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Cake day: June 5th, 2023

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  • Yeah, that was just badly worded. Didn’t really think it through either. Let me clarify.

    You don’t want to spin the wheel too fast, because that’s going to make people sick. To get around that problem, you need to compensate by making the wheel bigger. More specifically, it should be hundreds of meters in diameter. That means it’s going to require a lot of construction materials, and that gets really expensive to build and even more expensive to deliver.

    Normally, space things are built to be as light as possible. Building stuff out of thin aluminium, magnesium, titanium and carbon fiber just won’t be good enough unless you make those structures thicker. The materials are good enough though. If you could launch stuff up there for free, you might as well use steel cables and they would be strong enough.

    Nevertheless, it’s still a pressurised donut, and that puts a lot of stress on all the parts, which means you can’t build it out of paper thin titanium. The rotation is totally fine by comparison, since that doesn’t add too much to the stresses.



  • There are ways to cheat though. For example, spinning things can produce the sensation of being in gravity. Spinning stations would face immense tension forces, which make it difficult to find suitable materials to build them out of. Also, those materials need to be lifted up to orbit, so heavy materials won’t do.

    See also: 2001: A Space Odyssey

    Another option would be constant acceleration, like in The Expanse. Definitely not a very viable option right now as modern rocket fuels still suck. It could take a while to fix this one.

    If you want to be extra cheesy, you just have to make your space station as massive as the Earth, and you’ll get plenty enough gravity. There’s an even cheesier shortcut. Just start calling earth your new space station.







  • Dangers like that can be identified quite easily. It’s a qualitative thing, and qualitative chemistry is pretty robust. For instance, we can say that there’s a risk that a particular reaction will produce hydrogen under specific circumstances. We’ll just build the plant accordingly instead of trusting that we can always operate the plant correctly. Sooner or later, you’ll end up running the plant in the wrong way, and you’ll produce some hydrogen, so it’s good to have a plant that can detect and deal with it safely.

    However, usually the idea is to produce something entirely different, and do so efficiently. Those sorts of questions are quantitative, and that’s where things can and will go wrong all the time. Like, how do you ensure that your expensive catalyst isn’t covered in goo, or corrosion doesn’t eat your fancy impeller? How do you ensure that the amount of impurities in the product will remain reasonably low? It’s all about the quantities and reaction rates, and that’s the hard part with inorganic chemistry.


  • Inorganic chemistry is fairly simple and fun as long as you keep it in the lab. Industrial-scale inorganic chemistry gets ridiculously complicated because all the reactants and products are complicated and messy. Also, a large reactor will have all sorts of gradients, which means that the reactions take place in unfavourable conditions all the time. None of it is ideal, and none of it follows simplified laws or rules very well.

    Sure, we have all sorts of fancy calculations, but none of them predict very accurately what’s going to happen and when. Even the best models and theories give approximate and crude answers when you’re dealing with messy industrial-scale chemistry.

    Models give you a rough idea, lab experiments give you a decent idea, but running the process at full scale is the only way to find out exactly how those reactions really work in real life.

    Turns out, our theories are too simple to handle complicated solutions. They can predict the behaviour of simple solutions very well, but that’s not good enough. In real life, you rarely have well behaved clean reagents.