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> mostly just empty space I'm so tired of this. If atoms are "empty space", then there's no such thing as non-empty space, which makes the concept meaningless.

> mostly just empty space I'm so tired of this. If atoms are "empty space", then there's no such thing as non-empty space, which makes the concept meaningless. Electron clouds have all the properties we want from non-empty space, mainly excluding other objects made of non-empty space, so let's just admit that's what non-empty space is and move past this pseudo-profound silliness.

thereisnospork 2y ago
Ye olde Rutherford experiment nicely illustrates the points of 'yes it is all empty space' and why that is both non-obvious and profound. Nothing pseudo about it.
- andrewflnr 2y ago
  That's a defensible perspective, I guess, but the fact remains that you don't fall through your chair, and that's all we really want from a description of "solid" matter. Turns out your chair behaves weirdly when you shoot alpha particles through it, but your bottom isn't made of alpha particles, so what does that prove as far as solidity goes? I suppose it proves that solidity is a non-fundamental property of matter, and that is profound, but that doesn't mean we need to change the name. It just seems like a semantic cul-de-sac to me.
  - BobbyTables2 2y ago
    I think of it more like a pincushion. A needle will go right into it with very little resistance. One’s hand or fingertip — not so much.
    - andrewflnr 2y ago
      Right. And no one confuses a pincushion for empty space. They just also don't confuse it with adamantium.
      - vlovich123 2y ago
        You can sit on a pincushion filled very densely with needles equally well as a solid wooden chair. Yet the needles clearly have more space between them than a solid block of wood. Your personal inability to penetrate or see into that space doesn’t mean the space isn’t there. Indeed, how do you know if there’s a microscopic crack? You look at photons reflecting and amplify them into your optical range. How do we know whether or not there’s space in the atom range? We use an electron microscope. It’s still a microscope - a tool to objectively pierce the physical realm in ways that you can’t with your own sense.
        andrewflnr 2y ago
        None of that, even to the extent it's true, makes a lick of difference to my point. You definitely don't need to lecture me about how scientific instruments supply info my biological senses can't. I know how subatomic particles work. I'm trying to make a point about obfuscatory terminology.
- MalbertKerman 2y ago
  > Ye olde Rutherford experiment nicely illustrates the points of 'yes it is all empty space' No, it does not. It illustrates that the portion of an atom that strongly scatters alpha particles occupies a small fraction of the atom's volume. Asserting that alpha particle scattering is the only correct definition of the threshold between emptiness and non-emptiness is an awfully strange position to take. When interacting with other electrons at energy scales relevant to human life, i.e. maybe ten electron volts and down, an electron cloud is somewhere between solid (core electrons especially in heavy atoms) and squishy (valence electrons). Give a rock the ol' "I refute it thus!" and your toes will report that that rock's electrons are quite competently occupying their space. Ask an alpha particle at nuclear energy scales a million times greater, and that electron cloud is like a swarm of gnats to a speeding car. The electrons only interact with the alpha electromagnetically, and it takes another object that interacts through the strong nuclear force to really bother a nucleus (most of the time). Ask a neutrino, and it will tell you that all the nuclei in the Sun are but a wisp of fog. This is a good example of how approximations valid in one regime fail in another but are not therefore useless. Rutherford's experiment reveals that there is more going on with matter than what can be probed by fingers and microscopes and chemical reactions, but it in no way invalidates those other observations.
TeMPOraL 2y ago
I don't know how established this is, but I'm partial to the "vacuum is elastic, non-linear medium, and particles are waves trapped in the non-linearity - self-confining energy" hypothesis. IANAPhysicist, but this really seems to make a lot of sense and is quite elegant: https://www.youtube.com/watch?v=tMP5Pbx8I4s https://www.youtube.com/watch?v=tMP5Pbx8I4s And with this, there's no empty space in atoms, as the vacuum perturbations from each particle spread out to infinity, so inside the atom there's more energy in those perturbations than outside - the space is less empty inside than outside.
- hoseja 2y ago
  But what is the nature of the "perturbations"? Relativistically self-interacting knots/manifolds? Can you take the elastic medium and fold it onto itself (through higher dimensions?) in a manner similar to (but not the same as) a microscopic black hole to stabilize it into a particle? Either I'm going schizo or I should read some real books on the subject.
  - TeMPOraL 2y ago
    Apparently they're just the same stuff that light is - i.e. presumably this: https://en.wikipedia.org/wiki/Vacuum#Quantum_mechanics https://en.wikipedia.org/wiki/Vacuum#Quantum_mechanics As I understand it, the idea in the video is that if vacuum can be seen as non-linear elastic medium, then with the right functions for elasticity and stress, you can create conditions where EM waves at high enough frequency will hit the "sweet spot", a local minimum, where the energy gets confined in space by those non-linear properties, and can't leave without supplying additional energy. And such confined energy seems to behave like you'd expect particles to. Again, I am not a physicist, so I'm probably wrong in understanding what half of the words I used above mean. But I do understand the idea of multiple forces creating semi-stable states that are "energy traps". For instance, the balance between electric repulsion vs. attraction from strong nuclear force is what defines how tightly bound is the nucleus of any given atom (aka. the "nuclear binding energy"). The nucleus can't expand or split apart, nor can it contract, unless you supply additional energy. When you do - say, you hit a large atom with high-speed neutrons to break past strong force attraction, or smash two small nuclei together at high speeds to overcome electric repulsion, the other force takes over resulting in a rather spectacular release of energy[0] as matter finds new stable configuration. So I feel the idea here is similar, but with stress and elasticity in place of strong and electric forces - if there's enough energy propagating through some space, the wave gets trapped in a spatially-confined region instead of dispersing into the medium. -- [0] - https://www.marketbusinessnews.com/wp-content/uploads/2014/02/Nuclear-binding-energy-curve.png https://www.marketbusinessnews.com/wp-content/uploads/2014/0...
Galatians4_16 2y ago
Ever heard of the Casimir Effect?

thereisnospork 2y ago

Ye olde Rutherford experiment nicely illustrates the points of 'yes it is all empty space' and why that is both non-obvious and profound. Nothing pseudo about it.

andrewflnr 2y ago
That's a defensible perspective, I guess, but the fact remains that you don't fall through your chair, and that's all we really want from a description of "solid" matter. Turns out your chair behaves weirdly when you shoot alpha particles through it, but your bottom isn't made of alpha particles, so what does that prove as far as solidity goes? I suppose it proves that solidity is a non-fundamental property of matter, and that is profound, but that doesn't mean we need to change the name. It just seems like a semantic cul-de-sac to me.
- BobbyTables2 2y ago
  I think of it more like a pincushion. A needle will go right into it with very little resistance. One’s hand or fingertip — not so much.
  - andrewflnr 2y ago
    Right. And no one confuses a pincushion for empty space. They just also don't confuse it with adamantium.
    - vlovich123 2y ago
      You can sit on a pincushion filled very densely with needles equally well as a solid wooden chair. Yet the needles clearly have more space between them than a solid block of wood. Your personal inability to penetrate or see into that space doesn’t mean the space isn’t there. Indeed, how do you know if there’s a microscopic crack? You look at photons reflecting and amplify them into your optical range. How do we know whether or not there’s space in the atom range? We use an electron microscope. It’s still a microscope - a tool to objectively pierce the physical realm in ways that you can’t with your own sense.
      - andrewflnr 2y ago
        None of that, even to the extent it's true, makes a lick of difference to my point. You definitely don't need to lecture me about how scientific instruments supply info my biological senses can't. I know how subatomic particles work. I'm trying to make a point about obfuscatory terminology.
MalbertKerman 2y ago
> Ye olde Rutherford experiment nicely illustrates the points of 'yes it is all empty space' No, it does not. It illustrates that the portion of an atom that strongly scatters alpha particles occupies a small fraction of the atom's volume. Asserting that alpha particle scattering is the only correct definition of the threshold between emptiness and non-emptiness is an awfully strange position to take. When interacting with other electrons at energy scales relevant to human life, i.e. maybe ten electron volts and down, an electron cloud is somewhere between solid (core electrons especially in heavy atoms) and squishy (valence electrons). Give a rock the ol' "I refute it thus!" and your toes will report that that rock's electrons are quite competently occupying their space. Ask an alpha particle at nuclear energy scales a million times greater, and that electron cloud is like a swarm of gnats to a speeding car. The electrons only interact with the alpha electromagnetically, and it takes another object that interacts through the strong nuclear force to really bother a nucleus (most of the time). Ask a neutrino, and it will tell you that all the nuclei in the Sun are but a wisp of fog. This is a good example of how approximations valid in one regime fail in another but are not therefore useless. Rutherford's experiment reveals that there is more going on with matter than what can be probed by fingers and microscopes and chemical reactions, but it in no way invalidates those other observations.

TeMPOraL 2y ago

I don't know how established this is, but I'm partial to the "vacuum is elastic, non-linear medium, and particles are waves trapped in the non-linearity - self-confining energy" hypothesis. IANAPhysicist, but this really seems to make a lot of sense and is quite elegant: https://www.youtube.com/watch?v=tMP5Pbx8I4s https://www.youtube.com/watch?v=tMP5Pbx8I4s And with this, there's no empty space in atoms, as the vacuum perturbations from each particle spread out to infinity, so inside the atom there's more energy in those perturbations than outside - the space is less empty inside than outside.

hoseja 2y ago
But what is the nature of the "perturbations"? Relativistically self-interacting knots/manifolds? Can you take the elastic medium and fold it onto itself (through higher dimensions?) in a manner similar to (but not the same as) a microscopic black hole to stabilize it into a particle? Either I'm going schizo or I should read some real books on the subject.
- TeMPOraL 2y ago
  Apparently they're just the same stuff that light is - i.e. presumably this: https://en.wikipedia.org/wiki/Vacuum#Quantum_mechanics https://en.wikipedia.org/wiki/Vacuum#Quantum_mechanics As I understand it, the idea in the video is that if vacuum can be seen as non-linear elastic medium, then with the right functions for elasticity and stress, you can create conditions where EM waves at high enough frequency will hit the "sweet spot", a local minimum, where the energy gets confined in space by those non-linear properties, and can't leave without supplying additional energy. And such confined energy seems to behave like you'd expect particles to. Again, I am not a physicist, so I'm probably wrong in understanding what half of the words I used above mean. But I do understand the idea of multiple forces creating semi-stable states that are "energy traps". For instance, the balance between electric repulsion vs. attraction from strong nuclear force is what defines how tightly bound is the nucleus of any given atom (aka. the "nuclear binding energy"). The nucleus can't expand or split apart, nor can it contract, unless you supply additional energy. When you do - say, you hit a large atom with high-speed neutrons to break past strong force attraction, or smash two small nuclei together at high speeds to overcome electric repulsion, the other force takes over resulting in a rather spectacular release of energy[0] as matter finds new stable configuration. So I feel the idea here is similar, but with stress and elasticity in place of strong and electric forces - if there's enough energy propagating through some space, the wave gets trapped in a spatially-confined region instead of dispersing into the medium. -- [0] - https://www.marketbusinessnews.com/wp-content/uploads/2014/02/Nuclear-binding-energy-curve.png https://www.marketbusinessnews.com/wp-content/uploads/2014/0...

Galatians4_16 2y ago

Ever heard of the Casimir Effect?