airbreather (u/airbreather)

airbreather commented on High-Altitude Adventure with a DIY Pico Balloon spectrum.ieee.org/explore... · Posted by u/jnord

airbreather · 5 days ago

Isn't H2 better because better lift and being a molecule of two hydrogen atoms it is not quite as slippery as helium and quite easy to make?

From wikipedia "lifting gas"

"Helium is the second lightest gas (0.1786 g/L, 14% the density of air, at STP). For that reason, it is an attractive gas for lifting as well.

A major advantage is that this gas is noncombustible. But the use of helium has some disadvantages, too:

    The diffusion issue shared with hydrogen (though, as helium's molecular radius, 138 pm, is smaller, it diffuses through more materials than hydrogen[4])."

airbreather commented on Automatic Programming antirez.com/news/159... · Posted by u/dvrp

motoboi · 9 days ago

We maybe witnessing the last generation of master software artisans like antirez.

This is beautiful to see, their mastery harnessing the power of the intelligent machine tools to design, understand and build.

This is like seeing a master of image & light like michelangelo receiving a camera, photoshop and a printer. It's an exponential elevation of the art.

But to become a master like michelangelo one had to dedicate herself to the craft of manually mixing and applying materials to bend and modulate light, slowly building and consolidating those neural pathways by reflection and, most of all, practice, until those skills became as natural as getting up or bringing a hand to the mouth. When that happened, art flowed from her mind to the physical world and the body became the vessel of intuition.

A master like antirez had to wrap his head around concepts alien to the human mind. Bits, bytes, arrays, memory layout, processors, compilers, interfaces, abstractions, constraints, types, concurrency do not exist in the savannas that forged brains. Had to comprehend and learn to use his own cognitive capabilities and restrictions to know at what level to break the code units and the abstraction boundaries. At the very top, master this in a level so high that software became like Redis: beautiful, powerful and so elevated in the art that it became simpler, not more complex. It's Picasso drawing a dog.

The intelligent software building machines can do things no human manually can (given the same time, humans die, get old or get bored), but they are not brush and canvas. They function in another way, the mind needs other paths to master them. The path to master them is not the same path to master artisanal software building.

So, this new generation, wanting to build things not possible to the artisan, will become masters of another craft, one we right now cannot even comprehend or imagine, in the same way michelangelo could never imagine the level of control over light the modern photography masters have.

Me, not a master, but having dedicated my whole life to artisanal software building, am excited to receive and use the new tools, to experiment the new craft. Also frightened by the uncertainty of this new world.

What a time to be alive.

airbreather · 8 days ago

The true art is in the architecture, which is the bit humans still generally control, not the tiny details.

Unless you would rather be a calligrapher than a novelist.

airbreather commented on Automatic Programming antirez.com/news/159... · Posted by u/dvrp

catdog · 10 days ago

> The key phrase here is “requirements analysis” and if you’re not good at it either your software sucks or you’re going to iterate needlessly and waste massive time including on bad architecture. You don’t iterate the foundation of a house.

This depends heavily on the kind of problem you are trying to solve. In a lot of cases requirements are not fixed but evolve over time, either reacting to changes in the real word environment or by just realizing things which are nice in theory are not working out in practice.

You don’t iterate the foundation of a house because we have done it enough times and also the environment the house exists in (geography, climate, ...) is usually not expected to change much. If that were the case we would certainly build houses differently than we usually do.

airbreather · 8 days ago

The key first step here is "Problem Identification" - the number of times I have seen where it is part way through a development, and only then it starts to become obvious that even if the specifications were good, they were not solving the right problem.

Users have a habit of describing their problem as the solution they think they would like to have, often being disastrously far from the actual need.

airbreather commented on Automatic Programming antirez.com/news/159... · Posted by u/dvrp

manmal · 9 days ago

My experience is that such one-shotted projects never survive the collision with reality. Even with extremely detailed specs, the end result will not be what people had in mind, because human minds cannot fully anticipate the complexity of software, and all the edge cases it needs to handle. "Oh, I didn't think that this scheduled alarm is super annoying, I'd actually expect this other alarm to supersede it. It's great we've built this prototype, because this was hard to anticipate on paper."

I'm not saying I don't believe your report - maybe you are working in a domain where everything is super deterministic. Anyway, I don't.

airbreather · 8 days ago

Most people do not believe it is possible to fully specify software before writing it, until they are forced to.

Having part of my background in Functional Safety, I have seen it done many times, and it can most definitely be done.

It is just it can't be done in the sort of time frames that people who do not specify before coding, are used to.

But, if you can't afford to move fast and break tings, because it is an airplane, or train signaling system, or complicated elevator system with multiple cars in the same shaft, then you generally write no code until you know exactly what you want the code to do (and more importantly, not do).

airbreather commented on Automatic Programming antirez.com/news/159... · Posted by u/dvrp

airbreather · 8 days ago

Nothing has changed, it is just now, more than ever, specification is everything.

It is just that for some decades now it was possible to get away with poor or lacking specification, by continually incrementing by sprints, or pivoting, or whatever.

But, back in the day when systems analysts were still a person with very particular skills that might never code, specification was everything.

And now, the wheel turns, and the importance of good specification appears to be the defining factor once again, all of a sudden.

airbreather commented on Time Station Emulator github.com/kangtastic/tim... · Posted by u/FriedPickles

airbreather · 13 days ago

check out this guy, doing something similar sending Lora packets without a radio - https://youtu.be/eIdHBDSQHyw?si=MGteEp72Mz52qNqu

"This video explores LoRaWAN communication using a microcontroller without a dedicated radio chip. CNLohr demonstrates techniques to transmit LoRa packets over surprisingly long distances, pushing the limits of inexpensive hardware. The project involves creative software and hardware interaction to generate signals at unexpected frequencies."

airbreather commented on Why did we use leaded petrol for so long? (2017) bbc.com/news/business-405... · Posted by u/simonebrunozzi

airbreather · 2 months ago

we still do for light aviation

airbreather commented on How to build a solar powered electric oven solar.lowtechmagazine.com... · Posted by u/surprisetalk

kragen · 3 months ago

Some design alternatives:

• Use lime cement rather than portland cement for the mortar. Portland will be damaged over time by the 120° temperature and may spall explosively, causing injury, particularly if you embed nichrome heating elements in it.

• Similarly, don't use plaster of Paris inside the oven. It will also degrade over time at that temperature. Waterglass would work to fix tiles to wood but will foam up when heated if not crosslinked with polyvalent cations from, for example, chalk or iron oxide. Premixed refractory adhesives of this recipe are available from hardware stores in most countries.

• Use insulating fired-clay ceramic rather than cork or wool for insulation. It will need to be thicker but will not outgas volatile organic compounds into your food or degrade over time. Fireclay is not needed for this application; any normal pottery clay body should work. I used a ball clay body. Mix wet organic waste into the clay body at ratios between 1 and 3 parts organics to 1 part clay body before forming bricks and firing in an oxidizing atmosphere. The organics burn out in the kiln, which smells like hell during the firing. Suitable organic wastes include used yerba mate, used coffee grounds, cow manure, or sawdust made from untreated wood.

• Vermiculite or perlite from the garden store is another safe insulation option. A minimal amount of waterglass can hold it in place.

• Similarly, don't use chipboard (OSB) for the oven structure, as suggested in the article. It outgasses when hot, which it will be if you drape a blanket over the oven, as also suggested in the article. A very common type outgasses formaldehyde, which will condense in your food. You don't want to be eating formaldehyde for years. Similarly for most other composite wood products such as particle board and MDF, which at least the article does not specifically recommend. Masonite (high density fiberboard) should theoretically be fine, but I wouldn't risk it.

• Similarly, don't use hot glue as suggested in the article to attach the insulation. It's normally EVA with additives, but isn't specified for continuous operation close to its melting point, and might also outgas things you don't want condensing in your food for hours every day. I'd even be wary of wood glue. Waterglass with a polyvalent cation source should be fine.

• Mortar is porous, so if you want to be able to clean food off of mortar joints between tiles inside the oven, maybe seal it with waterglass. "Grout" is underspecified. You want a material that is food-safe at cooking temperatures; you don't want to go years eating whatever antifungal additives and plasticizers are in hardware-store grout for your bathroom floor, volatilized by oven heat.

• Electric cooking appliances should always include a thermal cutout device for minimal safety. These are cheap and available worldwide including by salvaging them from broken microwave ovens or electric kettles. They're very simple to use. No excuses. (This is mentioned in the "manual" as a "thermal switch", but only as an option, and not in the article.)

• Normally, high-temperature electrical connections should not be soldered as the "manual" suggests doing; they should use crimped or spring connections. Regular 63/37 electronics solder melts at 183°, which the oven as a whole might reach and which the nichrome could easily reach. It also contains lead, which is probably okay in an oven but seems a bit questionable to me, especially embedded inside mortar.

• Alternative methods of thermal energy storage and release seem like they might be worthwhile for this application, in order to lose less energy when not cooking, and in order to sustain an ideal cooking temperature for longer when cooking. Sensible heat storage like this has the disadvantage of constantly losing heat, which is an enormous disadvantage if the appliance is in your kitchen in a hot climate. Phase-change energy storage might be applicable, but I'm not sure what material melts in the right temperature range. TCES is probably applicable, but would need some design work. For example, plaster of Paris heats up to a usable oven temperature when hydrated, but keeping it from coalescing into a solid mass that is difficult to re-dehydrate conveniently. Phase-change or TCES materials might be portable enough to leave out on your balcony or roof terrace until it's time to cook—carrying them inside is not quite as convenient as flipping a switch, but it's far from the same level of hassle as building a wood fire.

• Storing sensible heat in a much thicker brick through which you can later circulate air might be another alternative, like electric night storage heaters. This would probably require a metal fan, but the amount of battery storage required to power the fan is minuscule compared to the amount you would require to power an electric heating element.

One correction. The article says, "In contrast, an ISEC can be insulated on all sides, making it more energy efficient than a non-electric solar box cooker." This is arrant nonsense. Non-electric solar box cookers are typically over 50% efficient; retail solar photovoltaic panels are at best 24% efficient, so the efficiency of a solar cooking system that uses a retail PV module to capture sunlight is at best 24% minus the heat leakage through the insulation. (But to me it seems like nonsense to worry about efficiency in a context like this, since sunlight is free.)

Kris de Decker has an established practice of ignoring or denying indisputable factual errors like this when they are pointed out to him, so I fully expect this article to also remain permanently in error. I'd be delighted if he proved me wrong on this.

airbreather · 3 months ago

yes, perlite is the insulation of choice, as long as you keep it dry, very few things surpass it.

airbreather commented on Things you can do with diodes lcamtuf.substack.com/p/th... · Posted by u/zdw

airbreather · 3 months ago

before silicon, rectification was often achieved with copper oxide

airbreather commented on I made a 10¢ MCU Talk atomic14.com/2025/10/29/C... · Posted by u/iamflimflam1

airbreather · 3 months ago

Have you tried just savimg the zero crossing times?

From distant memory you got quite a bit more compaction.