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Cake day: 2023年6月10日

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  • I think you may be mixing up Project Orion (let’s chuck bombs out of the back to make us go zoom) with NERVA (a nuclear thermal rocket engine where the heat from chemical reactions is replaced with heat from a nuclear reactor to generate gas expansion out of a nozzle). Something like NERVA is actually a great idea. Let me tell you why!

    • It’s completely clean (unlike Orion and fission-fragment rockets)

      • the reactor and fuel never touch, the fuel goes through a heat exchanger and is not radioactive
    • it provides extremely high efficiency

      • chemical rockets top out at ~400-500 isp in vacuum
      • NERVA tests in 1978 gave a vacuum isp of 841
      • ion thrusters like NEXT has an isp of 4170
    • it provides lots of thrust

      • NERVA had 246kN of thrust
      • NEXT (which was used on the DART mission) is 237 millinewtons
      • That’s 6 orders of magnitude more thrust!
    • No oxidizer is needed

      • All you need is reaction mass, just like ion thrusters

    For automated probes, the extreme efficiency and low thrust of ion thrusters makes perfect sense. If we ever want to send squishy humans further afield, we need something with more thrust so we can have shorter transit times (radiation is a bastard). Musk is supposedly going to Mars with Starship, and the Raptor engine is a marvel of engineering. I don’t like the man and I’m not confident that he’ll actually follow through with his plan, but the engineers at SpaceX are doing some crazy shit that might make it happen.

    Just think though, if the engine was literally twice as efficient and they didn’t need to lug around a tank of oxidizer, how much time could they shave off their transit? How much more could they send to Mars? Plus, they could potentially reduce the number of big-ass rockets they have to launch from Earth to refuel. If you can ISRU methane, then I imagine you could probably get hydrogen.

    There are problems that still need to be resolved (the first that comes to mind is how to deal with cryogenic hydrogen boiling off), but like, the US had a nuclear thermal engine in the 70s. It was approved for use in space, but congress cut funding after the space race concluded so it never flew.

    I’m happy to see that NASA is once again researching nuclear thermal rockets. Maybe we’ll get somewhere this time.



  • People who eat Dayton-style pizza are like the city of Dayton itself—smelly inside and bereft of true purpose. Those of us in the US who haven’t been so psychically damaged wouldn’t eat that shit.

    (I’m only just learning about the disgusting gutter pizza. I don’t like Dayton because my last company was slowly destroyed over several years by a company that was headquartered in Dayton. I associate the city with the asshole who was CEO. Fuck you, Chris! I’ve heard Dayton is, at worst, not great, so take my comment as the joke it is.)


  • Badabinski@kbin.socialtoSelfhosted@lemmy.worldPost your Servernames!
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    2 个月前

    I just kinda vaguely name them after what they do and how big they are:

    smol: my tiny little 2 bay Synology NAS that I’m no longer using
    medium: my R620 with 4x 18TB drives that is my current NAS (medium, because it’s larger than my previous NAS). Is also a k3s worker and provides NFS PVCs.
    big: my old full-tower gaming rig that’s a k3s worker and runs my Home Assistant VM
    molecule: my current mini-ITX gaming rig and primary computer, also serves as the k3s master node and runs a lot of my home automation stuff. I think I picked molecule because it’s REALLY tiny (it’s in a Dan Cases A4v2, I think?) and it has a bunch of small stuff running on it (containers and pods)
    monolith: my old T440p laptop. It’s a large, black, featureless slab that doesn’t do much
    slab: my new Framework 13 laptop. I just kinda looked at it and said, “that’s a nice slab of metal”

    All of the above running Linux. I tinkered with Ubuntu for the NAS (because I heard Ubuntu was good at ZFS), but I still absolutely hate Ubuntu, so it’s all Arch Linux.


  • For Linux applications that respect XDG? Sure. There are plenty that don’t because they either predate that specification, or they just don’t care. Linux filesystems are generally much faster at executing reads on many small files, meaning fast search tools like ripgrep and fd make it so I don’t really have to care. They’ll run through my whole $HOME in 5 seconds flat. There’s also stuff like locate, although I don’t like maintaining an index. SSDs are so damn fast that I can just rg --hidden --glob '*.toml' 'the_setting_i_want_to_change' ~/ whenever I want.


  • Eating this stuff would be about as bad as eating any regular cat litter that uses Fuller’s earth as the primary absorbent. The extra special ingredient (powdered quartz) is effectively nontoxic when ingested. The real issue is the chronic exposure to very fine silica dust.

    Edit: to clarify, I do not believe that it would be safe for humans or animals to use this as cat litter. Just realized that this comment might have been taken as a “well akshually it’s fine.” It is not fine, silicosis is a dreadful condition.


  • So I’d like to chime in. It looks the the two primary ingredients for ZEP-o-zorb are Fuller’s earth and powdered quartz.

    First, Fuller’s earth. This is good stuff! It’s actually often used as an industrial absorbent for chemical spills (the purpose of ZEP-o-zorb), as well as in some types of cat litter. It totally makes sense why this stuff would work well for you, and I understand why you’ve been using it for a year. It’s perfect for the task and has basically no downsides.

    Now, about the powdered quartz… Chemically known as silicon dioxide. It’s often refered to as silica. Silica is also good stuff! It’s in concrete, it’s the main component of glass, and of particular interest for your application, it’s very good at absorbing volatile organic smelly stuff. Seems perfect, right?

    Unfortunately, powdered quartz has a downside. When it’s in a very fine powder, it produces a lot of dust. This silicon dioxide dust is incredibly harmful to your lungs. Long-term exposure to silicon dioxide dust results in silicosis, which is a really serious illness that kills tens of thousands of people every year. Inhaling that dust can also give you lung cancer, lupus, rheumatoid arthritis, or other autoimmune disorders.

    I totally understand why you felt that this product was a great option! I don’t doubt that it serves as an absolutely excellent cat litter. I had two kitties that took the smelliest shits, and I was always searching for ways to fix that (either through diet, litter, stress reduction, or other things). I also understand how upsetting it can be to share something with people and be met with disbelief, denial, and accusations. However, I really want to urge you to look past all of that and reconsider your use of this product. The silica dust is practically invisible and tasteless, and it had the chance to cause you many years of problems. You and your cat deserve to be healthy.



  • I tip 20% or $5 on takeout orders, whatever is larger (provided nothing goes terribly wrong). I have the means, and I remember how much I fucking hated working in retail. I depend on these people to feed me and I appreciate that they’re willing to do it (especially with how poorly they get treated at times). If I can make someone’s day better then it’s worth it to me.

    That being said, I hate tip culture and wish that the laws in my country around tipping would change. This is getting off topic now (since I think that the people doing takeout orders aren’t subject to this), but it’s absurd that we let restraunts pay $3.50 an hour if someone is making the rest of the minimum wage in tips. If I tip someone, I want it to be because I really appreciate what they did. I don’t want to be paying their wages, they should be receiving a livable wage no matter what. I know that refusing to tip won’t change that, so I just go along with it.


  • I didn’t downvote those posts, but I did feel like the thread was aggressive when it didn’t need to be. I’d guess that a flippant/passive aggressive remark like “New to US civil law?” was (rightfully) upsetting to the user who clearly has an understanding of the law here. That user responded in kind and defended their original comment. However, they then kept responding to other users in a fairly aggressive fashion, even when those other users were communicating in alright way.

    I totally get it. I’d be pissed if, after posting a well reasoned and researched comment on Kubernetes, someone responded saying “new to container orchestration?” I try (and sometimes fail) to express the more vulnerable feelings underneath anger online after dealing with my anger in meatspace. I find it results in more productive conversations. It’s hard to do that, so I’m not casting aspersions. I think that’s probably why people downvoted in this case though. People try to suppress and avoid aggression and conflict because those things are uncomfortable and used to be precursors to actual physical danger. It’s just biology and emotions at work.




  • Sodium-ion batteries appear promising. Like, the energy density by weight of the current market offerings is absolutely too low to be useful for vehicles, but there’s hope that can be improved in a relatively short timescale. Prices should be pretty good when factories finish tooling up, and most chemistries use no rare earth metals. Current densities seem great for grid storage, which is where hydrogen has the most potential right now (imo).

    I still like the idea of hydrogen for some forms of transportation (freight trains, container ships, possibly aircraft if energy density could be increased or aircraft weight decreased somehow) and as a strategic emergency energy reserve. It’d be great to have more grid resilience as the environment continues to decay. I just worry about the energy costs that come with transporting hydrogen for cars and individual transport. Pipelines seem like they’d be challenging, and trucking it around seems a bit wasteful. In-situ generation would be ideal if power and water are available and hydrolysis can be made more efficient and compact, but that’s not possible everywhere.

    I dunno. I’m glad it’s not my job to figure out the actual energy cost of everything, but I’m really hoping grid-scale sodium-ion batteries will become a reality sooner rather than later, and that we’ll see sodium-ion batteries in cars within the next 10-15 years.


  • I think the OP clearly doesn’t like that they have this reaction (as someone else pointed out, and as you acknowledged). I think I understand why you might think this came from a lack of empathy. You like kids, what could be wrong with them acting like kids do? Sure, they’re loud, but it’s not that big of a deal! This person must have no empathy, because if they did, they’d be fine with it. People with no empathy are psychopaths, so OP must be a psychopath.

    I think you’re already starting to see what’s wrong with that line of reasoning, which I really appreciate. Just to restate it here, the OP probably doesn’t hate children, they just have problems with overstimulation (possibly misophonia or autism spectrum stuff). Not everyone has experienced overstimulation, but I can assure you that at best, it makes you reaaally cranky. Feelings of rage aren’t surprising to me. If the OP wants, there are coping strategies and things they can do to help themselves in certain circumstances, but they’re not wrong or bad. Their brain just works differently from other folks, and this is one of the effects of that.

    It’s not society’s job to fix this (because kids have the right to be kids, and kids are kinda loud sometimes, even if you’re trying to teach them to be mindful of their volume), but I think that it’s generally good to try and show some empathy, or at least ask questions in good faith if you don’t understand well enough to empathize.

    I’d implore you to communicate with a bit more intent. Calling someone a psychopath is a pretty serious thing to do! Did you intend to hurt someone’s feelings that much? Or were you just confused and a bit angry, and came to that conclusion in haste? There’s a person on the other side of this conversation who has feelings, and they’re asking here for help. They’re trying to improve themselves, and I don’t think you’d want to say that type of thing to someone who’s just trying to live a better life.


  • I’ve been incredibly happy with Kagi. All of the listicles and blogspam get shunted off into their own sections. Kagi also seems to do a pretty good job at finding “deep” results. Like, when I want to find out more information about some home automation gizmo, Kagi does a good job of finding some random blog post where someone has torn the gizmo apart and analyzed every strength and weakness it has. I still prefer Google for looking up restaurants and stuff, but I hardly use it anymore. I don’t at all regret the $10 a month I pay to use Kagi.

    Edit: I also like that Kagi lets you define rules. Occasionally I’ll be forced to go to Reddit to get some information (I really try to go elsewhere first). I deleted my account, so I go to new Reddit by default (which I hate). I don’t want to add an extension to redirect to old Reddit, but I can just replace the www with old automagically for all Reddit search results. Works great.