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B How can something be "Zero Dimensional?"

  1. May 20, 2017 #1
    I am not a physicist by trade nor do I have any experience other than what I've read over the past few years. I once read a book by Stephen Hawking or Michio Kaku (or maybe Brian Green, I can't remember) in which they said something to the effect of "even if we had the technology to see down to the plank scale, we still would not be able to see atoms or particles, because they don't exist! They are zero dimensional points in space" That has perplexed me since I read it. I get the problem with using conventional microscopy, I know we've made progress with electron microscopy and other advances in the field, but for a such a renown physicist (who, I thought, don't believe in words like "never" and "cannot") to say never kind of shocked me. How can something have such a fundamental impact on life, matter, and everything else that exists in the Universe, yet not really be real? How can something be zero dimensional?

    To give some insight to the reader who will hopefully educate me, I'm familiar with most physics and quantum terminology. For the most part I understand quantum entanglement, Schrodinger's Wave function and particle-wave duality. I can grasp the collapsing of a wave functions, and the uncertainty principle and holographic principles. I've read about the standard model, the problems reconciling quantum mechanics and the theories of Relativity, as well as the promise and problems behind String Theory. I'm just now diving into Loop Quantum Gravity, so well see where Carlo Rovelli takes me in the coming days.

    I just don't do mathematics (unfortunately, not everyone was gifted with the ability - I'm in the process of learning, but Michael Faraday gives me some hope :). So, if someone would be so kind, how can something interact with every-day life; we collide them into each other, we isolate single atoms of the elements and use them to make time crystals; we bombard elements with neutrons to induce radioactivity. So, HOW, IF YOU'D BE SO KIND, CAN SOMETHING BE ZERO DIMENSIONAL! HOW CAN SOMEONE SAY WE'LL NEVER BE ABLE TO SEE THEM BECAUSE THEY'RE NOT THERE???

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    Last edited: May 20, 2017
  2. jcsd
  3. May 20, 2017 #2


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    If you can't remember who said it, how can you remember exactly what was said?

    Sounds like pop-sci clickbait.
  4. May 20, 2017 #3


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    Atoms have a finite size. We can see them. Here is a video.

    We cannot see them individually with visible light because its wavelength is too long. That's like trying to feel individual grains of sand next to each other with very sturdy gloves: It just doesn't work. So what - you just have to use better tools, like electron microscopes.

    Without a precise quote, ideally with its context, it is hard to guess what was meant (and who said it), but I'm sure none of the possible authors claimed we cannot see atoms.
  5. May 20, 2017 #4


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    This actually gets into an interesting discussion on what the size of a particle is. My understanding is that when we say that the size is zero, we mean that when we measure the location of a particle our instruments localize its location down to a region of space of any arbitrary size. No matter how tightly we measure its location, we will only ever measure a single location and not two locations simultaneously. As far as we can tell, we can measure a region of space of any size and we will either find the electron there or we will not. There is no "half detection".

    However, we still have to note that a particle's influence due to any properties such as charge extends throughout space. So even if an electron is considered to be a point-like particle, its electric field is not a point and will act accordingly.

    Note that anyone who says that a particle isn't real is simply wrong or doing a poor job of explaining what they mean. Particles are as real anything else.
  6. May 20, 2017 #5
    You're right it definitely does. I remembered it because I was flabbergasted. And it was George Musser in his book "Spooky Action at a Distance." All my books are at school, I will update the post on Monday. All the books I've read start to all melt together because they talk about different sides to the same coin, or the same side to the same coin.
  7. May 20, 2017 #6
    I'm almost certain it was George Musser's "Spooky Action at a Distance." I will quote him directly on Monday, all my books are in my classroom. I've seen the video's...

    So how about smaller particles...neutrons, protons, electrons...or even quarks? What about photons? are these "real", physical particles? or do they only pop into existence when an observation is made?
  8. May 20, 2017 #7


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    Neutrons and protons are not fundamental particles. They are composite particles made up of more fundamental particles and are not point-like (just like how an atom is not point-like). Photons are also real particles but behave a little differently in ways that I don't think I can explain very well.
  9. May 21, 2017 #8

    A. Neumaier

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    Photons pop out of existence when they are observed. But they must have existed before since nonexistent objects cannot be observed.
    This is figurative speech aimed at exaggeration for rhetoric purposes. Indeed, atoms can be seen; see Chapter A6: The structure of physical objects of my Theoretical Physics FAQ. Points in space are indeed zero-dimensional but all atoms and particles are extended 3-dimensional objects. For tiny particles, this is generally taken to mean that they have nontrivial ''form factors'') specifying their ''form'' (in a somewhat abstract way revealed by scattering experiments).

    On the other hand, virtual particles are theoretical, nonphysical, zero-dimensional constructs without form. They are just used as formal scaffolding to construct the correct physical theories through a complicated process called renormalization. However, in popular text they are taken as real, equipped with lots of magical, unphysical qualities. See my series of insight articles, starting with ''Misconceptions about Virtual Particles''.
    Last edited: May 21, 2017
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