• theneverfox@pawb.social
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      1 day ago

      Think of it like this…a photon is both a wave, and the smallest discrete unit of energy

      When the wave is absorbed by something, the energy must be transferred. But the smallest unit of energy is the full photon, and so the full amount of energy of the wave is absorbed at a single point, because there’s no such thing as partial photons

      Or in other words, the wave doesn’t turn into a particle, the energy gets spent at a single point in space

      Really, I think all of quantum physics works like this. Electrons don’t exist as a point in space, they exist in an area. They’re fields, they’re not necessarily moving fast, which is why atoms don’t randomly slip through each other and we can’t measure all the properties of it at once

    • AppleTea@lemmy.zip
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      2 days ago

      oh boy, here I go banging this drum again:

      When physicists say “observe”, they actually mean “measure”. And to measure a photon of light, you have to interact with it somehow, there is no passive way to do so.

      The post’s header image implies that the interference pattern goes away just by looking at it. If that were the case, we would never see the interference pattern, never know it was there in the first place! In the actual experiment, they put a sensor at one or both of the slits. But to “sense” a single photon, you have to interact with it in some way. Otherwise you wouldn’t know it was there.

      Again, this is where the language trips us up. Rather than “sensor”, would really be more accurate to say they put a photon-touch-er at the slits.

      So, what we actually get is “Touching the photon changes the photon’s behavior.” The universe doesn’t magically infer when we happen to be looking at it, there is no spooky action-at-a-distance!

      • bilouba@jlai.lu
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        1 day ago

        Sorry but you are wrong. This is how I understood it too, but this is way weirder. Look into quantum eraser or polarization experiment. Information cause the wave collapse. You can use another set of polarization at 45° to activate the interference pattern again. It goes beyond physical perturbation and it has been demonstrated by experiment. I’m not a scientist and this is fairly new information to me so I can’t explain it to you very clearly I’m sorry, but trust the science, things get weird at the quantum scale. Intuition doesn’t work at this level.

        • VoterFrog@lemmy.world
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          19 hours ago

          I don’t think it’s wrong, just simplified. You don’t really have to touch the photon, just affect the wave function, the statistical description of the photon’s movement through space and time. Detectors and polarizers, anything that can be used to tell exactly which path the photon took through the slits will do this. Quantum eraser experiments just show that you can “undo the damage” to the wave function, so to speak. You can get the wave function back into an unaltered state but by doing so you lose the which-way information.

          • bilouba@jlai.lu
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            12 hours ago

            It really is about information and coherence and is really hard to explain and I’m not qualified to do it. For me the polarization show that it is beyond touching anything. You can use the first pass of filter to aquire information and it break the interference. But then you can use a second pass to remove this information and get an interference back. The photon was “touched” by both filter, so how come interference get back ? A photon is not the same as light (many photons) so you can’t really apply electromagnetic reasoning to the quantum world. Sorry to do an appeals to authority, but it’s been literally 100 years since the discovery of this science and if it was simply like space time and electromagnetic waves it wouldn’t be know as this really weird and unintuitive model that works on really small scale. You can create a pair of photon and observe their linked property even kilometers apart when they collapse. It weird, but having information about the system, change it. Of course it’s not literally like this meme. But again, I’m not an expert or a scientist, so if you know more, please correct me.

      • 474D@lemmy.world
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        1 day ago

        But then what is the significance of this experiment? Why is it so popular if it’s that simple and why is it usually associated with quantum physics?

        • Farid@startrek.website
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          1 day ago

          If not touched the photon goes through both slits and interacts with itself, which is still super weird. Basically, it’s a wave if not touched, but a particle if touched.

          • Agent641@lemmy.world
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            1 day ago

            Photons exist at the edge of our dimension, not really a part of it, but skimming the borderlands between dimensions. Like a bug on the surface of a lake, it influences the lake and the atmosphere simultaneously, can be inferred by its effect on the lake, but it cannot be observed (eaten) by a fish without also fully entering the lake dimension. In this borderland state the photon has the theoretical potential to influence many dimensions, but doesn’t belong to any one of them. Measuring, or touching the photon turns that potential into causative certainty where the photon is now part of our dimensions’ event chain, pulling it fully into our dimension to the exclusion of all others and converting it from a probabilistic multidimensional potential into a deterministic unidimensional particle.

            I just made all that up but it sounds pretty good IMO.

          • Gremour@lemmy.world
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            1 day ago

            Which suspiciously reminds optimization. Like computer game with infinite procedural world, where map chunks only generated where player interacts with world, being just formula (algorithm) everywhere else.

            • Farid@startrek.website
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              1 day ago

              I have actually seen that video. But my simplification is still correct, except that I should’ve used the word “behaves”. Because for the purposes of how it will behave the simplification shows the effects clearly.

      • Iunnrais@lemmy.world
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        1 day ago

        I’ve asked this of a physicist friend of mine, and he insisted there wasn’t actually photon touching being involved. I honestly didn’t understand his explanation fully though. Photon touching makes sense to me. Whatever he said was much more confusing… yet he gets grant money to actually study lasers and put out research papers, and I don’t, so…

        • AppleTea@lemmy.zip
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          15 hours ago

          “Photon touching” was a somewhat glib way of putting it on my part.

          What does your friend think of this statement:

          When physicists say “observe”, they actually mean “measure”. And to measure a photon of light, you have to interact with it somehow, there is no passive way to do so.

          • Iunnrais@lemmy.world
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            14 hours ago

            No, that exact thing, interacting with the particle, is what he was saying does not happen, or at least is not required for the effect to happen. This is where his explanation lost me, because my understanding had aligned with yours, and he spent a good half hour trying to explain how I was wrong, and to be honest, it didn’t quite sink in.

            I remember there was a lot of math in his explanation, and multiple different interpretations and angles of understanding — but my takeaway was just that he strongly claimed no interaction with the particle whatsoever was required for uncertainty and the weird particle/wave dichotomy to take place, and that experimental evidence has been provided for this. Furthermore, that I have no fucking idea what observation means, but it doesn’t apparently mean interaction with the particle at all.

      • anon@lemmy.sdf.org
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        1 day ago

        So what’s surprising about the experiment?

        Of course, when you interact with things they change

        • davidgro@lemmy.world
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          1 day ago

          As another comment said, the wave behavior when not measured is hard to explain if one thinks of photons as little particles that classically would need to go through one slit or the other. It seems each one goes through both slits and self-interferes.

          And when measured, sure enough they act like little particles that need to go through one slit or the other.

    • AnarchistArtificer@slrpnk.net
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      1 day ago

      The thing that made it click for me is to realise that particles and waves don’t really exist — they’re just terms we use to try to understand the world. When we see weird quantum shit happening, it’s not actually weird in and of itself, we’re just finding that our reductionist (but often useful) models are breaking down and we can’t straightforwardly say “that’s a particle” or “that’s a wave”.

      I think of it as analogous to statistical averages. If I have a group of 100 people for whom I know the average height (and other summary statistics). Thinking of them in terms of the group is like treating them as a wave. They don’t have a precisely defined position (because they’re a diffuse blob of people), and although I know their average height, it’s clouded by uncertainty. When we do statistics on a group of people, it’s almost as if the individuals cease to exist. If all you have are the summary statistics from the group, you can’t know the heights of any individuals within the crowd.

      I can “zoom in” and pluck a person from the crowd and measure their height, then that’s sort of like wave function collapse. Now I can precisely define the position of this person, because they’re just one person — if someone says “which person are you talking about?”, I can point to them and say “this one here”. However, I don’t know anything about their surrounding context — whether they’re taller or shorter than average. They’re basically a particle.

      The key to this is how “zooming in” on an individual person gives us a fundamentally different perspective to the zoomed out view of the crowd.

      • bstix@feddit.dk
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        9 hours ago

        I have come to the conclusion that everything, from the largest galaxy clusters to the tiniest quark and all the laws of physics, is nothing more than a fractal caused by rotation in the initial moment of creation of our local instance of existence that we call the universe. There are no particles, no waves. Only rotation.

      • potoooooooo ✅️@lemmy.world
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        13 hours ago

        Maybe the whole wave function/pattern deal is like how British people are just naturally good at forming lines, even if there isn’t a sign indicating to do so.

        • AnarchistArtificer@slrpnk.net
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          12 hours ago

          I do enjoy being part of a nice, orderly queue. Makes me feel like I have some purpose in life. I can just slip partway into derealization as I submit my will to the queue.

          I didn’t notice it as a thing that we did until I went travelling in Europe and frequently found myself ambiently stressed due to the lack of queue in a situation that would benefit from one. Sometimes if enough British people congealed together in one place by coincidence, we might find ourselves forming a neat little queue.

          There’s so much that makes me ashamed to be British, but this is silly and fun; I like it.

    • ඞmir@lemmy.ml
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      1 day ago

      I don’t think anyone figured out the “why” for wave-function collapse yet, the Copenhagen interpretation is obviously flawed. PBS had a good video about it a few months ago, but if you don’t get it, that’s not weird since the leading theories for WFC are all inelegant.

        • ඞmir@lemmy.ml
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          11 hours ago

          Uhh it still doesn’t explain why we only perceive a randomly chosen one in those many worlds, does it? Like where is the die roll coming from?

          • humorlessrepost@lemmy.world
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            2 hours ago

            Each result happens, with a “you” perceiving each, because you’re entangled with the system in question.

              • humorlessrepost@lemmy.world
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                1 hour ago

                There’s nothing special about this one. The others could ask the same question.

                There’s nothing unique about humans that make them separate from the systems they entangle with when they observe them. You’re just a quantum system like the electrons in the experiment.