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mbustamanteron Loss of cell identity drives human aging: Two new papers

I suppose the stress was running away from a lion, not having the all-eating thought of meeting deadlines, a bad boss, backstabbing coworkers and so on, i.e. intense, but short, not persistent and chronic.

mbustamanteron Wacky Fun Physics Ideas

One of the most fascinating characters out there for sure, without fail his posts make me consider a new perspective.

He left HN unfortunately, he might be too brash for this site (or this place is too wimpy for him).

mbustamanteron 150 years of Hans Christian Andersen

I read The Steadfast Tin Soldier for the first time when I was a kid but it didn't have a special meaning for me until my late teens, when I first fell in love.

mbustamanteron PlasticList – Plastic Levels in Foods

It's easier to walk up to the woman that's been eyeing you at the party, speaking from experience.

mbustamanteron Interview with gwern

There is a comment on the r/slatestarcodex subreddit with supposedly true information about him (which I found googling 'who is gwern'), but it left me with even more questions.

EDIT: grammar

mbustamanteron A simple proof that pi is irrational [pdf] (1946)

For anyone interested who could not follow the reasoning in the paper, it is explained extensively in this video [0] by Michael Penn.

[0] https://www.youtube.com/watch?v=dFKbVTHK4tU

mbustamanteron SymPy: Symbolic Mathematics in Python

Symbolic mathematics is severely underexplored in undergraduate studies, and the little exposure I had was generally tied to proprietary software such as Mathematica and MATLAB. I learned to use it as an imperfect extension of pen-and-paper thinking, and source code for more advanced stuff gets shaky the deeper into abstraction one goes. For example, I work in a field of mathematics/engineering that requires heavy use of tensor calculations. My go-to tool for that is Maxima, however, it has limited and cumbersome packages for it (see [0]). Now for more sophisticated calculations I resort to SymPy, not necessarily because of better handling of symbolics but because of the abstractions that Python already has. Maybe someday I'll get to read the Principles by Norvig and fix Maxima to suit my needs (if anyone has better references to read Maxima's source code/implementation of tensor computations/symbolic (tensor, geometric) algebra I would be grateful to know).

[0] https://arxiv.org/pdf/cs/0503073.pdf

mbustamanteron Ten years of remembering every day that passes (2022)

The moments captured in my images are fresh, but my perspective on them changes.

I am doing an experiment in memory and trying to memorize the name of every U.S. county, with the aid of a map. Several months in I can say that the brain inexorably will tie names together (wether by geographical proximity or etymology, e.g. Imperial-Riverside-San Diego or Redwood-Greenwood), and the addition of new names affects the perception of the ones before, or the perception of words which happen to be county names. I could write an entire essay on the limits of memory, but it would hardly be better than Jorge Luis Borges's story Funes, the memorius.

For anyone curious I can name 80% of U.S. counties with the aid of a blank map, and my geographic intuition has improved greatly. Every county (and county name) has a history attached to it, and sometimes when someone tells me where they grew up, I can guess their ancestry more or less, especially if they come from rural areas. It surprises them, sometimes even more when they know I'm not american.

mbustamanteron What is going on in Argentina?

In order to have a mature discussion about this topic, it's necessary for people to know about the economic and political history of Argentina. It's impossible to understand their current situation without going back to the 1940s. Bad faith arguments look over the fact that Argentina has had decades of incredible economic distortions as a consequence of political rot, and that undoing those distortions is not achieved in the time Milei has been president (I personally don't believe they could be undone in less than a presidential term).

mbustamanteron Thomas Cochrane

He is known by all members of the Chilean Navy [1], he is not obscure in this part of the world. By the way, I am chilean and lived most of my childhood just a block away from Lord Cochrane street [0], in downtown Santiago, which is one the busiest places in the whole country (and those adjacent blocks have seen some history).

[0] https://www.google.com/maps/place/Lord+Cochrane+1-99,+Santia...

[1] https://www.memoriachilena.gob.cl/602/w3-article-726.html (documents, images and more)

mbustamanteron GNU/Linux Aviation HOWTO (2006)

As an occasional general aviation pilot (I found this HOWTO after trying to find tools to aid in flight plan calculations), I think it would be great if we took it a step further and make a full-fledged Linux avionics system, but it seems unlikely [0]. And Garmin will likely not be replaced in a dozen years.

[0] https://aviation.stackexchange.com/questions/36853/do-safety...

mbustamanteron Exposition of a New Theory on the Measurement of Risk (1738) [pdf]

I read the two first or so papers of the book and understood them, but I coulnd't get past because I lack the sufficient probability theory (I'm a functional analyst). Now it's been in my queue for some time but I hope to get to it after finishing the references I'm reading now.

mbustamanteron How Japan is tackling a syndrome that creates recluses

Didn't the german chancellor say recently that Germany would have to take in 1.5 million immigrants a year so that its pension system wouln't collapse? I personally don't think that is the solution but Spain is going through a similar phenomenon (pensions-low TFR).

mbustamanteron Stem Formulas

Cool! I've just contributed several examples. If anyone is interested in the sheer amount of identities that have been discovered, good books are (many of them gigantic references spanning thousands of pages). When bored, try proving some of those facts, examples build on top of each other. These are not the only examples, as there are many texts like these in other areas of mathematics and engineering, be it numerical analysis, optimization and variational analysis, statistics, abstract algebra, control theory, geometry and so on.

Table of Integrals, Series, and Products, Gradshteyn & Ryzhik.

Special Integrals of Gradshteyn and Ryzhik, Vols. I and II, Moll for some proofs of the above.

Handbook of Integral Equations, Polyanin & Manzhirov.

Scalar, Vector, and Matrix Mathematics, Bernstein.

Handbook of Number Theory I and II, Sandor, Crstici & Mitrinovic.

Wikipedia also has a plethora of pages with mathematical identities. Some of them:

https://en.wikipedia.org/wiki/Vector_calculus_identities

https://en.wikipedia.org/wiki/Vector_algebra_relations

https://en.wikipedia.org/wiki/Exterior_calculus_identities

https://en.wikipedia.org/wiki/Del_in_cylindrical_and_spheric...

https://en.wikipedia.org/wiki/List_of_formulas_in_Riemannian...

https://en.wikipedia.org/wiki/List_of_set_identities_and_rel...

https://en.wikipedia.org/wiki/List_of_triangle_inequalities

https://en.wikipedia.org/wiki/List_of_trigonometric_identiti...

... and its several lists of integrals (including trigonometric, exponential, rational).

https://en.wikipedia.org/wiki/Lists_of_integrals#Lists_of_in...

More advanced topics:

http://proximity-operator.net/

mbustamanteron PhD Simulator

I'm a chilean maths grad student and save for the qualifying exam, it's quite accurate. So much so that I think I made a mistake clicking on this because as it progressed I started feeling dizzy. Other commenters here also have their relatable experiences, which doesn't make me feel so bad.

mbustamanteron Ernst Jünger’s narratives of complicity

He was born in the German Empire, fought in both world wars, lived through Weimar, rise of the Soviet Union, rise of the Third Reich, saw his country split in two, saw the Berlin wall fall and the collapse of the USSR. That's a very high bar for me to reach, and I don't know what the modern equivalent would be.

mbustamanteron The Matrix Cookbook (2012) [pdf]

This cookbook was insightful in the sense that I once tried proving several of its identities via Kronecker products but then found that it was much easier using tensor notation, so easy that I almost forgot Kronecker products altogether. I put together some proofs in my blog [0] (note: it's incomplete and the URL might change!).

[0] https://mbustamanter.github.io/ssg-blog/2022/matder1/

mbustamanteron Ask HN: What are your favorite sci-fi books?

Two favorite books of mine I've seldom seen mentioned but I think are gems: The three stigmata of Palmer Eldritch and Time out of joint, both by Philip K. Dick. The first plays with several layers of reality along the book. One time I found myself re-reading some passages because there were so many layers it was hard to follow, but it's worth it. The second is (if I recall correctly) the inspiration for a 90s pop movie starring Jim Carrey. I won't mention the name because it might give away some plot points.

mbustamanteron FreeBSD spends 7% of its boot time running a bubblesort on its SYSINITs

Not even noon and Colin is already roasting. Reminds me of [0], also by him.

[0] https://news.ycombinator.com/item?id=35079

mbustamanteron Tell HN: Putting mirrors around my desk improved my posture

Slightly related: Does anyone else can't concentrate for long periods of time while sitting in front of a computer? I have mild scoliosis and a fear of varicocele (if that's relevant), and fortunately my work involves implementation of numerical algorithms/problem solving that I can first sketch on a notebook while laying on my bed and finally be coded sitting -on a rush-. Same with reading books. I'm thinking of purchasing a one-sided divan sofa and put it next to my desktop.

mbustamanteron Argentina Is Going Broke to Stall a Full-On Currency Collapse

https://archive.is/mcoKm

mbustamanteron Large Photonic Processor Solves Graph Problems

That happens when the post has been queued to the second-chance pool: https://news.ycombinator.com/pool

mbustamanteron Ask HN: Is being remote affecting your job search?

I prefer using FOSS apps. See https://news.ycombinator.com/item?id=34343297

mbustamanteron Ask HN: Is being remote affecting your job search?

Yes, 45k USD remote for US companies, as opposed to entry level salary for MSc grads of 18k for the field I'm working in, in Chile. As I said, that's the lowest salary offer of remote jobs. The theory is numerical analysis of partial differential equations, specifically, the finite element method (for CFD, fluid-structure interaction, thin shell mechanics, buckling, and so on). To have a basic understanding of how to code custom FEM programs one needs at least an understanding of the fundamentals of functional analysis + analysis of PDEs + tensor calculus + the specific theory of physical application involved. These are non-trivial skills that take years and years to develop, so I would advise to anyone interested that it's best to get a job as a dev instead. I do it out of passion and because my family has a history of civil/mech eng.

The reason for such spread, I suspect, is that there is not much market for FEM professionals outside of the US and Europe, and if it exists, it's very small and unsophisticated.

mbustamanteron Ask HN: Is being remote affecting your job search?

I want to start off by saying that I am not a dev, my job is engineering that uses advanced mathematical theory to solve physical problems.

I have only set up a LinkedIn profile. Recruiters have my email from there, the conferences I've attended and contact information I've passed to my friends (being an engineering grad student helps). It varies, but the lowest is 45k/year, which living in the capital (even more if I lived in a village) of Chile means that as a single male I would live comfortably and without worries.

mbustamanteron Ask HN: Is being remote affecting your job search?

Precisely, it baffled me how people here went on with it seeing only the first order consequences. I'm a grad student in Chile and I get emails from recruiters in the US three or four times a week. I haven't picked up a job and don't plan to until I finish my degree (soon), and I haven't thoroughly evaluated the quality of each offer. Meanwhile recruiters in my country don't look as much, might as well be because American employers have much to gain from a remote worker compared to local employers. Several of my friends are from Argentina, and they all work for US companies either remotely or on-site, something I would have had a hard time believing just five years ago. This decade will be interesting.

mbustamanteron Governments should compete for residents, not businesses

Middle income countries are also facing demographic busts (although years later compared to rich countries). Competing for highly-skilled human capital, not massive third world immigration is essential, the main reason beaing that advanced economies with generous welfare are most affected by falling birth rates, and migrants to rich countries take as little as a single generation to adopt similar reproductive patterns relative to native populations (i.e. sub-replacement TFR: asian and east-asian to north america are the greatest example of this, but also hispanics and muslims to a lesser extent have collapsing birth rates). Even more dangerous to a stable economy is, that with a generous welfare system an invereted population pyramid will not be enough to sustain it, aging immigrant populations will exacerbate the problem: again, sub-replacement TFR in at most 2 gens. At most it will delay the demographic problem, however I personally think that focus on industrial automation will be more important.

See also my comment from a previous thread: https://news.ycombinator.com/item?id=34909400

mbustamanteron Ask HN: Has anyone started over outside of tech?

Thank you for sharing your experience, I'm really interested in this! I daydream daily of going rural while still building technology, also I agree with you that real wealth like land is essential for the future given current trends for jobs (Adam Smith spoke in his time about the real wealth of owning land), I suspect but not sure completely that starting a family in a farm will be advantageous since most education could potentially be descentralized. Also interested in different economic communities for different scales (co-ops and such), I happen to have read several localist advocates.

That being said, do you have any resource material or references on this? I'm on the verge on making the move and I will be starting soon.

mbustamanteron South Korea Again Smashes Own Record for World’s Lowest Fertility Rate in 2022

I wonder how different countries will react to this exceptional context in the next two decades. To give an idea of the novel nature of this demographic crisis:

1. Some demographers say that for the first time in recorded history the total fertility rate of the world will be just under replacement this year (2022 TFR=2.24, world replacement level being 2.23, as opposed to ~2.1 for first world countries).

2. Middle income countries are en-masse entering a stage of low fertility, a phenomenon that 50 years ago was only observed in few high-income countries. Even some poor countries have a rapidly declining fertility with few of them under replacement, and a bit more poor countries are expected to join this under-replacement stage. This means that immigration as we know it will change in demographics and magnitude, since the source countries will have their own problems as well.

3. Aging developed countries will perhaps have to change their approach to immigration: Canada is the poster child on what not to do and is being observed by several researchers around the world to have a glimpse of what's to come. A vicious cycle is born: Their native youth has not a broad margin by which to start families, so to compensate they take in high levels of immigrants relative to their population (Century initiative, as called by their government), little jobs or housing is added (for a variety of reasons, not all of them political) and home prices go up while wages in several professions are depressed, back to square one. This is particularly pernicious in Canada given their welfare system for elderly citizens, their immigrants aren't having enough children to compensate and in some regions their TFR is actually lower than that of the native population. The bane of a generous pension system is an inverted population pyramid, this is only exacerbating the problem. To ensure non-collapse either migrants have to put a lot more than they give or they take increasingly more immigration. It seems Canada already choose, and has a window of a couple decades given what I just said in point 2.

4. How will other developed countries react? Will they become high-tax gerontocracies like future Italy where the youth has to escape from for professional and entreprenurial aspirations? Or will they battle for high-quality immigration instead and make their economies more competitive and dynamic? Will they rely on their diaspora in Latin-America to compensate (such as german, spanish, japanese, croatian, italian, portuguese) like Spain and Italy are already doing, in the style of a great recalling? Will they, like Canada, start recalling mennonite communities from Mexico? In the US, will the amish carry the bulk of births in rural counties and Hasidic jews offset the birth crisis in urban areas (they both have a falling TFR, but still greatly above replacement)? Israel's TFR is solid and their population pyramid is actually a pyramid, do we look at them on what to do? Many african cities are on the brink of having sub-replacement TFR, will they have internal migration within the same continent instead of external movements?

mbustamanteron 3D Model of New York Available for Free (and Commercial Use)

Do you have a model of the twin towers within it?