chestertn

Lucky

Tech senior

Could it be muscle loss?

I really disliked the book. Probably one of the worst books I’ve ever read.

Some times HN shows well-written and researched blog pieces about events or characters in scientific history. This book felt like the author read a bunch of these and put them together in a book. Then the reality-fantasy aspect of it makes no sense to me.

Why did you like it?

I think it’s also the design philosophy. JuMP and ForwardDiff are great success stories and are packages very light on dependencies. I like those.

The DiffEq library seems to pull you towards the SciML ecosystem and that might not be agreeable to everyone.

For instance a known Julia project that simulates diff equations seems to have implemented their own solver

https://github.com/CliMA/Oceananigans.jl

That page is a bit marketing

One of the things I don't like about the Julia ecosystem is the monolithic libraries that have tons of dependencies. DiffEq is one of those. I think its fine to write a script but if you want to develop something more sophisticated, you want to keep your dependencies lean.

Im not sure if Julia will ever take off. Right now there are huge investments in the AI space and Julia has no presence in those.

Is it? Chatgpt and variants are a great product at least. I use it every day. My wife (nontech) also does it.

I’m sure this question has been asked plenty of times but what is the best place to start with LLMs (no theory, just installing them locally, fine tuning them, etc)

Is this bad for research?

I pasted paragraphs from old academic papers (90s) and gave me 97-100% AI generated. Have you even tested this?

That part about Gibson doing a documentary is not true. Just Google it.

Publishing is a social activity. And, today, a bad metric to measure research success. It has been hijacked by careerists and mafiosi.

Pretty good!

Great!

Any paid course that you recommend?

Stephen Boyd’s course on Convex Optimization https://see.stanford.edu/Course/EE364A

Have you tried Julia?

I will save you the pain: switch to Julia.

Hi again :). We both have an axe to grind.

I was just giving some support to the parent comment about the scale of sacrifices compared with the Spanish inquisition.

Even if the number is 4000, its still quite comparable with the number of executions of the Spanish inquisition over 3 centuries.

About [1], yes, I do not dispute that. But we were comparing different systems and that the Aztec system was much more cruel from a modern standard.

According to Wikipedia. Spanish Inquisition executed between 3000 and 5000 people over 3 centuries: https://en.m.wikipedia.org/wiki/Spanish_Inquisition

According to this article. “When the Great Pyramid of Tenochtitlan was consecrated in 1487 the Aztecs recorded that 84,000 people were slaughtered in four days”

https://qz.com/374994/aztec-sacrifice-was-real-and-its-not-f...

So, the math checks out.

Related: https://guerrillafoundation.org/wp-content/uploads/2018/03/n...

I do not have nice food at home.

The "water" moves near light speed effectively

This is not how the hydraulic analogy works. The "speed" of the water is irrelevant. The analogy is used to understand losses, energy balance, energy conservation, reactive power, etc.

The hydraulic analogy is very sound.

The water analogy is perfectly fine to use to talk about the bulk AC transmission grid (which is low-frequency alternating current).

photochemsyn speaks about how the hydraulic phenomena is not adequate to describe some electronic aspects (e.g., modeling p-n silicon junctions). These issues are irrelevant to how well the hydraulic analogy works to describe the workings of the AC transmission grid.

A load being inductive, capacitive, or reactive has to do with its impedance, which is a concept related to the steady-state analysis of AC networks.

The hydraulic analogy easily extends here - just imagine water flowing back and forth.

This is well studied [1] and power engineering books make use of this analogy.

[1] https://en.wikipedia.org/wiki/Hydraulic_analogy.

We are talking about electrical water analogies.

Stability issues are beyond the network being electrical and correspond to the electromechanical dynamics of the grid.

These types of analogies are very sound and well studied [1].

Great power engineering books, such as Olle Elgerd's Electric Energy System Theory, make extensive use of these.

https://en.wikipedia.org/wiki/Mechanical–electrical_analogie...

In the pipes analogy, pressure corresponds to potential energy (voltage). Low voltage conditions does not necessarily trigger frequency stability issues.

Grid synchronization is a different issue to the electrical-hydraulic analogy (which, by the way, was the one that Maxwell used and its pretty useful). Grid synchronization comes from the fact that electrical quantities in the network (current, voltage) are alternating periodic. Generators, which are usually mechanical, oscillate and induce such periodic signals. The system must remain synchronized. But this has nothing to do with the network being electrical.

[1] https://en.wikipedia.org/wiki/Hydraulic_analogy

Water tank and water pipe analogies fail pretty fast when it comes to thinking about electricity.

In what ways does this analogy fail, for the purposes of understanding power grids?