xkcd #3141: Mantle Model

Title text:

Mantle plumes explain Hawaii, Yellowstone, Iceland, the East African Rift, the Adirondack uplift, the Permian extinction, the decline of Rome, the DB Cooper hijacking, and the balrog in Moria. Those little hills of sand in your yard are caused by antle plumes.

Transcript:

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Source: https://xkcd.com/3141/

explainxkcd for #3141

  • panda_abyss@lemmy.ca
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    1 day ago

    This is how I feel about the double slit experiment.

    Lights not a wave and a particle depending on whether you observe it. Something else is going on, that’s bullshit.

    • Cethin@lemmy.zip
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      10 hours ago

      The problem is the word “observation.” Most people interpret that to mean a person look at it. This isn’t the case. What it means is if it interacted with something where knowledge of its position is required. If this happens then the waveform collapses and a specific position is set. Before then it doesn’t have a fixed position and the position is described as a probability distribution.

      • DragonTypeWyvern@midwest.social
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        2 hours ago

        It’s a good description, but the problem is you’ve still just outsourced the pseudo-mystical role of the observer in this explanation with that “requires knowledge” bit.

        I think a lot of the difficulty in explaining these things is ultimately semantics.

    • OboTheHobo@ttrpg.network
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      6 hours ago

      Ehh, its a bit more than that.

      Its a particle in that we know they are quantized into single photons. As in, it is impossible to observe half of a photon, or any non-integer number of photons, and one photon can only be observed in one place. This makes it like a particle.

      But its a wave in the way it behaves - it can interfere (not just with other photons, with itself), and its movement can only be described through wave functions that can even take seperate paths at the same time, according to how waves propogate.

      And, there are ways in which they act like particles no matter how they are observed, and same for wavelike behavior

      Worth noting: “observation” is just physical measurement. You have to keep in mind that observing something fundamentally requires interacting with it - in order to look at an apple, photons must bounce off of it, which is a physical interaction. On the quantum scale, these interactions cannot be ignored.

      Also also: this isn’t just photons, everything is like this. It may not align with how we observe things on a macroscopic scale, but this is fundamentally how the universe works.

      • Cocodapuf@lemmy.world
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        10 hours ago

        Also also: this isn’t just photons, everything is like this. It may not align with how we observe things on a microscopic scale, but this is fundamentally how the universe works.

        Wow, I think this answered my question before I asked it. So yeah, I was wondering about that double slit experiment, I’ve seen it demonstrated with photons and visible light, but do the principles demonstrated by the experiment actually apply to other particles? In the right environments, do atoms behave similarly?

        • OboTheHobo@ttrpg.network
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          6 hours ago

          So the thing that gets weird is that the heavier the particle is the more likely it is to interact with the slits themselves on the way through, in which case the wavefunction will collapse and it will seem to go through only one slit. Also, as the other person stated, even a hydrogen atom is really 4 fundamental particles that can interact with eachother. I’m not totally sure if double slit has been demonstrated with atoms but I do know it’s been done many times with electrons.

          Edit: its actually totally possible to do it with much, much larger things. From wikipedia:

          The experiment can be done with entities much larger than electrons and photons, although it becomes more difficult as size increases. The largest entities for which the double-slit experiment has been performed were molecules that each comprised 2000 atoms

          And here’s the study that did it: https://doi.org/10.1038%2Fs41567-019-0663-9

        • vithigar@lemmy.ca
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          10 hours ago

          In theory yes, but once you have multiple particles interacting things get really complicated really fast and nice tidy interference patterns like in the double slit experiment become much less common.

          All atoms are multiple particles at quantum scales, even a single hydrogen atom is comprised of four.

          • Cocodapuf@lemmy.world
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            9 hours ago

            All atoms are multiple particles at quantum scales, even a single hydrogen atom is comprised of four.

            And I imagine we don’t have great methods for manipulating subatomic particles… Quarks and such don’t have magnetic charges, they’re probably hard to control as well as probably unstable on their own. So as a result I’d wager it’s hard to run experiments with those.

    • lemonskate@lemmy.world
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      1 day ago

      You’re right that light is not “a wave and a particle depending on whether you observe it”. Instead, light is a quantized field. It is a field because it exists at every point and allows for wave-like behavior such as superposition and interference (both things seen in all fields, like waves in water or radio, etc.). But it is quantized because when the field interacts it does so via photons which can only exist in integer quantities. This quantization of interaction of the underlying continuous field gives us all the “weirdness” we see. Okay, not quite all of it, there are still even weirder parts of quantum mechanics, but it does explain the double slit experiment.

      • Dragon Rider (drag)@lemmy.nz
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        18 hours ago

        Still doesn’t explain how superpositions can collapse from interaction. Drag doesn’t believe it, drag thinks they stay in superposition and whatever interacted with them is also in superposition now.

    • four@lemmy.zip
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      23 hours ago

      I’m with you on that one. I don’t care what the scientists say, there’s no way quantum physics is random, we just don’t know where to look yet. And entanglement? Nah, you made this one up.

      Anyway, I didn’t get into a university, but I’m not bitter about it, no.