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This is really interesting. Perhaps there is also a chance that electromagnetic fields are indeed entirely responsible for gravity, in some complicated yet unkn

This is really interesting. Perhaps there is also a chance that electromagnetic fields are indeed entirely responsible for gravity, in some complicated yet unknown manner.

danbruc 7y ago
No, energy curves the gravitational field and there are other forms of energy than the energy of the electromagnetic field. For example, if you start walking, you gain kinetic energy and this will affect the gravitational field, not much but it will.
kgwgk 7y ago
What would that mean? As far as we know there is gravity in the absence of EM fields and EM energy produce gravitational effects just like other forms of energy (and in the realm of direct human experience the contribution of EM is negligible).
- dschuetz 7y ago
  "there is gravity in the absence of EM fields" That just cannot be true. EM fields are just about everywhere. They permeate space almost as universally as gravity, but in form of photons (to name higher energy EM fields here) or other low energy waves. Gravity accumulates with great masses, mass is also energy (in rest). The article explores the idea that pure kinetic energy in form of photons indeed might have at least gravity-like properties. My presumption is that atoms are somehow made of really high energy EM fields so that they appear to be massive. Consequently, atoms having mass or photons having inertia are responsible for gravitation, and that could mean that EM fields are the cause of gravity entirely. The problem with that presumption is that perhaps there is no way to check.
  - danbruc 7y ago
    EM fields are just about everywhere. Fields are mathematical tools, they are not - without wanting to go down the philosophical rabbit hole - real things out there in the universe. And the thing about everything just being electromagnetic fields is nonsense, physicists understand physics way better than you do. Sorry to sound condescending, but the internet already has enough obviously wrong ideas by random people without a clue what they are talking but.
    - dschuetz 7y ago
      Dude, fields are a tool physicists use to describe phenomena. It's okay to say EM fields exist because they interact with everything everywhere and we can actually observe that.
      - 100ideas 7y ago
        The universe appears to have expanded or be expanding faster than the speed of light: the diameter of the observable universe is ~42 billion light-years but best estimates of age of universe is ~14 billion years. So these fields can’t interact with everything everywhere, only the portion of the universe In the field’s lightcone. if the universe keeps this up there’s a chance some day Everything will be so stretched out that the fields will be basically redshifted to null, so not interacting with anything anywhere. That’d be lame.
        danbruc 7y ago
        [...] the diameter of the observable universe is ~42 billion light-years [...] That's the radius.
    - tsimionescu 7y ago
      Honest question: aren't radio waves "physical objects" that represent oscillations of an electro-magnetic field, to the best of our current understanding?
      - dschuetz 7y ago
        There is an agreement in physics that low energy EM fields are called waves, such as radio waves, and high energy EM fields are called photons or even particles. In any case they are actually both. If they are physical objects I don't know. I think, I wouldn't go that far.
        100ideas 7y ago
        Let’s talk virtual particles...
  - tsimionescu 7y ago
    > EM fields are just about everywhere. They permeate space almost as universally as gravity Isn't dark matter most likely some kind of material that has mass, but no EM interaction? We also know that there are interactions inside atoms (the strong and weak forces) that have no known relation to electro-magnetism, so I'm not sure what you are getting at.
    - dschuetz 7y ago
      As far as I understand, dark matter is an educated guess (which was made upon the discovery that galaxies rotate differently than expected). Something out there must be causing gravity, but we cannot see it, which means that there is no observable EM interaction. The next guess here is that dark energy has a much much higher rest energy so that no photon in this universe is able to interact with it via EM fields. The search for dark matter was unsuccessful so far, and the LHC is still trying to achieve higher energies to be able to detect dark matter. So, dark matter is just a guess. The interactions inside atoms seem to have no known relations to EM, because, and this is my guess, there are much higher energies at work than we know. So, if dark matter is hiding behind high energies so that EM interaction seems impossible, why should it be different for EM interactions inside atoms. There still is a slim chance that it might be EM, just at much higher energies.
      - danbruc 7y ago
        The interactions inside atoms seem to have no known relations to EM [...] The electromagnetic and the weak interaction are known to be different aspects of the unified electroweak interaction. There are several grand unified theories and a few hints that at even higher energies the electroweak and strong interaction also unifiy into the electronuclear interaction. Due to the high energies involved, only indirect experimental evidence seems accessable for the forseeable future but there are various groups looking for hints. I am not aware of any uncontroversial results but there are a few non-reproducable experiments, for example observations of magnetic monopoles, which might be due to experimental error but also due to the rarity of magnetic monopoles.
  - kgwgk 7y ago
    > The article explores the idea that pure kinetic energy in form of photons indeed might have at least gravity-like properties. Saying “explore”, “idea”, “might” makes it sound as if this was not a well-established 100-years-old theory. > My presumption is that atoms are somehow made of really high energy EM fields so that they appear to be massive. Somehow... The easiest way to proceed in that program of research may be to rename the standard model as ElectroMagnetism and try to get a unified theory of the strong, weak and the-force-previously-known-as-em forces. Then you unify that with GR and you’re done :-)
    - JadeNB 7y ago
      > The easiest way to proceed in that program of research may be to rename the standard model as ElectroMagnetism and try to get a unified theory of the strong, weak and the-force-previously-known-as-em forces. Certainly the unification of electromagnetism + the weak force is understood, and there is a theory (or several theories) about electroweak + strong unification: https://en.wikipedia.org/wiki/Grand_Unified_Theory https://en.wikipedia.org/wiki/Grand_Unified_Theory .
      - kgwgk 7y ago
        That links says: “Unsolved problem in physics: Are the three forces of the Standard Model unified at high energies?” But we may be close, for some values of close :-)
        JadeNB 7y ago
        > That links says: “Unsolved problem in physics: Are the three forces of the Standard Model unified at high energies?” Indeed, that's why I said only that there were theories about it.
        kgwgk 7y ago
        Sure, but the solutions to the solved problems in physics are also called "theories". I'm sure you knew the GUT is not yet done, it was just a clarification.
  - zaarn 7y ago
    Easy way to check, just wave a long piece of iron through the air. If there is truly a massive EM field, it should induce a decent voltage into said iron rod as it moves through the magnetic field lines produced by the "gravity EMism" Considering noone died from waving iron rods through the air by way of electrocution (other than lightning) I'd say that means gravity is not an EM field. There is also a different test: EM fields are either positive or negative in charge. If you have three objects, in an EM field they cannot all three attract eachother, one object must be pushed away from one of the other two. Considering we don't see that behaviour in our solar system, gravity cannot be an EM field.
    - deleted 7y ago
      [deleted]
    - 100ideas 7y ago
      I like your elegant thought experiment! Quarks have -1/3 or +2/3 charge in the standard model and presumably(?) at high enough energies they separate out into a quark-gluon plasma thus exposing the universe to their unholy fractional charges. Above 2 trillion Kelvin according to wikipedia.
      - zaarn 7y ago
        Even with fraction, either you have repulsion or attraction, depending on the sign. -1/3 charge will be repulsed by +1 or +2/3 charge, just at different strengths.
vectorEQ 7y ago
there's a whole field of science who believes gravity is just electromagnetic effect... it's just particle physicists who struggle with such notions...
- 100ideas 7y ago
  Well in the beginning there was just the one electro-strong-weak-gravity field... until inflation cooled everything down enough for the four “fundamental” forces to freeze out. Edit: ok so really there is only theoretical evidence of an electroweak field at the beginning (electromagnetic field and weak field are not independent at high energy) and everyone is currently hard at work trying to 1) figure out the “Grand Unified Theory” that will putatively integrate the strong force with the electroweak force, and 2) figure out how to rethink either gravity/spacetime in a quantum context to integrate it with the quantum GUT, or unquantize the GUT (not likely) so it can be combined with spacetime...

This is really interesting. Perhaps there is also a chance that electromagnetic fields are indeed entirely responsible for gravity, in some complicated yet unknown manner.

danbruc 7y ago

No, energy curves the gravitational field and there are other forms of energy than the energy of the electromagnetic field. For example, if you start walking, you gain kinetic energy and this will affect the gravitational field, not much but it will.

kgwgk 7y ago

What would that mean? As far as we know there is gravity in the absence of EM fields and EM energy produce gravitational effects just like other forms of energy (and in the realm of direct human experience the contribution of EM is negligible).

dschuetz 7y ago
"there is gravity in the absence of EM fields" That just cannot be true. EM fields are just about everywhere. They permeate space almost as universally as gravity, but in form of photons (to name higher energy EM fields here) or other low energy waves. Gravity accumulates with great masses, mass is also energy (in rest). The article explores the idea that pure kinetic energy in form of photons indeed might have at least gravity-like properties. My presumption is that atoms are somehow made of really high energy EM fields so that they appear to be massive. Consequently, atoms having mass or photons having inertia are responsible for gravitation, and that could mean that EM fields are the cause of gravity entirely. The problem with that presumption is that perhaps there is no way to check.
- danbruc 7y ago
  EM fields are just about everywhere. Fields are mathematical tools, they are not - without wanting to go down the philosophical rabbit hole - real things out there in the universe. And the thing about everything just being electromagnetic fields is nonsense, physicists understand physics way better than you do. Sorry to sound condescending, but the internet already has enough obviously wrong ideas by random people without a clue what they are talking but.
  - dschuetz 7y ago
    Dude, fields are a tool physicists use to describe phenomena. It's okay to say EM fields exist because they interact with everything everywhere and we can actually observe that.
    - 100ideas 7y ago
      The universe appears to have expanded or be expanding faster than the speed of light: the diameter of the observable universe is ~42 billion light-years but best estimates of age of universe is ~14 billion years. So these fields can’t interact with everything everywhere, only the portion of the universe In the field’s lightcone. if the universe keeps this up there’s a chance some day Everything will be so stretched out that the fields will be basically redshifted to null, so not interacting with anything anywhere. That’d be lame.
      - danbruc 7y ago
        [...] the diameter of the observable universe is ~42 billion light-years [...] That's the radius.
  - tsimionescu 7y ago
    Honest question: aren't radio waves "physical objects" that represent oscillations of an electro-magnetic field, to the best of our current understanding?
    - dschuetz 7y ago
      There is an agreement in physics that low energy EM fields are called waves, such as radio waves, and high energy EM fields are called photons or even particles. In any case they are actually both. If they are physical objects I don't know. I think, I wouldn't go that far.
      - 100ideas 7y ago
        Let’s talk virtual particles...
- tsimionescu 7y ago
  > EM fields are just about everywhere. They permeate space almost as universally as gravity Isn't dark matter most likely some kind of material that has mass, but no EM interaction? We also know that there are interactions inside atoms (the strong and weak forces) that have no known relation to electro-magnetism, so I'm not sure what you are getting at.
  - dschuetz 7y ago
    As far as I understand, dark matter is an educated guess (which was made upon the discovery that galaxies rotate differently than expected). Something out there must be causing gravity, but we cannot see it, which means that there is no observable EM interaction. The next guess here is that dark energy has a much much higher rest energy so that no photon in this universe is able to interact with it via EM fields. The search for dark matter was unsuccessful so far, and the LHC is still trying to achieve higher energies to be able to detect dark matter. So, dark matter is just a guess. The interactions inside atoms seem to have no known relations to EM, because, and this is my guess, there are much higher energies at work than we know. So, if dark matter is hiding behind high energies so that EM interaction seems impossible, why should it be different for EM interactions inside atoms. There still is a slim chance that it might be EM, just at much higher energies.
    - danbruc 7y ago
      The interactions inside atoms seem to have no known relations to EM [...] The electromagnetic and the weak interaction are known to be different aspects of the unified electroweak interaction. There are several grand unified theories and a few hints that at even higher energies the electroweak and strong interaction also unifiy into the electronuclear interaction. Due to the high energies involved, only indirect experimental evidence seems accessable for the forseeable future but there are various groups looking for hints. I am not aware of any uncontroversial results but there are a few non-reproducable experiments, for example observations of magnetic monopoles, which might be due to experimental error but also due to the rarity of magnetic monopoles.
- kgwgk 7y ago
  > The article explores the idea that pure kinetic energy in form of photons indeed might have at least gravity-like properties. Saying “explore”, “idea”, “might” makes it sound as if this was not a well-established 100-years-old theory. > My presumption is that atoms are somehow made of really high energy EM fields so that they appear to be massive. Somehow... The easiest way to proceed in that program of research may be to rename the standard model as ElectroMagnetism and try to get a unified theory of the strong, weak and the-force-previously-known-as-em forces. Then you unify that with GR and you’re done :-)
  - JadeNB 7y ago
    > The easiest way to proceed in that program of research may be to rename the standard model as ElectroMagnetism and try to get a unified theory of the strong, weak and the-force-previously-known-as-em forces. Certainly the unification of electromagnetism + the weak force is understood, and there is a theory (or several theories) about electroweak + strong unification: https://en.wikipedia.org/wiki/Grand_Unified_Theory https://en.wikipedia.org/wiki/Grand_Unified_Theory .
    - kgwgk 7y ago
      That links says: “Unsolved problem in physics: Are the three forces of the Standard Model unified at high energies?” But we may be close, for some values of close :-)
      - JadeNB 7y ago
        > That links says: “Unsolved problem in physics: Are the three forces of the Standard Model unified at high energies?” Indeed, that's why I said only that there were theories about it.
        kgwgk 7y ago
        Sure, but the solutions to the solved problems in physics are also called "theories". I'm sure you knew the GUT is not yet done, it was just a clarification.
- zaarn 7y ago
  Easy way to check, just wave a long piece of iron through the air. If there is truly a massive EM field, it should induce a decent voltage into said iron rod as it moves through the magnetic field lines produced by the "gravity EMism" Considering noone died from waving iron rods through the air by way of electrocution (other than lightning) I'd say that means gravity is not an EM field. There is also a different test: EM fields are either positive or negative in charge. If you have three objects, in an EM field they cannot all three attract eachother, one object must be pushed away from one of the other two. Considering we don't see that behaviour in our solar system, gravity cannot be an EM field.
  - deleted 7y ago
    [deleted]
  - 100ideas 7y ago
    I like your elegant thought experiment! Quarks have -1/3 or +2/3 charge in the standard model and presumably(?) at high enough energies they separate out into a quark-gluon plasma thus exposing the universe to their unholy fractional charges. Above 2 trillion Kelvin according to wikipedia.
    - zaarn 7y ago
      Even with fraction, either you have repulsion or attraction, depending on the sign. -1/3 charge will be repulsed by +1 or +2/3 charge, just at different strengths.

vectorEQ 7y ago

there's a whole field of science who believes gravity is just electromagnetic effect... it's just particle physicists who struggle with such notions...

100ideas 7y ago
Well in the beginning there was just the one electro-strong-weak-gravity field... until inflation cooled everything down enough for the four “fundamental” forces to freeze out. Edit: ok so really there is only theoretical evidence of an electroweak field at the beginning (electromagnetic field and weak field are not independent at high energy) and everyone is currently hard at work trying to 1) figure out the “Grand Unified Theory” that will putatively integrate the strong force with the electroweak force, and 2) figure out how to rethink either gravity/spacetime in a quantum context to integrate it with the quantum GUT, or unquantize the GUT (not likely) so it can be combined with spacetime...