# luhmann (blogs) — RSS Amplifier Recent posts from the 2 feeds in the RSS Amplifier directory that cover luhmann. Page: Feed: --- ## [Sociología del envejecimiento 2: problemas sociales](https://sociologiadivertida.blogspot.com/2026/08/sociologia-del-envejecimiento-2.html) _2026-08-10 · Juan Carlos Barajas · Sociología Divertida_ Las edades y la muerte de Hans Baldung Grien (1544) que no se diga que no empezamos con alegría Resumen En el primer artículo de esta serie exploramos cómo el envejecimiento se ha convertido en un fenómeno social central y analizamos los procesos biológicos, psicológicos y sociales que lo acompañan. En este segundo texto abordamos los problemas concretos que afectan a las personas mayores: la… ## [Sociología del envejecimiento 1: la vejez en nuestra sociedad](https://sociologiadivertida.blogspot.com/2026/07/sociologia-del-envejecimiento-1-la.html) _2026-07-16 · Juan Carlos Barajas · Sociología Divertida_ El anciano con el nieto, de Domenico Ghirlandaio (1490) Resumen Este es el primero de una serie de cuatro artículos sobre sociología del envejecimiento. En este primer texto exploramos cómo el envejecimiento se ha convertido en un fenómeno social central y en cómo se envejece actualmente examinando la cuestión desde un punto de vista social. En los próximos artículos abordaremos los problemas… ## [Quince años tiene mi blog](https://sociologiadivertida.blogspot.com/2026/06/quince-anos-tiene-mi-blog.html) _2026-06-02 · Juan Carlos Barajas · Sociología Divertida_ Cuando yo era pequeño, yo diría que muy pequeño, el Dúo Dinámico —grupo musical que nos acompañó durante décadas— puso de moda una canción que se llamaba “Quince años tiene mi amor”. Así que, cuando empecé a pensar en qué escribir para el quince cumpleaños de Sociología Divertida, resonaba esa cancioncilla en mi cabeza, soniquete en el que cambiaba “amor” por “blog” y me dije: pues voy a ponerle… ## [(untitled)](https://chrisaldrich.wordpress.com/2026/02/20/55834689/) _2026-02-20 · Chris Aldrich · Chris Aldrich_ My website has been hobbling along for about two weeks now. Sadly I ve either been away or too under the weather to clean things up. Hopefully a bit of work this morning has improved things. We ll see how stable things are going forward. This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2026/02/03/cleaning-up-the-1936-royal-khm/) _2026-02-03 · Chris Aldrich · Chris Aldrich_ Wiped off the worst of dust and grime on the exterior of my 1936 Royal KHM standard typewriter. Cleaned up the carriage a bit and did a light oiling. Cleaned out the paper tray and platen area. Spooled up some new ribbon. After a few quick tweaks, this typewriter is now at least minimally usable. This post was originally published on Chris Aldrich ## [Un fallo en Matrix](https://sociologiadivertida.blogspot.com/2026/01/un-fallo-en-matrix.html) _2026-01-26 · Juan Carlos Barajas · Sociología Divertida_ Morfeo ofrece a Neo una pastilla roja y una verde Del guion de The Matrix (1999) (Neo observa el pasillo a su izquierda. Un gato negro camina con calma de fondo a primer plano y desaparece por la derecha. Neo lo sigue con la mirada, casi sin interés. Luego, en el MISMO lugar, un gato negro IDÉNTICO repite EXACTAMENTE el mismo recorrido, al mismo ritmo. Neo pestañea, confundido. Mira a Trinity, que… ## [(untitled)](https://chrisaldrich.wordpress.com/2026/01/23/on-which-typewriter-is-best/) _2026-01-23 · Chris Aldrich · Chris Aldrich_ This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2026/01/16/moon-reader-pro-rapid-serial-visual-presentation-rsvp/) _2026-01-16 · Chris Aldrich · Chris Aldrich_ TIL: Moon+ Reader Pro has RSVP technology hiding in it s settings! This is going to dramatically help my inspectional reading this year. This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2026/01/14/zotero-update-7-0-31/) _2026-01-15 · Chris Aldrich · Chris Aldrich_ I ve just noticed that Zotero update 7.0.31 added specific fields for Original Place, Original Publisher, and Original Date for books. Even better, the books for which I had defined an Original-date in the Extra section automatically sucked in that data and updated my database! Good work development team! This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2026/01/12/index-card-sale/) _2026-01-13 · Chris Aldrich · Chris Aldrich_ Because I often buy index cards in tranches of 5,000 to 10,000 at a time, I ve noticed that Oxford recently dropped their brick of 500 4 6 index cards to $6.47, a new low for the past year when they ve generally been hovering in the $8.50-9.50 range. As a competitive move, Amazon has dropped their competing brick This post was originally published on Chris Aldrich ## [Open directory of blogs (Sponsored)](https://crawlproof.com/a/qrZn4pTkCebP) _2026-01-13 · **Sponsored**_ Drop URLs or OPML — get per-blog pages plus machine-readable JSON, OPML, text ## [On Purchasing Typewriters: Condition is King; Context is Queen](https://chrisaldrich.wordpress.com/2026/01/08/on-purchasing-typewriters-condition-is-king-context-is-queen/) _2026-01-08 · Chris Aldrich · Chris Aldrich_ New typewriter enthusiasts will very often post to Reddit, one of the Facebook typewriter groups or other similar fora, something along the lines of: I spotted this typewriter at an antique store. Good condition to buy? and include a picture of some generic typewriter. It bears mentioning and thoroughly understanding that even an expert typewriter This post was originally published on Chris… ## [Niklas Luhmann’s Zettelkasten Method One Pager (1968)](https://chrisaldrich.wordpress.com/2026/01/02/niklas-luhmanns-zettelkasten-method-one-pager-1968/) _2026-01-03 · Chris Aldrich · Chris Aldrich_ The internet is now rife with what I call zettelkasten method one pagers that describe what many people rightly (or very often wrongly) think that Niklas Luhmann s zettelkasten method entails. While doing some research about Luhmann s numbering system s antecedents, I recently came across a one pager (typescript) written by Luhmann himself in the form of This post was originally published on Chris… ## [A comparison of A5 sized notebooks with 4 x 6 inch index cards on a cost per square foot basis](https://chrisaldrich.wordpress.com/2025/12/26/a-comparison-of-a5-sized-notebooks-with-4-x-6-inch-index-cards-on-a-cost-per-square-foot-basis/) _2025-12-26 · Chris Aldrich · Chris Aldrich_ Notebooks Product Sheet width (inches) Sheet height (inches) pages price Area sq. ft. $/sq. ft. Hobonichi A5 Graph 5.8 8.3 288 $23.00 96.3 $0.24 Leuchtturm 1917 A5 5.8 8.3 251 $25.95 83.9 $0.31 Moleskine Hard Cover 5 8.25 192 $20.00 55.0 $0.36 Travelers Notebook 4.3 8.3 128 $11.90 31.7 $0.38 4 x 6 inch This post was originally published on Chris Aldrich ## [La sociología de Sousa](https://sociologiadivertida.blogspot.com/2025/12/la-sociologia-de-sousa.html) _2025-12-26 · Juan Carlos Barajas · Sociología Divertida_ Resumen La sociología de Boaventura de Sousa Santos se define por su compromiso militante y su voluntad de ofrecer herramientas teóricas para enfrentar las injusticias de la globalización. Inspirándose en el concepto de cultura predominante en las ciencias sociales, la teoría del sistema-mundo de Wallerstein y el concepto de hegemonía cultural de Gramsci, junto con su propia experiencia en las… ## [(untitled)](https://chrisaldrich.wordpress.com/2025/12/22/55834056/) _2025-12-23 · Chris Aldrich · Chris Aldrich_ In part because of the Eaton Fire, I ve been way behind on filing my index cards. Today I blew through a massive stack of about 300 index cards! This post was originally published on Chris Aldrich ## [Breaking News: Brodart No Longer Manufactures or Sells Library Card Catalogs](https://chrisaldrich.wordpress.com/2025/12/12/breaking-news-brodart-no-longer-manufactures-or-sells-library-card-catalogs/) _2025-12-12 · Chris Aldrich · Chris Aldrich_ With no advance notice or apparent fanfare, Brodart, one of the major library supplies and furnishing companies in the United States, has quit manufacturing, distributing, and selling library card catalogs and library charging trays. This seems sad news for analog library enthusiasts coming just two days after Melvil Dewey s 174th birthday on December 10th. I ve This post was originally published… ## [(untitled)](https://chrisaldrich.wordpress.com/2025/12/11/brodart-index-cards/) _2025-12-11 · Chris Aldrich · Chris Aldrich_ Brodart has recently discontinued their salmon card index cards with pre-drilled holes #23-188-218. This has been a shift since the summer of 2025, though they re still carrying the standard salmon index cards (without predrilled holds for card catalog rods). A conversation with their customer service team seems to indicate there aren t plans for discontinuing their This post was originally… ## [Fundamentals Of Hypercomplex Numbers | UCLA Extension](https://chrisaldrich.wordpress.com/2025/12/03/fundamentals-of-hypercomplex-numbers-ucla-extension/) _2025-12-03 · Chris Aldrich · Chris Aldrich_ Dr. Michael Miller, a retired researcher at RAND, has been teaching upper level undergraduate/graduate level math courses for fun at UCLA Extension for over 50 years. This winter, he ll be introducing hypercomplex numbers to those interested in abstract math: Fundamentals Of Hypercomplex Numbers. His courses are thorough and rigorous, but geared toward lifelong learners and beginners This post was… ## [(untitled)](https://chrisaldrich.wordpress.com/2025/11/25/luhmann-didnt-even-invent-his-alpha-numeric-numbering-system/) _2025-11-26 · Chris Aldrich · Chris Aldrich_ I now have definitive written proof of a numeric indexing system (delineated in a popular textbook for secretaries, and published by a company which did significant business in Germany) from the mid-1920s with increasingly more detail into the 1940s and a fifth edition published in 1950. It s exactly like, but notably predates, Niklas Luhmann s alphanumeric This post was originally published on… ## [(untitled)](https://chrisaldrich.wordpress.com/2025/11/25/physical-characteristics-of-twenty-four-correspondence-filing-systems/) _2025-11-25 · Chris Aldrich · Chris Aldrich_ While digging about in indexing and filing systems, I ran across this chart created by the Oxford Filing Supply Company for a special Filing Supplies section of the May 1934 issue of Office Appliances magazine (Volume 59, Issue 5). It delineates the broad characteristics of most of the major commercially available filing systems of the This post was originally published on Chris Aldrich ## [Reach prospects with real signals (Sponsored)](https://crawlproof.com/a/Eh7Zai5Sl8pu) _2025-11-25 · **Sponsored**_ Find prospects talking about your problem and get context-backed moments to engage ## [Zettel of the Year Awards](https://chrisaldrich.wordpress.com/2025/11/21/zettel-of-the-year-awards/) _2025-11-22 · Chris Aldrich · Chris Aldrich_ In preparing for some of my end-of-the-year review from my card index, I thought it would be interesting to choose the Best Note of the Year . Then it thought it might be worth choosing a Best Insight , Most Surprising Note , and a Best Folgezettel as well. And if you re going to give out an award, This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2025/11/18/rsvp-to-indiewebcamp-san-diego-2025/) _2025-11-18 · Chris Aldrich · Chris Aldrich_ This has been one of my favorite events for the past two years, and after a rough 2025, this is a great way to cap off the year. Even better, Tantek has already suggested a session on card catalogs that s right up my alley: https://indieweb.org/2025/SD#Session\_ideas. This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2025/11/17/memindex-for-2026/) _2025-11-18 · Chris Aldrich · Chris Aldrich_ Watching people online chat, ask questions, and generally get excited about their planners for 2026, I thought I would spend a few minutes to set up my Memindex-inspired planner version using 4 x 6 index cards and tabbed dividers. It s amazing how useful a $2.50 block of 500 index cards can be for planning out This post was originally published on Chris Aldrich ## [You’re Invited to Another Southern California Type-In!](https://chrisaldrich.wordpress.com/2025/11/11/youre-invited-to-another-southern-california-type-in-november-29-2025/) _2025-11-11 · Chris Aldrich · Chris Aldrich_ “Like a jam session for people who like typewriters. You had unions do sit-ins and hippies do be-ins, so I thought, ‘We’ll do a type-in.’” —Michael McGettigan, 56, bike shop owner who coined the phrase With attendees from 8 months old to over 80, our Spring type-in was so successful, we re hosting another one before This post was originally published on Chris Aldrich ## [(untitled)](https://chrisaldrich.wordpress.com/2025/11/05/non-decorative-typewriters/) _2025-11-05 · Chris Aldrich · Chris Aldrich_ You know a typewriter is being used as flimsy filler decoration when it s sitting on a shelf and simultaneously serving as a book support. A real writer s typewriter is free and clear so that the carriage can move its full length. This post was originally published on Chris Aldrich ## [La tetera de Russell](https://sociologiadivertida.blogspot.com/2025/09/la-tetera-de-russell.html) _2025-09-25 · Juan Carlos Barajas · Sociología Divertida_ Resumen Este artículo analiza el estatuto lógico de la idea de Dios mediante un viaje intelectual que recorre la sociología de la religión de Durkheim, los rigores de la lógica formal, la metafísica de Russell y Epicuro, para finalmente regresar a la profunda visión sociológica de W.I. Thomas. Puede parecer un recorrido tedioso y exigente, pero a mi parece un viaje intelectual maravilloso. Por… ## [¿Qué es la lógica? ¿Hay una lógica sociológica?](https://sociologiadivertida.blogspot.com/2025/06/que-es-la-logica-hay-una-logica.html) _2025-06-10 · Juan Carlos Barajas · Sociología Divertida_ Arriba de derecha a izquierda: Aristóteles, Abelardo, Santo Tomás de Aquino, Guillermo de Ockham Abajo: Boole, Frege, Russell, Gödel, Turing Resumen Este artículo es una explicación de qué es la lógica formal, de su historia, de su influencia en la ciencia y, en particular, en la sociología. Se hace una revisión de cuatro teorías sociológicas, estudiando la lógica subyacente en sus planteamientos:… ## [Constructivismo social](https://sociologiadivertida.blogspot.com/2025/03/construccionismo-social.html) _2025-03-25 · Juan Carlos Barajas · Sociología Divertida_ Berger y Luckmann Resumen El constructivismo social ha emergido como una de las perspectivas más influyentes en las ciencias sociales contemporáneas, aunque su enseñanza y clasificación dentro de las corrientes sociológicas tradicionales han sido problemáticas. Su capacidad de infiltrarse en múltiples disciplinas, desde la sociología cultural hasta la economía, ha sido su mayor fortaleza y, al… ## [Un poco de luz acerca de MUFACE](https://sociologiadivertida.blogspot.com/2025/02/un-poco-de-luz-acerca-de-muface.html) _2025-02-18 · Juan Carlos Barajas · Sociología Divertida_ Resumen Los conflictos recurrentes entre el Gobierno y las aseguradoras privadas cada vez que expira un concierto ponen en el centro del debate público a la institución de MUFACE. Para que este debate sea serio y productivo, es indispensable un conocimiento mínimo del tema; sin embargo, en los medios se han difundido todo tipo de imprecisiones. Esta situación impide cualquier posibilidad de… ## [Realtime AI Arbitrage Terminal (Sponsored)](https://crawlproof.com/a/DyvQI4QwpFjg) _2025-02-18 · **Sponsored**_ Realtime auto-trading across exchanges with scored setups, backtesting, and risk controls. ## [La teoría del intercambio II: Blau](https://sociologiadivertida.blogspot.com/2024/12/la-teoria-del-intercambio-ii-blau.html) _2024-12-16 · Juan Carlos Barajas · Sociología Divertida_ Peter Blau Resumen George Homans sentó las bases de la teoría del intercambio, una perspectiva sociológica centrada en los intercambios de recompensas y costes en las interacciones sociales individuales. Este enfoque, inscrito en la microsociología, fue ampliado por Peter Blau, quien buscó explicar cómo los intercambios interpersonales influyen en la formación de estructuras sociales más…