquoise Wonderland

A different astronomy and space science related image is featured each day, along with a brief explanation.

'sup lil prairie dog
Fun fact: "up" is "dn" rotated 180 degrees.
OTD 1975: First meeting of Silicon Valley's Homebrew Computer Club. Newsletters here: https://www.computerhistory.org/collections/catalog/102740021
Homebrew Computer Club newsletters | 102740021 | Computer History Museum

Watching his physics lectures on #YouTube, I really wish I could have met Richard Feynman. Theoretical physicist, recreational safe cracker, Nobel Prize winner, and bongo drums player. And an absolutely wonderful lecturer. It's so marvelous that his lectures have survived and are available on YouTube. Right now I'm watching the ones recorded at Cornell in 1964. - https://www.youtube.com/watch?v=j3mhkYbznBk
Richard Feynman - The.Character of Physical Law - Part 1 The Law of Gravitation (full version)

YouTube

Bell Telephone Launched a Mobile Phone During the 1940s: Watch Bell’s Film Showing How It Worked

https://www.openculture.com/2023/01/bell-telephone-launched-a-mobile-phone-during-the-1940s.html

Bell Telephone Launched a Mobile Phone During the 1940s: Watch Bell’s Film Showing How It Worked

Suddenly, it becomes 'important for someone to get in touch with the drivers of this outfit. How can it be done?' Any modern-day viewer would respond to this question in the same way: you just call the guys.

Open Culture

Super-nerdy #networking #books #recommendation:

The Undersea Network by Nicole Starosielski

There are other good books about network infrastructure, but the thing I found fascinating about this one is the level of #culture and #history analysis it does. It goes into detail about the impacts transpacific cables have had on the various Pacific islands they land on. Things like politics and military involvement, and local populations' inability to have a say in where the cables land (or whether they do at all). Lack of benefit to local populations (both network and economic) since frequently the cables aren't even terminated at all on these islands, they are just pass-throughs. "Cable colonies" that got established for Europeans servicing the cables to live separately from the indigenous folks. This book is full of interesting, important stuff - I highly recommend it.

Book: https://www.dukeupress.edu/the-undersea-network

Photos and maps: http://www.surfacing.in/

I almost dragged my family to see a manhole cover on Oahu thanks to this book, until I discovered what traffic on Oahu is really like.
http://www.surfacing.in/?place=makaha

Duke University Press - The Undersea Network

×

The 12th root of 2 times the 7th root of 5 is

1.333333192495....

And since the numbers 5, 7, and 12 show up in scales, this weird fact has implications for music! It leads to a remarkable meta-meta-glitch in tuning systems. Let's check it out.

Two important glitches that afflict tuning systems are the Pythagorean comma and the syntonic comma. If you go up 12 fifths, multiplying the frequency by 3/2 each time, you go up a bit less than 7 octaves. The ratio is the "Pythagorean comma":

p = 531441/524288 ≈ 1.01364326477

And if you go up four fifths, you go up a bit more than 2 octaves and a major third (which ideally has a frequency ratio of 5/4). The ratio is the "syntonic comma":

σ = 81/80 = 1.0125

In music it would be very convenient if these two glitches were the same - and sometimes musicians pretend they are. But they're not! So their ratio is a tiny meta-glitch. It's called the "schisma":

χ = p/σ = 32805/32768 ≈ 1.0011298906

and it was discovered by an advisor to the Gothic king Theodoric the Great.

In the most widely used tuning system today, a fifth is not 3/2 but slightly less: it's

2^(7/12) ≈ 1.4983070769

The ratio of 3/2 and this slightly smaller fifth is called the "grad":

γ = p^(1/12) ≈ 1.0011291504

Look! The grad is amazingly close to the schisma! They agree to 7 decimal places! Their ratio is a meta-meta-glitch called the "Kirnberger kernel":

χ/γ ≈ 1.0000007394

If you unravel the mathematical coincidence that makes this happens, you'll see it boils down to

2^(1/12) 5^(1/7) ≈ 1.333333192495

being very close to 4/3. And this coincidence let Bach's students Johann Kirnberger invent an amazing tuning system.

(1/2)

Much later the physicist Don Page, famous for discovering the "Page time" in black hole physics, became so obsessed with this coincidence that he wrote a paper trying to wrestle it down to something where he could do the computations in his head. For details and a link to that paper, read my blog post!

(2/2)

https://johncarlosbaez.wordpress.com/2024/01/25/well-temperaments-part-3/

Well Temperaments (Part 3)

Last time we saw the importance of some tiny musical intervals: irritating but inevitable glitches in our search for perfectly beautiful harmonies. Today I want to talk about a truly microscopic in…

Azimuth
@johncarlosbaez This got me wondering what else Page has on arxiv. Remarkable.
@johncarlosbaez When did you get into the maths and logic of music John? Your posts are really fascinating

@rmathematicus - thanks! It looks like I got into the math of tuning systems in October 2023. Before that I wrote a series of posts on modes starting in November 2022. The first of those posts starts with "I’ve been away from my piano since September. I really miss playing it. So, I’ve been sublimating my desire to improvise on this instrument by finally learning a bunch of basic harmony theory, which I practice just by singing or whistling." So, it's my two half-year visits to Edinburgh, and being away from my piano, that pushed me into music theory. Before then I'd always avoided mixing music and math, thinking that music was more fun if done intuitively!

https://johncarlosbaez.wordpress.com/2022/11/01/modes/

Modes (Part 1)

I’ve been away from my piano since September. I really miss playing it. So, I’ve been sublimating my desire to improvise on this instrument by finally learning a bunch of basic harmony …

Azimuth
@johncarlosbaez For various reasons I know, or better said once knew, most of this stuff, and its really nice to have it refreshed so beautifully
@johncarlosbaez
Have you ever taken a serious look at the theoretical disputes in the Early Modern Period over the lengths of the intervals on the scale, in particular the dispute between Gioseffo Zarlino (1517–1590) and his pupil Vincenzo Galilei (1520­–1591)? Then along comes Marin Mersenne ((1588–1648), he of the primes, and kaboom we have the modern scales and interval that are mainstream today

@rmathematicus - I haven't seen the dispute between Zarlino and Vincenzo Galilei. Where can I read about it? Do I have to read the original sources, or do you know some really good secondary literature.

I've been writing a long series of articles about the evolution of tuning systems from Pythagorean to just intonation (Ptolemy's intense diatonic scale) to quarter-comma meantone to various well-tempered systems to equal temperament, reading a lot about the work of old music theorists. "Kaboom we have the modern scales and intervals are mainstream today" leaves out a lot of steps. But you probably meant something specific by that!

@johncarlosbaez

The comment on Marin Mersenne was somewhat tongue in cheek but his "Harmonie Universelle" (Paris, 1636) is regarded as the foundation of modern scientific acoustics and music theory. A good place to start on the history of music theory of this era is H Floris Cohen, "Quantifying Music: The Science of Music at the First Stage of Scientific Revolution 1580–1650" (Springer, 1984) Out of print but should be in a university library near you.

@rmathematicus - thanks! I hadn't bumped into that book yet, and it sounds great for what I want!
@johncarlosbaez
Floris Cohen is an excellent historian of science and the book is regarded as a classic
@rmathematicus - I got ahold of a PDF. It's great so far.
@johncarlosbaez @johncarlosbaez thank you, I really enjoy your tuning system posts, and I would love to understand more about how Theodoric the Great achieved their discoveries

@Jermolene - I'm glad you're enjoying them! I didn't say Theodoric the Great discovered anything about music - he was probably way too busy with wars and political intrigues. It was his advisor, the famous philosopher Boethius, who did music theory. I wrote about his work here:

https://johncarlosbaez.wordpress.com/2023/11/08/boethius/

Boethius

There’s more to Boethius (480–524 AD) than I knew! Sure, he wrote On the Consolation of Philosophy while imprisoned, later to be executed. And sure, it contains worthy stoic chestnuts like No…

Azimuth