For me it is the fact that our blood contains iron. I earlier used to believe the word stood for some ‘organic element’ since I couldn’t accept we had metal flowing through our supposed carbon-based bodies, till I realized that is where the taste and smell of blood comes from.

    • I mentioned this one to my friends the other day and it took so much convincing before they actually believed me! Definitely an interesting one. Venus also spins the opposite direction to all the other planets in the solar system, meaning the sun rises in the west and sets in the east.

      • You’re close. Not the tilt of its axis, but its rotation around its axis (day) is slower than its rotation around the sun (year).

        Earth’s axis is tilted at about 23 degrees, which causes the seasons. Venus, by contrast, is tilted only about 2.6 degrees, and thus basically doesn’t have seasons in a comparable way.

        Earth’s axis does very slowly wobble around (precession). Over long enough time scales, this affects the seasons, and it means the North Star has not always been aligned with Earth’s North - once, North pointed at a patch of black sky and the North Star was just another star appearing to rotate around that arbitrary point.

        I’d imagine Venus’s axis might also wobble at least somewhat, but I haven’t actually looked into this at all.


        Thinking about this sent me down a rabbit hole because the day and year lengths are so extremely close to each other, and Venus rotates around its axis clockwise (unlike the other planets) while spinning around the sun clockwise, and its tilt is so slight… so as it spins around the sun, it rotates just enough to keep one side facing the sun almost all the time. I ended up googling whether it was tidally locked, like the moon is to Earth (such that we only ever see one side and it never changes) - and apparently it would be, but its atmosphere is so wild that it prevents tidal locking. But it almost is. It kinda has a dark side, and a light side, like the moon, but there’s just enough mismatch between the yearly rotation the axial rotation that the side facing the sun changes slowly. This is the first article I found.

        From that article, it seems like the daylight hours you’d experience standing on the surface of Venus would be 117 Earth days of light, before it got dark again. So the sun would rise, and then you’d have about half a Venus year (aka about half a Venus day, too) of daylight before you’d see night again. And then it’d be night for the rest of the year. But still scorching hot because atmosphere.

        Anyway this is blowing my mind a bit. I feel like I should have known this - I used to be obsessed with astronomy when I was little. Maybe I knew it once and forgot. I don’t know. But dayum. Planets are cool.

      • Short: It completes a full 360° of the sun before the planet itself does a full 360° spin.

        A few sentences longer:
        In planet Earth human terms, we have defined one day as “how long it takes the planet to do a full 360 degree rotation”. Example: You spin a basketball on your finger and it does one full rotation.

        A year to us is “how long it takes the planet to go around the sun”. Example: You hold a basketball out in front of you and you do one full rotation.

  • Not exactly bizarre, but it’s fun to learn that the delicious fragrance of shrimps and crabs when cooked comes from chitin, and chitin is also why sautéed mushrooms smell/taste like shrimps.

    And since fungi are mostly chitin, plants have evolved defenses against fungi by producing enzymes that destroy chitin, which is how some plants eventually evolved the ability to digest insects.

    EDIT: a previous version of this post mistakenly confused chitin with keratin (which our fingernails are made of). Thanks to sndrtj for the correction!

  • Time relativity always boggles my brain, I accept the fact but I find crazy that if I strap my twin and his atomic clock to a rocket and send them out to the stratosphere at the speed of light, when they return he’ll be younger than me and his clock will be running behind mine. Crazy

    • It’s even crazier because you don’t need to reach the speed of light. It’ll happen in a smaller degree for any speed. Even in mundane conditions.

      For example, if your twin spent four days in a 300km/h bullet train, for you it would be four days plus a second.

      Usually this difference is negligible, but for satellites (that run at rather high speeds, for a lot of time, and require precision), if you don’t take time dilation into account they misbehave.

      (For anyone wanting to mess with the maths, the formula is Δt’ = Δt / √[1 - v²/c²]. Δt = variation of time for the observer (you), Δt’ = variation of time for the moving entity (your twin), v = the moving entity’s speed, c = speed of light. Just make sure that “v” and “c” use the same units.)

        • Without Einstein, I think that the discovery of time dilation would be delayed by only a few years. There were a lot of people working in theoretical physics already back then; someone else would inevitably dig through Lorentz’ and Poincaré’s papers, connect the dots, and say “waitaminute time might be relative”. From that, time dilation is a consequence.

          In special I wouldn’t doubt that Max Planck would discover it.

          I’m saying that because, in both science and engineering, often you see almost concurrent discoveries or developments of the same thing, because the “spirit of a time” makes people look at that aspect of reality or that challenge and work with it. The discovery of helium and the development of aeroplanes are examples of that.

        • IIRC the orbit of Mercure doesn’t work with Newton Model, and astronomers were predicted the discovery of Vulcain a small planet between Mercure and the Sun. So a new model had to be invented since Vulcain couldn’t be found.

      • Yes I knew about that and I’m glad that doesn’t make it crazier for me, instead it makes it easier to accept. If it were something that happened only after hitting some arbitrary speed value I’d be a lot more mentally damaged

    • The part that I understand in the intellectual sense, because I know or at least used to know how it follows from the math, but which just doesn’t feel like it should be the case, is the whole “relativity of simultaneity” aspect of it. That there isn’t an objectively true order in which events happen in, if the events in question aren’t linked by cause and effect. That is to say, it is possible for one person to see an event A happen before another event B, a second person to see the two happen at exactly the same time, and a third to see event B happen first and then event A, and for all three of them to be equally right. It just feels like, on some level, there ought to be one objectively true order to time, a single valid timeline that all events can be placed in relative to eachother, and for time not to work that way feels so absurd as to not even be able to articulate why the idea feels wrong.

    • From what I understand, you are always travelling at the speed of light through space/time, but when you move at high speeds through space that shifts the proportion of your speed out of the time dimension. And a photon travels only through space, experiencing no time between the time it was emitted and the time it was absorbed. What I just can’t wrap my head around is the concept of travelling at some speed without involving the time dimension at all.

  • That “I” am pretty much just the construct of electrons flying around my brain.

    That you need to lay down K.O. for many hours every day, otherwise you get insane.

    That we are always only 2min or so away from death, if we stopped breathing.

    That everything I eat actually gets digested into mousse and bacteria are in my body, digest it and I get the elements into my blood.

    That our world is so big, but you could also walk to China Japan from the EU, if you had enough time. But also its crazy how huge our common trade routes are.

    That a weird minicomputer in my pocket can store 128GB of information, access a wireless network from across the whole planet, and can remember so much more than my brain

  • Let’s stick with the iron in your hemoglobin for some more weirdness. The body knows iron is hard to uptake, so when you bleed a lot under your skin and get a bruise, the body re-uptakes everything it can. Those color changes as the bruise goes away is part of the synthesis of compounds to get the good stuff back into the body, and send the rest away as waste.

    In the other direction, coronaviruses can denature the iron from your hemoglobin. So some covid patients end up with terrible oxygen levels because the virus is dumping iron product in the blood, no longer able to take in oxygen. I am a paramedic and didn’t believe this second one either, but on researching it explained to me why these patients were having so much trouble breathing on low concentration oxygen… the oxygen was there, but the transport system had lost the ability to carry it.

  •  Urist   ( @Urist@lemmy.ml ) 
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    411 year ago

    There is about 8.1 billion people in the world. Assuming romantic cliches to be true and that we all have exactly one soulmate out there, we would have a very hard time sifting them out. If you were to use exactly one second at meeting a person it would take you 257 years to meet everyone alive on earth at this moment, which due to human life span being significantly shorter and the influx of new people makes the task essentially impossible without a spoonful of luck. Moral of the story: If you believe you have found your soul mate, be extra kind to them today.

    • Soul mates are made, not found. You get with someone compatible to you, and through the sharing of experiences and affection, if nothing goes excessively wrong, they become unique for you.

    • If you were to use exactly one second at meeting a person it would take you 257 years to meet everyone alive on earth at this moment

      Well I don’t need to meet everybody. There’s no need to meet anyone who doesn’t match my sexual preferences, so that’s half right there. Then we can also cut everyone who’s sexual preferences I don’t meet, as well as anyone outside of a given age range (most of the people on earth are much younger than me and would be inappropriate for me to date). We can probably get that down to about 50-60 years. (At one second per person).

      •  Urist   ( @Urist@lemmy.ml ) 
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        21 year ago

        The thought experiment was just an attempt to show how hard it is to wrap our minds around big numbers. Even a tangible number such as the amount of people in the world.

    • I used to be like this, but with movies. When I first met my wife, she was utterly baffled at the concept of somebody not enjoying movies, and she made it her mission to make me enjoy them.

      Come to think of it, she actually doesn’t like music much. I’ve failed to change her opinion on that though because my taste in music is shit (and I’m proud of it.)

  • The USA has 157 million workers, shuffling 140,000 years of work a day. One in 4 has an idea. One in five of those is a good idea. Two thousand stakeholders can make it an innovative idea. So, they can pump 3.5 years of brute force innovation into the world every single day. That’s well over a thousand years of advancement per year.

    Critical mass populations that can keep up with their own development are a serious creative force to be reckoned with. And human evolution has been exceeded by innovation, dramatically.