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Cake day: June 11th, 2023

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  • But the mining, milling, and production of nuclear fuel, as well as the construction and decommissioning of nuclear plants, emit greenhouse gases at levels ranging from 10 to 130 grams of carbon dioxide per kilowatt hour of power — lower than fossil fuels but higher than wind and hydroelectricity (and roughly on par with solar).

    That’s interesting. The article they link gives a bit more detail:

    These energy intensities translate into greenhouse gas intensities for LWR and HWR of between 10 and 130 g CO2-e/kWhel, with an average of 65 g CO2-e/kWhel.

    While these greenhouse gases are expectedly lower than those of fossil technologies (typically 600–1200 g CO2-e/kWhel), they are higher than reported figures for wind turbines and hydroelectricity (around 15–25 g CO2-e/kWhel) and in the order of, or slightly lower than, solar photovoltaic or solar thermal power (around 90 g CO2-e/kWhel).

    The wide range for nuclear apparently comes from difficulties in estimating the carbon footprint of mining/processing the uranium, but that nuclear is sort of in the middle of the pack in carbon footprint relative to renewables in spite of the fueling costs is good to know.

    I suppose these sort of numbers may change dramatically in years to come. Take solar. A lot of focus seems to be on the efficiency of panels, which would almost certainly lower the carbon cost per unit of energy as it improves, but a breakthrough in panel longevity would also do that in an amortized emissions sort of way.


  • The thing about the MPW Shell is it was sort of the only game in town if you actually wanted a command line with the classic Mac OS. (There’s an awesome little emulator called SheepShaver if you ever want to explore it btw.) Well, I suppose there was A/UX. I thought it was a miracle when that came out. You have to realize in those early days a good chunk of the operating system itself was actually baked in to ROM. (You had to do desperate things to squeeze a GUI out of such limited resources as existed back then!) So to this day I have no idea how they managed to spin off a 'nix despite that.

    Anyways. I wonder, if you made some sort of template format today, to what extent you could write some sort of conversion tool that would scrape a man page or whatever to rough it in and then you could tweak it to get what you want? man pages aren’t super standardized in their format I guess, so it’s probably more trouble than it’s worth. I like to use Python’s argparse when rolling out scripts myself, and its --help format is pretty rigid given that it’s algorithmically generated. Might be more plausible with something like that? I had a quick look just now to see if you can drill down into the argparse.ArgumentParser class itself to pull out the info more directly, but it seems a rather opaque thing that doesn’t expose public APIs for that. Oh well…


  • This reminds me of something from my ancient past. Back in the early-ish days of Apple, there was a development system called MPW (Macintosh Programmer’s Workshop) which included its own little kludgy shell.

    The weird thing about it though was while you could enter commands on the command line like in any shell, you could prefix them with the word commando (presumably a portmanteau of “command” and “window”) and this window would pop up showing various buttons, checkboxes, etc. correponding to command line options. When you ok’d the window, it would generate the command line for you.

    I’m rather hazy about how all this worked, but I think there was some sort of template language to define the window layout if you wanted to add commando support for your own tool? And presumeably, as you say, you could restrict what’s possible with the window interface as you deemed fit?


  • You can always combine integer operations in smaller chunks to simulate something that’s too big to fit in a register. Python even does this transparently for you, so your integers can be as big as you want.

    The fundamental problem that led to requiring 64-bit was when we needed to start addressing more than 4 GB of RAM. It’s kind of similar to the problem of the Internet, where 4 billion unique IP addresses falls rather short of what we need. IPv6 has a host of improvements, but the massively improved address space is what gets talked about the most since that’s what is desperately needed.

    Going back to RAM though, it’s sort of interesting that at the lowest levels of accessing memory, it is done in chunks that are larger than 8 bits, and that’s been the case for a long time now. CPUs have to provide the illusion that an 8-bit byte is the smallest addressible unit of memory since software would break badly were this not the case, but it’s somewhat amusing to me that we still shouldn’t really need more than 32 bits to address RAM at the lowest levels even with the 16 GB I have in my laptop right now. I’ve worked with 32-bit microcontrollers where the byte size is > 8 bits, and yeah, you can have plenty of addressible memory in there if you wanted.





  • I have some vague recollection of a hacker convention from the 90s where people were challenged to come up with wireless networking in a one night coding marathon. (This was long before wifi.) So some dude used speech synthesis to get a machine to say “one zero one one zero…” and another to assemble the binary data into packets using speech recognition. It was hilarious, and the dev had to keep telling people to shut up and stop laughing so he could complete the demo.

    But anyways… what I’m trying to suggest here is you might have the best luck if your notification sounds contain spoken commands and you use speech recognition to trigger scripts? That tech is pretty mature at this point.






  • Ok, I actually tried something like this at a terminal. You do still need the -C ./testar if you use the subshell since tar won’t know where to look otherwise.

    (sudo cd ./testar && sudo find . -maxdepth 1 -type d,f)  | sudo tar -czvf ./xtractar/tar2/testbackup2.tgz -C ./testar -T -
    

    This will still give you a listing with ./text.tz and so on because find prints ./whatever when you search .. I think this is harmless? But I suppose you could remove them if it bothers you.

    (sudo cd ./testar && sudo find . -maxdepth 1 -type d,f)  | cut -c3- | sudo tar -czvf ./xtractar/tar2/testbackup2.tgz -C ./testar -T -
    




  • I treat self-checkout as a game with 2 goals:

    1. Make it through the process without getting any help.
    2. Do it as fast as a trained cashier.

    In a good season, my batting average for #1 might be .300, which would not be bad were the game baseball. As far as #2 is concerned, I have never come close. It’s like I throw 30 mph pitches. Things get real when I’m trying to look up bananas or something and the helper comes up behind me. “It’s 4198. Here, let me do it.” Thanks, I already lost #2 and you just made me lose #1…again.



  • I am also fairly new to the game. I had an iMac from around 2010 that was starting to show its age. Newer macOS versions were glacial on it. I eventually realized they were meant to boot off SSDs, but my options in that regard weren’t great. I would either have to take the whole thing apart to replace the internal drive or live with USB2 speeds on an external SSD. Then it dawned on me I could just put Ubuntu on there and call it a day. This worked great and bought me a few more years out of that machine.

    More recently, we started buying threadripper workstations at the office for scientific modelling. These have since migrated into a server room where they are currently acting as a small compute cluster.

    And most recently, I’ve been tinkering around a bit on my Steam Deck. It’s a little walled-garden-ish but it let me put VSCode and a few tools on there so I’m playing around.


  • Ok, so we’re onto capacitors and fuel cells now. Here we go with my mental image of those.

    On the pros side, capacitors can charge/discharge in an instant, have nearly perfect energy recovery (almost everything you put in comes back out), and have almost limitless charging cycles with no memory effects or any of that nonsense. On the cons side, even a supercapacitor can’t match battery tech for energy storage density and they tend to be not so great for long-term electrical storage.

    Fuel cells are sort of the opposite. Once you’ve sorted out the challenges in producing/storing/transporting hydrogen (these are all non-trivial but not necessarily deal-breakers either?), you’re looking at essentially limitless storage duration since it’s, well, a fuel. Like you can stockpile it for next year. The energy density is enviably high, though with pure hydrogen, you’re doing better by weight than by volume. In any case though, it’s looking pretty good compared to batteries.

    But pulling the energy out of them in a timely manner is a major pain. You need either a chemical or thermal catalyst to speed it along for most applications. And the chemical of choice is platinum, which is not exactly abundant. If you wanted a fuel cell in every car, is there even enough on Earth for that? I’m not so sure.

    Also, I have read impurities in the fuel can really mess up this type of fuel cell. The thermal type is purportedly more forgiving in this respect, though I picture thermal fuel cells as these hulking things that would work best as stationary power plants? Well, maybe they would be a good fit for large ships? It’s hard to picture some giant container vessel plying the oceans on battery power, at any rate.