5 ms·

There are no particles, there are only fields (2013) [pdf]

82 points by antognini 4y ago

deleted 4y ago
[deleted]
abdullahkhalids 4y ago
My version of this is as follows. Every theory starts with a collection of objects that it postulates exist in the world or system being studied. According to a child's theory of the world, ghosts exist and could be lurking in the dark. In an adult's theory of the world, ghosts don't exist. In basic classical physics the world is made up of the following objects: 1. Point particles i.e. every mass must be modeled as a particle located at exactly one point in space at every instant of time, and having no dimensions. 2. Waves, like sound waves and water waves. These were masses that moved with some symmetry and carried energy from one place to another. More advanced classical physics is able to postulate that the world also includes masses that are not point particles, but spread out over space. Moreover, it postulated that these particles and waves moved due to the influence of 3. Electromagntic and gravitational fields. This is why, when quantum phenomena was encountered, people tried to put mass objects into these buckets 1 and 2 of particles and waves Except when quantum theory was developed in 1920s/1930s, it postulated that the world was made up of only one type of "mass" object. * Quantum fields, which are somewhat similar to water waves, but actually fundamentally very different types of mathematical objects. The change in these fields continues to be driven by electromagnetism. That's all there is to it. There is no notion of "particles" within quantum theory. But somehow my fellow physicists have continued to be confused for a century and keep harking on about this concept of wave/particle duality, which has little explanatory value and even less predictive value.
- ravi-delia 4y ago
  Obviously you're correct, but you have to admit that the universe pulled a funny one here. "Particles" aren't the emergent property of quantum fields the way you'd hope. Unlike other classical phenomena, where you can sum up all the wave behavior and see where the classical illusion comes from, fields just kinda describe amplitudes over possible particle positions. We shift from configuration to configuration precisely as governed by the fields, but its over a configuration space of particles! What the hell!? Who wouldn't be confused? I honestly won't be happy until QFT has a good explanation as to why it feels the need to pretend perfect inviolable particles exist (the universe, of course, is under no obligation to oblige, but I am under no obligation to die happy).
  - namaria 4y ago
    Y'all squinting too hard looking into formulas. The artifacts we use to calculate results of experiments are not the fabric of the cosmos.
    - abdullahkhalids 4y ago
      I am sure GP is aware of the difference between reality and the map of reality. But creating maps are shown to not correspond to reality and others that do a pretty good job for parts of reality do say something about what the fabric of the cosmos could and could not be. The most striking example of this is Bell's experiments which wipe out entire classes of fabrics.
      - namaria 4y ago
        Sure, understanding the logic behind validating reality models is very useful. Surely, you also can see that pretending like valid reality models are more then useful, but a representation of the very nature of existence, is just a flight of fancy. We don't know what is reality, why is reality, and the bulk of it lies eternally beyond us, towards past and future. Sure we can figure out reality, it's all about tunnels baby! Says the ant.
      - zmgsabst 4y ago
        Sure — but equally so is the response to Bell’s inequality that we must live in a non-deterministic world… even though that’s a purely extraneous assumption (ie, we’re non-local either way). Yet, for longer than I’ve been alive physicists have blathered about this “quantum truth” that’s purely an artifact of extraneous assumptions, so far as anyone can show me.
        akimball 4y ago
        Is it extraneous to interpret schrödinger psi as a probability amplitude? If not, then all fundamental interactions are stochastic.
        4y ago
akomtu 4y ago
Or maybe there are no fields, only particles, but the observer sees particles by convolving them with a wave, so everything appears as waves.
- antonvs 4y ago
  Wake me up when you can reconcile that picture with relativity.
namaria 4y ago
Why are humans so obsessed with projecting our mental abstractions we use to engineer and reason about physical reality into a be all end all theory of existence? Quite pretentious for some monkeys who just learned how to fly 4 generations ago.
- primeblue 4y ago
- pizza 4y ago
  Why should we not consider the emergence of human scientific abstractions itself any less a part of physical reality unfolding? If anything, while I agree with you we are but animals in the grand scheme of things, the fact that we have significantly altered our material daily existence so significantly and so rapidly should further convince you that the mental abstractions we use to describe the world nowadays are unusually well-grounded in reality, compared to the past. In certain places, anyway.
  - namaria 4y ago
    So civilization's success means some people sometimes are right about their ideas of reality. Still weird to me that a lifeform in a random little planet in a random little galaxy claims to have the essence of universal reality figured out. Pointing to our scribbles and how logically concatenated they are just adds comic value in the picture I'm seeing.
    - k__ 4y ago
      If reality behaves the same everywhere, it doesn't matter how random we are placed in the universe.
    - pizza 4y ago
      It gets even funnier - it would appear that the universe is itself struggling at understanding itself; people just appear to be a byproduct of this process ¯\_(ツ)_/¯
    - 4y ago
Gnarl 4y ago
Much recommended science blog on the emerging topic of "its all light": https://drgblackwell.substack.com/ https://drgblackwell.substack.com/
- ergonaught 4y ago
  Is there a reason to believe that this is not the work of a (presumably) educated and intelligent person who has fundamentally misunderstood the subject?
JediLuke 4y ago
deleted 4y ago
[deleted]

82 points by antognini 4y ago

deleted 4y ago

[deleted]

My version of this is as follows. Every theory starts with a collection of objects that it postulates exist in the world or system being studied. According to a child's theory of the world, ghosts exist and could be lurking in the dark. In an adult's theory of the world, ghosts don't exist. In basic classical physics the world is made up of the following objects: 1. Point particles i.e. every mass must be modeled as a particle located at exactly one point in space at every instant of time, and having no dimensions. 2. Waves, like sound waves and water waves. These were masses that moved with some symmetry and carried energy from one place to another. More advanced classical physics is able to postulate that the world also includes masses that are not point particles, but spread out over space. Moreover, it postulated that these particles and waves moved due to the influence of 3. Electromagntic and gravitational fields. This is why, when quantum phenomena was encountered, people tried to put mass objects into these buckets 1 and 2 of particles and waves Except when quantum theory was developed in 1920s/1930s, it postulated that the world was made up of only one type of "mass" object. * Quantum fields, which are somewhat similar to water waves, but actually fundamentally very different types of mathematical objects. The change in these fields continues to be driven by electromagnetism. That's all there is to it. There is no notion of "particles" within quantum theory. But somehow my fellow physicists have continued to be confused for a century and keep harking on about this concept of wave/particle duality, which has little explanatory value and even less predictive value.

ravi-delia 4y ago
Obviously you're correct, but you have to admit that the universe pulled a funny one here. "Particles" aren't the emergent property of quantum fields the way you'd hope. Unlike other classical phenomena, where you can sum up all the wave behavior and see where the classical illusion comes from, fields just kinda describe amplitudes over possible particle positions. We shift from configuration to configuration precisely as governed by the fields, but its over a configuration space of particles! What the hell!? Who wouldn't be confused? I honestly won't be happy until QFT has a good explanation as to why it feels the need to pretend perfect inviolable particles exist (the universe, of course, is under no obligation to oblige, but I am under no obligation to die happy).
- namaria 4y ago
  Y'all squinting too hard looking into formulas. The artifacts we use to calculate results of experiments are not the fabric of the cosmos.
  - abdullahkhalids 4y ago
    I am sure GP is aware of the difference between reality and the map of reality. But creating maps are shown to not correspond to reality and others that do a pretty good job for parts of reality do say something about what the fabric of the cosmos could and could not be. The most striking example of this is Bell's experiments which wipe out entire classes of fabrics.
    - namaria 4y ago
      Sure, understanding the logic behind validating reality models is very useful. Surely, you also can see that pretending like valid reality models are more then useful, but a representation of the very nature of existence, is just a flight of fancy. We don't know what is reality, why is reality, and the bulk of it lies eternally beyond us, towards past and future. Sure we can figure out reality, it's all about tunnels baby! Says the ant.
    - zmgsabst 4y ago
      Sure — but equally so is the response to Bell’s inequality that we must live in a non-deterministic world… even though that’s a purely extraneous assumption (ie, we’re non-local either way). Yet, for longer than I’ve been alive physicists have blathered about this “quantum truth” that’s purely an artifact of extraneous assumptions, so far as anyone can show me.
      - akimball 4y ago
        Is it extraneous to interpret schrödinger psi as a probability amplitude? If not, then all fundamental interactions are stochastic.
      - 4y ago

akomtu 4y ago

Or maybe there are no fields, only particles, but the observer sees particles by convolving them with a wave, so everything appears as waves.

antonvs 4y ago
Wake me up when you can reconcile that picture with relativity.

namaria 4y ago

Why are humans so obsessed with projecting our mental abstractions we use to engineer and reason about physical reality into a be all end all theory of existence? Quite pretentious for some monkeys who just learned how to fly 4 generations ago.

primeblue 4y ago
pizza 4y ago
Why should we not consider the emergence of human scientific abstractions itself any less a part of physical reality unfolding? If anything, while I agree with you we are but animals in the grand scheme of things, the fact that we have significantly altered our material daily existence so significantly and so rapidly should further convince you that the mental abstractions we use to describe the world nowadays are unusually well-grounded in reality, compared to the past. In certain places, anyway.
- namaria 4y ago
  So civilization's success means some people sometimes are right about their ideas of reality. Still weird to me that a lifeform in a random little planet in a random little galaxy claims to have the essence of universal reality figured out. Pointing to our scribbles and how logically concatenated they are just adds comic value in the picture I'm seeing.
  - k__ 4y ago
    If reality behaves the same everywhere, it doesn't matter how random we are placed in the universe.
  - pizza 4y ago
    It gets even funnier - it would appear that the universe is itself struggling at understanding itself; people just appear to be a byproduct of this process ¯\_(ツ)_/¯
  - 4y ago

Gnarl 4y ago

Much recommended science blog on the emerging topic of "its all light": https://drgblackwell.substack.com/ https://drgblackwell.substack.com/

ergonaught 4y ago
Is there a reason to believe that this is not the work of a (presumably) educated and intelligent person who has fundamentally misunderstood the subject?

JediLuke 4y ago

deleted 4y ago

[deleted]