Badabinski

@Badabinski@kbin.social

• ⁨Comment⁩ on ⁨xkcd #2929: Good and Bad Ideas⁩ ⁨⁨6⁩ ⁨months⁩ ago⁩:

  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, 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 built 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.

• ⁨Comment⁩ on ⁨xkcd #2929: Good and Bad Ideas⁩ ⁨⁨6⁩ ⁨months⁩ ago⁩:

  There are many of these where I live. The lights are usually timed so that you just go straight through without having to stop. They're much better than the traditional intersections that came before.

  I will absolutely concede that they're shitty for pedestrians or cyclists, however.

• ⁨Comment⁩ on ⁨xkcd #2929: Good and Bad Ideas⁩ ⁨⁨6⁩ ⁨months⁩ ago⁩:

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

  (My last company was slowly destroyed over several years by a company that was headquartered in Dayton, so I associate the city with the asshole who was CEO. Fuck you, Chris!)

• ⁨Comment⁩ on ⁨If we can use hydrogen to power electric motors, why can’t we use water to run a car?⁩ ⁨⁨8⁩ ⁨months⁩ ago⁩:

  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. 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.

• ⁨Comment⁩ on ⁨How do I stop hating children?⁩ ⁨⁨10⁩ ⁨months⁩ ago⁩:

  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.