Is spacetime a field?

Discussion in 'General Philosophy' started by el es, Mar 5, 2019.

  1. el es Registered Senior Member

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  3. el es Registered Senior Member

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    GR can be seen as asserting the gravitational field and the geometry (of spacetime) to be indistinguishable.
     
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  5. el es Registered Senior Member

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    Does spacetime exist a priori?

    Does Loop Quantum Gravity consider gravity and spacetime to be one and the same thing?

    What approach does string theory take?
     
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  7. el es Registered Senior Member

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    Is spacetime a field?

    In the book Forces and Fields, Mary B. Hesse says yes.
     
  8. el es Registered Senior Member

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    Physicists tend to hide things behind walls of math. I want to see behind the wall.
     
  9. Michael 345 New year. PRESENT is 69 years old Valued Senior Member

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    Illegal aliens

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  10. Write4U Valued Senior Member

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    I always liked this concept, because it is so simply elegant and meets all required properties.

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    You may like this; https://arxiv.org/pdf/gr-qc/9605010.pdf (page 22)
     
    Last edited: Mar 12, 2019
  11. James R Just this guy, you know? Staff Member

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    What do fields have to do with the philosophy of science?

    It sounds more like you're asking a question about science (or maths).
     
  12. RainbowSingularity Valued Senior Member

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    i postured this question some months back, but it got ignored by some while others seemed to not really comprehend it.

    the responses and further reading suggest space-time is simply a metaphor of an unknown value.
    stephen hawking made some comments about it.

    i think the jury are still out on this one some 10 years after the term first started getting used.
     
  13. Write4U Valued Senior Member

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    This may shed some light on the nature and functions of fields. Apparently there are 4 force fields and 12 matter fields.
    plus the Higgs field.
     
    Last edited: Mar 16, 2019
  14. RainbowSingularity Valued Senior Member

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    weak fields
    strong fields
    temporary fields ?

    note time mark 18:40 ?
    the quantum grocery store sells energy in packets & lumps

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    David seems to have his own field of energy to produce lectures
    Lecture field generator.{fantastic energy}
    if you have not had your coffee your probably not paying attention lol

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    he reminds me of 2 high school class mates
    they got A's for everything without really trying(next level intellect)
     
    Last edited: Mar 16, 2019
  15. Write4U Valued Senior Member

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    Temporary fields? Do you mean dynamic fields? Or fields that emerge and disappear?

    p.s. a musing; in a quantum field is half the field in an "on" state and half the field in an "off" state?
     
  16. RainbowSingularity Valued Senior Member

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    fields that may not continually obey the known laws of fields, and that may not be readily conceived as fields because they are not continually existing in some type of semi continuous basis
    that may or may not exist along the lines of Schrodinger & Heisenberg having a love child etc.

    not essentially a new law of physics, but a field that may correlate to known individual factors but is transient in nature so it is not easily observed and more soo theoretical in nature.
    e.g dark matter interacting in a field that only becomes measurable once dark matter is able to be observed.

    that may potentially also by dynamic from a basic known perspective.

    im not really up on it so im being fairly lose,
    Schrodinger for example
    the electron having a different value by its nature of interaction(im not saying its not an electron)
    in the way they connect to form a field.

    e.g speaking in shapes....
    like a cube that is sitting stacked amongst other cubes with the outside of those lump of cubes cut to form an orb.

    the cube its self is still a cube by its self, but when put together with the other cubes it exhibits the properties of an orb as a field.
    while maintaining its properties as a cube...
    (obviously there are a few issues around if the outer cubes remain cubes when they are cut to form an orb structure but im trying to ignore that part for the explanation)
     
  17. Write4U Valued Senior Member

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    Pattern forming.

    Such as forming a curve or even a parabola as a secondary result of drawing a set of purely straight lines. The expressed language of mathematics.

     
    Last edited: Mar 17, 2019
  18. exchemist Valued Senior Member

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    We do actually have a discussion running on that, here: http://www.sciforums.com/threads/the-absence-of-power-of-gravity-at-fundamental-level.161579/page-3

    What Quarkhead is maintaining, if I understand correctly, is that spacetime is not a field but that the metric tensor, which describes the curvature of spacetime at each point in it, is a description of a field.

    But indeed this is physics rather than philosophy.
     
  19. Yazata Valued Senior Member

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    Unlike JamesR, I do think that your question is a philosophy of science question.

    It's a space, both mathematically and physically, I guess. If we ascribe physical quantities to each point in that space, then it would seem to qualify as a field as well, at least in the physics sense. (A field in mathematics is a very different kind of algebraic object, I think.)

    So I'm kind of inclined to say 'yes'. Physical space as imagined by physics has lots of physical quantities imposed on its pure geometry. It kind of slides away from being pure geometry towards being a kind of... stuff.

    This seems to be one of those areas there physics and mathematics kind of smear together.

    That's very much a philosophy-of-science issue. Is 'space' a physical or a mathematical object? The void of outer space certainly seems physical. But something like 'Hilbert space' or various kinds of 'state space' look a lot more conceptual and idealized.

    What about electromagnetic fields? Are they just a way of representing the forces that a test particle will encounter at different points in geometrical space? (Leaving aside the question of what exerts the force.) Or is an electromagnetic field a physical thing of some sort?

    I don't know the answers, but it does seem to get to fundamental ontology. (What does and doesn't really exist.)
     
    Last edited: Mar 17, 2019
  20. C C Consular Corps - "the backbone of diplomacy" Valued Senior Member

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    Frank Wilczek: "We can describe general relativity using either of two mathematically equivalent ideas: curved space-time or metric field. Mathematicians, mystics and specialists in general relativity tend to like the geometric view because of its elegance. Physicists trained in the more empirical tradition of high-energy physics and quantum field theory tend to prefer the field view, because it corresponds better to how we (or our computers) do concrete calculations. [...] the field view makes Einstein's theory of gravity look more like the other successful theories of fundamental physics, and so makes it easier to work toward a a fully integrated, unified description of all the laws. [...] I'm a field man. --The Lightness of Being: Mass, Ether, and the Unification of Forces (2008)

    Tristan Hubsch: ". . . while spacetime [...] is not itself a field, our only recourse to gathering information about it is through fields, so that it is, in this "physical" sense, defined in terms of fields. [...] echoing Alfred Korzybski's 'the map is not the territory'."

    Michael Esfeld and Dirk-Andre Deckert: ". . . one cannot read the ontology off from the mathematical structure of a physical theory, since one would in this case end up with two proposals for the ontology of general relativistic physics [...] based on two different formalisms for general relativistic physics." --A Minimalist Ontology of the Natural World (2017)

    Gali Weinstein: "Furthermore, spacetime does not claim existence on its own, but only as a structural quality of the field."

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  21. Write4U Valued Senior Member

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    I like that one.........a wave function which continues to roll along into infinity.

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    The Bohm Pilot Wave converting 2D space into 3D spacetime as it rolls outward in all directions.

    Possibly even CDT (causal dynamical triangulation) might be a constituent part of space which allows for the wave-function to become expressed as the Pilot Wave and converts space into spacetime for its inhabitant physical stuff.
     
    Last edited: Mar 18, 2019

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