This is where "fun" stuff is likely to be.
These people are cool.
They use optical tweezers to place individual atoms floating in midair, and then do stuff to entangle their nuclear spins.
All the financial advice you’ll ever need fits on a single index card Updated 2025-01-06 +Created 1970-01-01
This is a good concept. For the ammount most people save, having a simple and easy to apply investment thesis is the best way to go.
Fixed total angular momentum.
The direction however is not specified by this number.
To determine the quantum angular momentum, we need the magnetic quantum number, which then selects which orbital exactly we are talking about.
Framework built on top of React.
Officially recommended by React[ref]:
Recommended ToolchainsIf you’re building a server-rendered website with Node.js, try Next.js.
gothinkster/realworld blog example by Ciro Santilli: node Express Sequelize Next.js realworld example app.
Basically what this does is to get server-side rendering just working by React, including hydration, which is a good thing.
Next.js sends the first pre-rendered HTML page along with the JavaScript code. Then, JavaScript page switches just load the API data.
Next.js does this nicely by forcing you to provide page data in a serialized JSON format, even when rendering server-side (e.g. the return value of
getServerSideProps). This way, it is also able to provide either the full HTML, or just the JSON.Some general downsides:
- it does feel like they don't document deployment very well however, especially non-Vercel options, which is the company behind Next.js. I'm unable to find how to use a non Vercel CDN with ISR supposing that is possible.
- Next.js is very opinionated, and like any opinionated library it is sometimes hard to know why something is/isn't happening, and sometimes it is hard/impossible to do what you want with it unless they add support. They have done good progress, but even as of 2022, some aspects just feel so immature, some major-looking use cases are not very well done.
In theory, Next.js could be the "ultimate frontend framework". It does have a lot of development difficulties that need to be ironed out, but the general concepts, and things it tries to integrate, including e.g. webpack, TypeScript, etc. are good. Maybe the question is when will someone put it together with an amazing backend library and dominate and finally put an end to the infinite number of Js Frameworks!
In-tree examples at: github.com/vercel/next.js/tree/canary/examples
In order to offer its amazing features, Next.js is also extremely opinionated, which means that if something wasn't designed to be possible, it basically isn't.
No prerender with custom server? It forces you to write your API with next as well? Or does it mean something else?
TODO can it statically generate pages that are created at runtime? E.g. if I create a new blog post, will it automatically upload a static page? It seems that yes, and that this is exactly what Incremental Static Regeneration means:However, Ciro can't find any mention of how to specify where the pages are uploaded to... this is pat of the non-Vercel deployment problem.
- github.com/vercel/next.js/discussions/25410
- vercel.com/docs/next.js/incremental-static-regeneration
- github.com/vercel/next.js/discussions/17711
- www.reddit.com/r/nextjs/comments/mvvhym/a_complete_guide_to_incremental_static/
- github.com/vercel/next.js/discussions/11552#discussioncomment-115595
- stackoverflow.com/questions/62105756/how-to-use-aws-with-next-js
- github.com/vercel/next.js/discussions/17080
- github.com/vercel/next.js/discussions/16852
Can't ISR prerenter by URL query parameters:
That plus the requirement to have one page per file under
pages/ leads to a lot of useless duplication, because then you are forced to place the URL parameters on the pathnames."Module not found: Can't resolve 'fs'" Hell. The main reason this happens seems to be the that in a higher order component, webpack can't determine if callbacks use the require or not to remove it from frontend code. Fully investigated and solved at:
Overviews:
- www.reddit.com/r/reactjs/comments/8evy5d/what_are_the_downsides_to_nextjs/ 2017 What are the downsides to Next.js?
TODO understand a bit more intuitively.
- Physics from Symmetry by Jakob Schwichtenberg (2015) page 72
- physics.stackexchange.com/questions/172385/what-is-a-spinor
- physics.stackexchange.com/questions/41211/what-is-the-difference-between-a-spinor-and-a-vector-or-a-tensor
- physics.stackexchange.com/questions/74682/introduction-to-spinors-in-physics-and-their-relation-to-representations
- www.weylmann.com/spinor.pdf
DNA stuff at: human mtDNA.
The type of feeling of confusion and distrut for your sense that some Koans attempt to instill.
Ciro Santilli's preferred version of it is physics and the illusion of life.
Some notable references:
- kotobank.jp/word/大疑-556655 quotes passing referenes by
- Nichiren (1272)
What should I do?
- Sasamegoto (1463-64)
The square is without Daigo because there is no doubt
- Nichiren (1272)
- en.wikipedia.org/wiki/Hakuin_Ekaku#Taigi_%E2%80%93_great_doubt mentions Hakuin Ekaku's take
en.wikipedia.org/wiki/Logarithm_of_a_matrix#Existence mentions it always exists for all invertible complex matrices. But the real condition is more complicated. Notable counter example: -1 cannot be reached by any real .
The Lie algebra exponential covering problem can be seen as a generalized version of this problem, because
- Lie algebra of is just the entire
- we can immediately exclude non-invertible matrices from being the result of the exponential, because has inverse , so we already know that non-invertible matrices are not reachable
- www.linkedin.com/in/howelzy/Epic.
Might know a thing or two about landfills.
- www.independent.co.uk/news/uk/home-news/lost-bitcoin-crypto-james-howells-b2406517.htmlThe bizarre saga started in 2013 when Mr Howells, put the hardware from an old laptop that contained 8,000 bitcoins, the world’s leading cryptocurrency, in a black bag in his hallway."I was doing a clear-out in my office and put a lot of items into a bag which I then placed at the front door of my house," he said. "I woke up the next morning and my ex-partner had already taken the bags to the landfill site; she thought she was doing me a favour, it wasn’t her fault."
- www.bbc.co.uk/news/uk-wales-67297013
Timeline:
- 2021-08-02 arrested in the USA for extradiction
- 2023-11-06 Stepped down from monero Core Team
In this section we will use the file nodejs/bench_mem.js, tests are run on Node.js v16.14.2 from NVM, Ubuntu 21.10, on Lenovo ThinkPad P51 (2017) which has 32 GB RAM.
Related answer: stackoverflow.com/questions/12023359/what-do-the-return-values-of-node-js-process-memoryusage-stand-for/72043884#72043884
First using
topp from stackoverflow.com/questions/1221555/retrieve-cpu-usage-and-memory-usage-of-a-single-process-on-linux/40576129#40576129 let's observe the memory usage of some baseline cases.A C hello world with an infinite loop at the end has:
- 2.7 MB
- 770 KB
For a Node.js infinite loop nodejs/infinite_loop.jsThis gives approximately:
topp infinite_loop.js- RSS: 20 MB
- VSZ: 230 MB
Adding a single hello world to it as in nodejs/infinite_hello.js and running:leads to:We understand that Node.js preallocates VSZ wildly. No big deal, but it does mean that VSZ is a useless measure for Node.js.
topp infinite_hello.js- RSS: 26 MB
- VSZ: 580 MB
Forcing garbage collection as in nodejs/infinite_hello.js brings it down to 20 MB however:
topp node --expose-gc infinite_hello_gc.jsFinally let's see a baseline for which gives initially:but after a few seconds randomly jumps to:so we understand that
process.memoryUsage nodejs/infinite_memoryusage.js:node --expose-gc infinite_memoryusage.js{
rss: 23851008,
heapTotal: 6987776,
heapUsed: 3674696,
external: 285296,
arrayBuffers: 10422
}{
rss: 26005504,
heapTotal: 9084928,
heapUsed: 3761240,
external: 285296,
arrayBuffers: 10422
}heapUsedseems constant at 3.7 MBheapTotalis a very noisy, as it starts at 7 MB, but randomly jumps to 9 MB at one point without apparent reason
Now let's run our main test program.
First a baseline case with an array of length 1:This gives the same results as with:
node --expose-gc bench_mem.js n 1node --expose-gc infinite_memoryusage.js. The same result is obtained by doing:a = undefinednode --expose-gc bench_mem.js deallocNot let's vary the size of which gives:
n a bit with:node --expose-gc bench_mem.js n N| N | heapUsed | heapTotal | rss | heapUsed per elem | rss per elem |
|---|---|---|---|---|---|
| 1 M | 14 MB | 48 MB | 56 MB | 10 | 30 |
| 10 M | 122 MB | 157 MB | 176 MB | 18 | 15 |
| 100 M | 906 MB | 940 MB | 960 MB | 9 | 9.3 |
"
rss per elem" is calculated as: rss - 26 MB, where 26 MB is the baseline RSS seen on n 1.Similarly "
heapUsed per elem" deduces the 4 MB (approximation of the above 3.7 MB) seen on n 1.Note that to reach MAX_SAFE_INTEGER we would need 8 bytes per elem worst case.
Everything below 100 million (8) is therefore very memory wasteful in terms of RSS.
If we use we see that the memory is now, unsurprisingly, accounted for under Results for different N:We see therefore that typed arrays are much closer to what they advertise (4 bytes per element), even for smaller element counts, as expected.
Int32Array typed array buffers instead of a simple Array:node --expose-gc bench_mem.js array-buffer n NarrayBuffers, e.g. for N 1 million:{
rss: 31776768,
heapTotal: 6463488,
heapUsed: 3674520,
external: 4285296,
arrayBuffers: 4010422
}|| N
|| `arrayBuffers`
|| `rss`
|| `rss` per elem
| 1 M
| 4 MB
| 31 MB
| 5
| 10 M
| 40 MB
| 67 MB
| 4.6
| 100 M
| 40 MB
| 427 MB
| 4Now let's try one million objects of type gives:Disaster! Memory usage is up to 70 MB! Why?? We were expecting only about 24, 4 baseline + 2 * 10 for each million int?!
{ a: 1, b: -1 }:node --expose-gc bench_mem.js obj{
rss: 138969088,
heapTotal: 105246720,
heapUsed: 70103896,
external: 285296,
arrayBuffers: 10422
}And now an equivalent version using gives the same result.
class:node --expose-gc bench_mem.js classLet's try Array:is even worse at 78 MB!! OMG why.
node --expose-gc bench_mem.js arr{
rss: 164597760,
heapTotal: 129363968,
heapUsed: 78117008,
external: 285296,
arrayBuffers: 10422
}Let's change the number of fields on the object? First as a sanity check:produces as expected the smae result as:so adding properties one by one doesn't change anything from creating the literal all at once. Good.
node --expose-gc bench_mem.js obj 2node --expose-gc bench_mem.js objNow:gives
node --expose-gc bench_mem.js obj NheapUsed:- 1: 70M
- 2: 70M
- 3: 70M
- 4: 70M
- 5: 110M
- 6: 110M
- 7: 110M
- 8: 134M
- 9: 134M
- 10: 134M
- 11: 158M
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