https://xkcd.com/2929

Alt text:

While it seemed like a fun prank at the time, I realize my prank fire extinguishers full of leaded gasoline were a mistake.

  • Wild_Mastic@lemmy.world
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    4 months ago

    So, about Project Orion from Wikipedia

    In August 1955, Ulam co-authored a classified paper proposing the use of nuclear fission bombs, “ejected and detonated at a considerable distance,” for propelling a vehicle in outer space.

    Excuse me what the fuck

    • Cethin@lemmy.zip
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      4 months ago

      All chemical propulsion is just controlled explosions that we use to push a thing forward. It’s not that different, as long as you don’t use it in the atmosphere or near humans.

      • Wild_Mastic@lemmy.world
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        4 months ago

        Yeah I know, it’s the same principle behind modern fuel engines. Still, using nukes for propelling something forward is a bit of a stretch.

        • notabot@lemm.ee
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          4 months ago

          Not just nukes, but nuclear shaped charges, at a rate of maybe one per second for a manned vehicle or even more for a faster cargo only mission.

          • Promethiel@lemmy.world
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            4 months ago

            If you can trust the human monkeys with the “shaping” of a rock that got us here, how you gonna distrust the widdle trivial matter of taking little bits of something and splitting them.

            It’s shaped charges, it’s totally fine and sane. I’d happily get on the 1,000th Orion flight*.

            *Only if that’s a fresh hull

    • SonnyVabitch@lemmy.world
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      4 months ago

      It’s not uncommon in scifi. Netflix’s Three Body Problem also explores such a solution in quite some depth.

      • jballs@sh.itjust.works
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        4 months ago

        I love The Three Body Problem, both the books and the show. But it bothered me to no end to read Netflix’s Three Body Problem.

        • SonnyVabitch@lemmy.world
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          4 months ago

          I’m not familiar with the books, and the plot summary of their Wikipedia article does not mention nuclear propulsion whereas the article for the series does, so I went with that.

          Unless what bothers you is the x followed by the apostrophe and the s, which I never know when to omit the s, so it is what it is.

          • jballs@sh.itjust.works
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            4 months ago

            Ah gotcha. Yeah you should check out the books if you’re liking the show! The books go into a ton more detail and the Staircase Project is pretty cool. Seeing it on the screen is cool too, but if you really wanna nerd out I highly recommend the books.

    • frezik@midwest.social
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      4 months ago

      It would probably work just fine, but it needs a huge ship. It could get up to a few percent of the speed of light.

      FWIW, nuclear test ban treaties are considered to outlaw it. I think we’re more likely to solve the technical difficulties of antimatter propulsion than we are to get over the political difficulties of nuclear bomb propulsion.

        • frezik@midwest.social
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          4 months ago

          Just as an observation, there was a time when everyone on the Internet was gaga over the idea of Project Orion, and you didn’t dare speak out against it lest you get a hail of downvotes.

          It’d work fine in deep space. It’s not a good idea to launch from Earth this way. But again, we’ll probably find something better once we’re at the stage of needing it.

            • frezik@midwest.social
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              4 months ago

              Implosion-type nukes are all but impossible to make go off that way. They need a whole bunch of small explosives to go off very precisely to squeeze the core in just the right way. A short circuit or a crash won’t have the necessary precision. This isn’t entirely safe, either–it can still cause a small explosion with a flash of fallout and radiation–but it’s a manageable problem.

              Gun-types (Little Boy was one) are easier to go off on accident, but the US retired its last gun-type design decades ago. I don’t think Russia used them much, either. They’re only good for smaller bombs, and their safety issues make them questionable for any use. Smaller nuclear powers aren’t bothering with them.

    • MonkderDritte@feddit.de
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      4 months ago

      Aren’t there plans again?

      Considering that you need huge shields and dampening and you only have the mass of the bomb itself as propelant, is it still as effective as controlled propulsion?

    • Evotech@lemmy.world
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      4 months ago

      I know right, I recently replaced my glasses with transition lenses and it’s pretty nice.

      Who doesn’t want automated sunglasses? Not seeing any downsides yet. Only thing I know they don’t work in cars, but I don’t generally drive so it’s ok

      The technology has come a long way since the 90s

      • wizardbeard@lemmy.dbzer0.com
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        4 months ago

        I find that they don’t “un-tint” when going inside fast enough for my liking, personally.

        Creates kind of the opposite effect of going from a dim room into a bright space. Instead of evrything seeming extra bright, it just dimmed everything and made it more difficult to see.

      • twice_twotimes@sh.itjust.works
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        4 months ago

        One problem my mom did not anticipate was that she would be stuck effectively wearing sunglasses for my brother’s outdoor wedding, where was sitting up with the bride and groom for the whole thing (Indian wedding). She just looked like an asshole, and continues to look like an asshole in the just about every photo of the ceremony. Oops.

      • surewhynotlem@lemmy.world
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        4 months ago

        In the cold they take too long to transition to clear. So you end up taking them off for a few seconds when you go inside. It’s only minorly annoying.

          • BearOfaTime@lemm.ee
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            4 months ago

            No, they don’t change inside (I’ve had them). They do have a slight tint all the time though, which isn’t a big deal.

          • ferret@sh.itjust.works
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            4 months ago

            The human brain is very good at smoothing over brightness differences, even an oppressively well lit office is still typically an order of magnitude dimmer than the sun.

  • FMT99@lemmy.world
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    4 months ago

    I was under the impression that bloodletting could in some cases actually be beneficial.

  • De_Narm@lemmy.world
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    4 months ago

    I think sliced bread is overrated as fuck. It used to be nice back when people couldn’t just buy knives for cheap, but nowadays it just means getting stale bread faster.

    • tiredofsametab@kbin.run
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      4 months ago

      For some types of bread, the machine can do it much more uniformly and without crushing. This can be difficult for humans.

    • biddy@feddit.nl
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      4 months ago

      But sliced bread has become something else that doesn’t exist with loaves. You can’t buy an unsliced loaf of ultra-processed white bread.

      • De_Narm@lemmy.world
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        4 months ago

        You can get a wide variety of both sliced and unsliced loaves in pretty much every supermarket in my area. The ultra-processed american type bread is something else entirely and it’s also a bad idea too, like pretty much all ultra-processed foods. Can that stuff even get stale? I remember it staying exactly the same up until it grows mold.

    • deegeese@sopuli.xyz
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      4 months ago

      For pan loaves, people store it in a plastic bag to keep the crust soft.

      Pan loaves should be presliced, stone baked loaves with thick crust should not.

  • yamanii@lemmy.world
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    4 months ago

    Every single glasses of mine have had transition lenses, I can’t imagine my life without them anymore.

        • Death_Equity@lemmy.world
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          4 months ago

          If you keep one eye closed and expose the other to sunlight, you can see the difference. The lenses tint a dark shade of purple. I have dark brown eyes, so you can’t really notice the difference easily. There is a purple ring that is most noticeable outside of the limbal ring. They don’t turn your eyes black like you had the tint of sunglasses or transitions glasses, which would be cool.

          I would imagine someone with lighter color eyes, like really light blue, would have a very noticeable difference.

          Something I did notice as the wearer is when the lenses are tinted there is like a contrast filter on your vision so colors look better.

        • Death_Equity@lemmy.world
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          4 months ago

          They kind of released under the radar because a comedy skit about them came out and gaslighted people into believing they were not a real thing.

          I only found them because I went to order contacts and saw the product category.

          They aren’t as good as sunglasses(but are really awesome) and they don’t work much in the car so you will still want sunglasses.

    • BearOfaTime@lemm.ee
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      4 months ago

      Transitions are game changing. Sounds like someone who doesn’t wear glasses all the time. I even had transition sunglasses before I needed glasses - got tired of taking them off going in/out all day.

      Not sure who created this (I kkow, XKCD), but it’s mediocre.

      Double-ended extension cords belongs in the top left right corner. Sounds bad and is bad.

      • AdrianTheFrog@lemmy.world
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        4 months ago

        Double-ended extension cords belongs in the top left right corner. Sounds bad and is bad.

        Remember, you’re probably more technical than the average person. Double ended extension chords sound fine if you haven’t heard of them before until you think about it for five seconds.

      • Encrypt-Keeper@lemmy.world
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        4 months ago

        I’ve worn glasses my entire adult life and I had to get rid of them because being half blind every time I transition from outside to inside was interfering with my job.

        • spikespaz@programming.dev
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          4 months ago

          This. I worked in a hardware store as a floater (I’m good at things, they ask me to do random) and often found myself irritated at how often I need to go outside for a minute to meet a customer or something, and then come back in and all the fucking lights are off.

      • limelight79@lemm.ee
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        4 months ago

        It might just be a joke. I use transitions in my cycling glasses, where I might be in shade or when it starts to get dark (but I’ll still have something protecting my eyes). I use regular sunglasses in the car, as transitions generally won’t work there.

      • Clbull@lemmy.world
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        4 months ago

        My only gripe with them is that if I spend any amount of time outdoors, even if it’s not actually sunny, my glasses quickly turn to shades.

    • RenBiv@lemmy.ml
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      4 months ago

      Coming inside and not being able to see a lot.

      I specifically got rid of them having had them in my last pair. Too annoying!

    • Lux@lemmy.blahaj.zone
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      4 months ago

      Diverging diamond interchanges are a type of road intersection that appears very chaotic from the outside, but are actually pretty simple and safe to navigate

      • eksb@programming.dev
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        4 months ago

        Diverging diamonds are great if your only consideration is car throughput.

        If you are considering people walking or riding bicycles, they are shit.

        • Oinks@lemmy.blahaj.zone
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          4 months ago

          It doesn’t help that US diverging diamonds seem to insist on having pedestrians walk through the median.

          But honestly all interchanges are varying degrees of horrible and if you want your city to be bearable to navigate as a pedestrian/cyclist you just really don’t want to do urban highways, or roads above a certain size in general.

        • Lux@lemmy.blahaj.zone
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          4 months ago

          I hadn’t considered that. I was still pretty car-brained when i watched the cgp grey video on them, but now that you mention it, i definitely agree

          • eksb@programming.dev
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            4 months ago

            This is expensive to address because you have to separate cyclists out to the right before the right car lane splits for right turns before the crossover. And then you have to build a bridge or tunnel for cyclists and pedestrians. On each side.

            Really, any road busy enough to justify a diverging diamond probably already needed separated bike lanes. But in America (motto: “If you aren’t in a car, you don’t matter”), there almost certainly was not any cycling infrastructure there before.

            There is one of these near me. Their solution for pedestrians is to make them cross the high speed outer lanes four times (where drivers are encouraged to not slow down). Their solution for cyclists is take the lane and pray or get off and do what the pedestrians have to do.

            Edited for clarity: pedestrians cross four times, not drivers are encouraged to not slow down four times.

              • eksb@programming.dev
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                4 months ago

                To be clear, it is four times that pedestrians have to cross, not four times that drivers are encouraged to not slow down. Drivers are not explicitly encouraged to not slow down, but the point of the diverging diamond is to make drivers not have to slow down.

      • Jojo, Lady of the West@lemmy.blahaj.zone
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        4 months ago

        Significantly safer to navigate in practice than traditional intersections, and very straightforward to navigate, if not quite as easy as a normal intersection you’ve seen all your life.

        • waz@feddit.uk
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          4 months ago

          Never heard of or seen that, but it makes me think of the ‘magic roundabout’ concept

  • UnderpantsWeevil@lemmy.world
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    4 months ago

    One of the cooler parts of Three Body Problem was when they attempted the Orion Project to accelerate a probe to 1% of light speed.