I just couldn’t wait for a physical copy of The First Astronomers: How Indigenous Elders Read the Stars by Duane Hamacher, Ghillar Michael Anderson, Ron Day, Segar Passi, Alo Tapim, David Bosun and John Barsa (Allen & Unwin, 2022) to arrive in the US, so I immediately downloaded a copy of the e-book version.

@AllenAndUnwin @AboriginalAstro

Replied to a tweet by codexeditor (Twitter)
@brunowinck @codexeditor @alanlaidlaw When thinking about this, recall that in the second paragraph of The Mathematical Theory of Communication (University of Illinois Press, 1949), Claude Shannon explicitly separates the semantic meaning from the engineering problem of communication. 
Highlight from the book with the underlined sentence: "These semantic aspects of communication are irrelevant to the engineering problem.
@UCLAExtension I know a follow up course to the first half of Differential Topology is being offered for Winter 2022, but it doesn’t seem to be on the site yet to register. Can someone fix this?
Quoted Shape: The Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else by Jordan Ellenberg (Penguin Press)
You don’t make a bagel by first baking a bialy and then punching out the center. No—you roll out a snake of dough and join the ends together to form the bagel. If you denied that a bagel has a hole, you’d be laughed out of New York City, Montreal, and any self-respecting deli worldwide. I consider this final.
Not exactly a QED sort of proof, but I’ll take it as an axiom. 🙂

Differential Topology—Two quarter sequence at UCLA Extension for Fall/Winter 2021

It hasn’t been announced officially in the UCLA Extension catalog, but Dr. Mike Miller’s anticipated course topic for Fall 2021 is differential topology. The anticipated recommended text is Differential Topology: An Introduction by David B. Gauld (M. Dekker, 1982 or Dover, 1996 (reprint)).

The offering is naturally dependent on potential public health measures in September, which may also create a class limit on the number of attendees, so be sure to register as soon as it’s announced. For those who are interested in mathematics, but have never attended any of Dr. Miller’s lectures, I’ve previously written some details about his stye of presentation, prerequisites (usually very minimal despite the advanced level of the topics), and other details.

A few of us have already planned weekly Thursday night topology study sessions through the end of Spring and into Summer for those interested in attending. Just leave a comment with your contact information and I’ll be in touch with details.

I hope to see everyone in the fall.

An Euclidean Declaration

So far, my favorite part of Jordan Ellenberg‘s new book Shape: The Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else is this footnoted observation:

“we hold these truths to be self-evident” wasn’t Jefferson’s line; his first draft of the Declaration has “we hold these truths to be sacred & undeniable.” It was Ben Franklin who scratched out those words and wrote “self-evident” instead, making the document a little less biblical, a little more Euclidean.

Evie (taunting me to tuck her in before she gets to 15): …, 9-Mississippi, 10-Mississippi, 11-Mississippi, …

Me: We don’t Mississippi in this house! Maybe we should Tennessee since that’s where Grandma and Grandpa live?

Evie: I’ve Mississippi’ed since I was three.

Me: Maybe since we’re Welsh we should Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch? You know: 1-Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, 2-Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch, …

Together: 3-Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch…

Evie (interrupting): Wait, what number are we on now???

Bookmarked The Mountains of Pi by Richard Preston (The New Yorker)
The Chudnovsky brothers yearned to probe the mystery of pi, so they built their own supercomputer out of mail-order parts.
I know I’ve read this before. This is a good reminder to re-read it occasionally.

John Keilman on Twitter: “@rachsyme This one. It makes math make sense in a way nothing else has. https://t.co/VWST1TiQAZ”

Read Longtime philosophy Professor Stephen Barker dies at 92 (The Hub)
He was named professor emeritus after teaching in the Department of Philosophy for nearly four decades
I was thinking about logic a bit this evening and looked up an old professor. Saddened to hear he’s passed away.
Listened to The World, Remade from On the Media | WNYC Studios

How the pandemic has shaped our future: from the built environment, to the way we work, to the way we learn.

With vaccinations underway, we’re edging closer and closer to the end of the pandemic. This week, On The Media looks at how the pandemic has shaped what’s possible for the future — from the built environment to the way we work to the way we learn.

1. Sam Kling [@SamKling2], American Council of Learned Societies public fellow, on whether cities like New York were bound to become hubs for disease. Listen.

2. Vanessa Chang [@vxchang], lecturer at California College of the Arts, explains how pandemics of the past have been instrumental in shaping architecture; Mik Scarlet [@MikScarlet] delineates the social model of disability; and Sara Hendren [@ablerism], author of What Can A Body Do?: How We Meet the Built World, describes how the wisdom of people with disabilities can inform the redesign our post-pandemic world. Listen.

3. OTM reporter Micah Loewinger [@micahloewinger] tells the story of how distance learning saved his friend's life. Listen.

Read Postdoctoral position in HoTT at Johns Hopkins University by Emily RiehlEmily Riehl (Homotopy Type Theory)
The Department of Mathematics at Johns Hopkins University solicits applications for one two-year postdoctoral fellowship beginning Summer 2021 (with some flexibility in the start and end dates). Th…
Bookmarked The ergodicity problem in economics by Ole Peters (Nature Physics volume 15, pages1216–1221(2019))
The ergodic hypothesis is a key analytical device of equilibrium statistical mechanics. It underlies the assumption that the time average and the expectation value of an observable are the same. Where it is valid, dynamical descriptions can often be replaced with much simpler probabilistic ones — time is essentially eliminated from the models. The conditions for validity are restrictive, even more so for non-equilibrium systems. Economics typically deals with systems far from equilibrium — specifically with models of growth. It may therefore come as a surprise to learn that the prevailing formulations of economic theory — expected utility theory and its descendants — make an indiscriminate assumption of ergodicity. This is largely because foundational concepts to do with risk and randomness originated in seventeenth-century economics, predating by some 200 years the concept of ergodicity, which arose in nineteenth-century physics. In this Perspective, I argue that by carefully addressing the question of ergodicity, many puzzles besetting the current economic formalism are resolved in a natural and empirically testable way.
Kevin Marks retweet () of 
Simon Wardley @swardley in Simon Wardley on Twitter: “Anyway, this is a fabulous paper – The ergodicity problem in economics – https://t.co/fzS3toWvT5 … well worth the read.” / Twitter ()
Annotated The ergodicity problem in economics by Ole Peters (Nature Physics volume 15, pages1216–1221(2019))
Ergodic theory is a forbiddingly technical branch of mathematics. 
It’s supremely sad that a paper in Nature should “math shame” ergodic theory this way. What the hell is going on?