We appear to be edging ever closer to a solid statement of “We are not alone” in the universe with this week’s announcement of the detection of biosignatures in the atmosphere of exoplanet K2-18b. The planet, which is 124 light-years away, has been the focus of much attention since it was discovered in 2015 using the Kepler space telescope because it lies in the habitable zone around its red-dwarf star. Initial observations with Hubble indicated the presence of water vapor, and follow-up investigations using the James Webb Space Telescope detected all sorts of goodies in the atmosphere, including carbon dioxide and methane. But more recently, JWST saw signs of dimethyl sulfide (DMS) and dimethyl disulfide (DMDS), organic molecules which, on Earth, are strongly associated with biological processes in marine bacteria and phytoplankton.

The team analyzing the JWST data says that the data is currently pretty good, with a statistical significance of 99.7%. That’s a three-sigma result, and while it’s promising, it’s not quite good enough to seal the deal that life evolved more than once in the universe. If further JWST observations manage to firm that up to five sigma, it’ll be the most important scientific result of all time. To our way of thinking, it would be much more significant than finding evidence of ancient or even current life in our solar system, since cross-contamination is so easy in the relatively cozy confines of the Sun’s gravity well. K2-18b is far enough away from our system as to make that virtually impossible, and that would say a lot about the universality of biochemical evolution. It could also provide an answer to the Fermi Paradox, since it could indicate that the galaxy is actually teeming with life but under conditions that make it difficult to evolve into species capable of making detectable techno-signatures. It’s hard to build a radio or a rocket when you live on a high-g water world, after all.

Closer to home, there’s speculation that the famous Antikythera mechanism may not have worked at all in its heyday. According to researchers from Universidad Nacional de Mar del Plata in Argentina, “the world’s first analog computer” could not have worked due to the accumulated mechanical error of its gears. They blame this on the shape of the gear teeth, which appear triangular on CT scans of the mechanism, and which they seem to attribute to manufacturing defects. Given the 20-odd centuries the brass-and-iron device spent at the bottom of the Aegean Sea and the potential for artifacts in CT scans, we’re not sure it’s safe to pin the suboptimal shape of the gear teeth on the maker of the mechanism. They also seem to call into question the ability of 1st-century BCE craftsmen to construct a mechanism with sufficient precision to serve as a useful astronomical calculator, a position that Chris from Clickspring has been putting the lie to with his ongoing effort to reproduce the Antikythera mechanism using ancient tools and materials. We’re keen to hear what he has to say about this issue.

Speaking of questionable scientific papers, have you heard about “vegetative electron microscopy”? It’s all the rage, having been mentioned in at least 22 scientific papers recently, even though no such technique exists. Or rather, it didn’t exist until around 2017, when it popped up in a couple of Iranian scientific papers. How it came into being is a bit of a mystery, but it may have started with faulty scans of a paper from the 1950s, which had the terms “vegetative” and “electron microscopy” printed in different columns but directly across from each other. That somehow led to the terms getting glued together, possibly in one of those Iranian papers because the Farsi spelling of “vegetative” is very similar to “scanning,” a much more sensible prefix to “electron microscopy.” Once the nonsense term was created, it propagated into subsequent papers of dubious scientific provenance by authors who didn’t bother to check their references, or perhaps never existed in the first place. The wonders of our AI world never cease to amaze.

And finally, from the heart of Silicon Valley comes a tale of cyber hijinks as several crosswalks were hacked to taunt everyone’s favorite billionaires. Twelve Palo Alto crosswalks were targeted by persons unknown, who somehow managed to gain access to the voice announcement system in the crosswalks and replaced the normally helpful voice messages with deep-fake audio of Elon Musk and Mark Zuckerberg saying ridiculous but plausible things. Redwood City and Menlo Park crosswalks may have also been attacked, and soulless city officials responded by disabling the voice feature. We get why they had to do it, but as cyberattacks go, this one seems pretty harmless.

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Forth is popular on small computers because it is simple to implement, yet quite powerful. But what happens when you really need to shrink it? Well, if your target is the 6502, there’s milliForth-6502.

This is a port of milliForth, which is a fork of sectorforth. The sectorforth project set the standard, implementing a Forth so small it could fit in a 512-byte boot sector. The milliForth project took sectorforth and made it even smaller, weighing in at only 336 bytes. However, both milliForth and sectorforth are for the x86 architecture. With milliForth-6502, [Alvaro G. S. Barcellos] wanted to see how small he could make a 6502 implementation.

So how big is the milliForth-6502 binary? Our tests indicate: 1,110 bytes. It won’t quite fit in a boot sector, but it’s pretty small!

Most of the code for milliForth-6502 is assembly code in sector-6502.s. This code is compiled using tools from the cc65 project. To run the code lib6502 is used for 6502 emulation.

Emulation is all well and good as far as it goes, especially for development and testing, but we’d love to see this code running on a real 6502. Even better would be a 6502 built from scratch! If you get this code running we’d love to hear how it went!

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hackaday.com/2025/04/20/millif…

Le e-mail interne inviate dai dipendenti di Snapchat, la popolare app di messaggistica fotografica e video, dimostrano che l’azienda ha deliberatamente danneggiato adolescenti e giovani adulti, ovvero il pubblico a cui si rivolge.

Lo psicologo sociale e autore del best-seller Generation Anxious Jonathan Haidt ha pubblicato la scorsa settimana un articolo su Substack in cui detto che Snap Inc. riceve ogni mese migliaia di segnalazioni di “sextortion”, ovvero estorsione sessuale.

Insieme al ricercatore Zach Rush, ha presentato decine di estratti da rapporti interni, studi, e-mail e dichiarazioni pubbliche in cui i dipendenti e i consulenti di Snap riconoscono che Snapchat danneggia i minori. Secondo gli autori, queste confessioni possono essere raggruppate in cinque aree: uso compulsivo, accesso a droghe e armi, distribuzione di materiale pedopornografico e casi di rapporti intimi forzati, cyberbullismo e consapevolezza di danni e violazioni dell’età senza azioni appropriate da parte dell’azienda.

Così come nel caso Per quanto riguarda TikTok, Haidt e Rush affermano che i dipendenti di Snap erano ben consapevoli della portata del problema, ma non stavano adottando le misure necessarie. Alcune di queste problematiche sono note da tempo, come la funzione “streak“, che conta il numero di giorni consecutivi in ​​cui gli utenti condividono foto.

Ciò crea un falso senso di impegno e attaccamento negli adolescenti, e la perdita di questo “lato positivo” può essere percepita quasi come la perdita di un’amicizia. Allo stesso tempo, l’applicazione in sé rimane un mezzo di comunicazione superficiale: non garantisce un contatto reale e non sostituisce l’interazione dal vivo.

È noto che molti ex dirigenti di colossi della tecnologia, tra cui quelli che hanno partecipato alle riprese del documentario “The Social Dilemma“, non permettono ai propri figli di utilizzare gli smartphone. Sanno fin troppo bene cosa devono affrontare gli utenti, soprattutto quelli più giovani.

E se gli inventori di questi sistemi si rifiutano di affidarli ai propri figli, perché dovrebbero farlo i genitori comuni?

Gli autori del rapporto ritengono che sia giunto il momento di avviare una riflessione seria sulla dipendenza digitale e sulla responsabilità delle aziende tecnologiche.

Forse, con l’aumento delle cause legali e il cambiamento dell’opinione pubblica, più persone inizieranno a considerare il prezzo che pagano per essere costantemente presenti nel mondo digitale.

L'articolo Snapchat sapeva tutto: come l’app ha danneggiato milioni di adolescenti proviene da il blog della sicurezza informatica.

Despite the best efforts of the RepRap community over the last twenty years, self-replicating 3D printers have remained a stubbornly elusive goal, largely due to the difficulty of printing electronics. [Brian Minnick]’s fully-printed 3D printer could eventually change that, and he’s already solved an impressive number of technical challenges in the process.

[Brian]’s first step was to make a 3D-printable motor. Instead of the more conventional stepper motors, he designed a fully 3D-printed 3-pole brushed motor. The motor coils are made from solder paste, which the printer applies using a custom syringe-based extruder. The paste is then sintered at a moderate temperature, resulting in traces with a resistivity as low as 0.001 Ω mm, low enough to make effective magnetic coils.

Brushed motors are less accurate than stepper motors, but they do have a particularly useful advantage here: their speed can be controlled simply by varying the voltage. This enables a purely electromechanical control system – no microcontroller on this printer! A 3D-printed data strip encodes instructions for the printer as holes in a plastic sheet, which open and close simple switches in the motor controller. These switches control the speed, direction, and duration of the motors’ movement, letting the data strip encode motion vectors.

Remarkably, the hotend on this printer is also 3D-printed. [Brian] took advantage of the fact that PEEK’s melting point increases by about 110 ℃ when it’s annealed, which should allow an annealed hotend to print itself. So far it’s only extruded PLA, but the idea seems sound.

The video below the break shows a single-axis proof of concept in action. We haven’t been able to find any documentation of a fully-functional 3D printer, but nevertheless, it’s an impressive demonstration. We’ve covered similar printers before, and if you make progress in this area, be sure to send us a tip.

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hackaday.com/2025/04/20/the-mo…

Entry-level oscilloscopes are a great way to get some low-cost instrumentation on a test bench, whether it’s for a garage lab or a schoolroom. But the cheapest ones are often cheap for a reason, and even though they work well for the price they won’t stand up to more advanced equipment. But missing features don’t have to stay missing forever, as it’s possible to augment them to get some of these features. [Tommy’s] project shows you one way to make a silk purse from a sow’s ear, at least as it relates to oscilloscopes.

Most of the problem with these lower-cost tools is their low precision due to fewer bits of analog-digital conversion. They also tend to be quite noisy, further lowering the quality of the oscilloscope. [Tommy] is focusing his efforts on the DSO138-mini, an oscilloscope with a bandwidth of 100 kHz and an effective resolution of 10 bits. The first step is to add an anti-aliasing filter to the input, which is essentially a low-pass filter that removes high frequency components of the signal, which could cause a problem due to the lower resolution of the device. After that, digital post-processing is done on the output, which removes noise caused by the system’s power supply, among other things, and essentially acts as a second low-pass filter.

In part 2 of the project, [Tommy] demonstrates the effectiveness of these two methods with experimental data, showing that a good percentage of the noise on a test signal has been removed from the output. All the more impressive here is that the only additional cost besides the inexpensive oscilloscope itself is for a ceramic capacitor that costs around a dollar. We were also impressed: [Tommy] is a junior in high school!

Presumably, you could apply these techniques to other inexpensive equipment, like this even cheaper oscilloscope based on the ESP32.

hackaday.com/2025/04/20/low-co…

E buona Pasqua, riempiamoci la bocca di Pace.

Gli Usa avvertono, 'senza una svolta su Kiev ci sfiliamo'

Fonte: ANSA
search.app/dRKGm

Parlando del padre:

"Ha preferito il lager piuttosto che arrendersi al nazifascismo e combattere con i tedeschi contro gli italiani" – ha spiegato – "aveva fatto amicizia con un compagno che gli aveva salvato la vita. Si chiamava Vasco"

agi.it/spettacolo/news/2025-04…

Nella loro eleganza, i mici sono diventati discreti guardiani del parco, custodi ideali di un passato che ancora parla.

agi.it/cronaca/news/2025-04-19…

#gatti

Riporto dalla newsletter di Haaretz:

The New York Times reported that the White House's antisemitism task force sent Harvard University its letter demanding reforms by mistake.

Ma perché l'estrema destra non riesce a non essere cialtrona? È una sua caratteristica genetica o hanno semplicemente la sfortuna di trovarsi leader cialtroni ad ogni latitudine?

A rendere la questione piuttosto complicata è il fatto che la terapia familiare è una pratica continuamente in cambiamento, la teoria sistemica applicata alla psicoterapia è da sempre costantemente in cerca di un modo per superarsi. Dalla sua alba questa pratica si è presentata come inquieta e instabile. Diversamente da quanto accade per altri approcci terapeutici, un sistemico che passasse qualche anno su un’isola deserta, al ritorno difficilmente troverebbe tutto come prima.
O almeno è stato così per una fetta importante della sua storia. Questo si deve, credo, a due ragioni soprattutto...

Dal mio blog di psicoterapia:
massimogiuliani.it/blog/2025/0…

Cosa si insegna e, soprattutto, cosa no (nuove note su integrazioni ed eclettismi) - Corpi che parlano, il blog

"La terapia familiare ha senza dubbio cambiato notevolmente le pratiche di salute mentale, ma in qualche modo ha perso per strada gran parte dell'antica eccitazione (...) Che ne è stato di quell'idea straordinariamente nuova, di quell'audace salto

^{massimo giuliani (Corpi che parlano, il blog)}

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Diego Herculano

2025-04-17 12:55:16

China

@photography@lemmy.ml
#photography #photo #streetphotography #fotografia #China #360Degrees #35mm #art #travel #press #news #photooftheday #mastodon #PortfolioDay #pixelfed #photojournalism #photodocumentary #beach