I had no idea, but this "wiggle" is required for an optimal approximation, it's called the "equioscillation property" [https://en.wikipedia.org/wiki/Equioscillation_theorem].

For a polynomial P (of degree n) to approximate a function F on the real numbers with minimal absolute error, the max error value of |P - F| needs to be hit multiple times, (n+2 times to be precise). You need to have the polynomial "wiggle" back and forth between the top of the error bound and the bottom.

And even more surprisingly, this is a necessary _and sufficient_! condition for optimality. If you find a polynomial whose error alternates and it hits its max error bound n+2 times, you know that no other polynomial of degree n can do better, that is the best error bound you can get for degree n.

Very cool!

I'm interested in the topic, and the book cover looks great, so I'll probably read it.

But it seems a bit "Maintenance: For Boys". The items mentioned on this page are "the maintenance of sailboats, vehicles, and weapons", and "Soviet tanks, or tricked-out Model Ts".

No mention that for millenia we were mending our clothes, cleaning our houses, maintaining our food systems.

The reason this book sounds interesting is that maintenance is systematically undervalued, and basically in our human history pushed onto women and the lowest social classes. But the marketing material seems to highlight only the "sexy" stuff like weapons and vehicles. Where's the maintenance of washing our hands, washing our clothes, cleaning our streets?

There's this artist, Mierle Laderman Ukeles, who was the "Artist in Residence" at NYC's department of sanitation in the 70s, and tried to use conceptual art as a way to highlight the work of the department and make "maintenance art" a thing. I'm interested in that kind of re-valuing of maintenance.

I bet this book will be interesting, I just don't like the framing as "Maintenance: Of Everything" since it's clearly not the whole story. Hopefully part 2 has a broader scope and mindset.

Yeah, uv is cool and a step above conda, but that business model doesn’t look very profitable…

They did say they want their thing to have understanding of the code, so maybe they’ll sell semgrep-like features and SBOM/compliance on top. Semgrep is ok popular, but if it maybe bundled into something else (like the package registry itself) that might get enough people over the line to buy it.

Private registries and “supply chain security” tools individually aren’t the hottest market, but maybe together the bundle could provide enough value. Let’s see how it goes.

yeah but they're still >50% off SFBA salaries. SFBA comp for a sr dev can easily be $200k+ (and can go higher, lots of anecdotes on here about $350k+ salaries at BigtechCos), for an EU dev scratching 90k euro is considered "good". Devaluing the dollar by 10% and increasing the price of EU salaries by 10% doesn't really change the picture.

Oh this is great! I always have this problem. I find that's one of my biggest barriers when reading queueing theory content. I'm only doing it intermittently so I don't have memorized the meanings of ρ,σ,μ,λ...

Visually I also often confuse rho and sigma, and math texts will use psi ψ and phi φ in weird fonts and I can never tell them apart.