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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 t

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...
    - danbruc 7y ago
      They are also just in the models and heads of physicists.
  - tsimionescu 7y ago
    Sure, they are both, but my point was - if they have wave-like characteristics, they must be a wave of/in something; if we can have experimental evidence that the wave exists, I would consider that experimental evidence that the field the wave is a wave of must also exist, to the same extent.
- danbruc 7y ago
  Radio waves are streams of photons, the fields are just a mathematical tool we use to describe this. And there are several of them, the classical electromagnetic field but also an entire set of fields involved in the quantum version.
  - kgwgk 7y ago
    Other people may say that photons are just mathematical tools that we use to describe fields. :-)
    - danbruc 7y ago
      The fact that gauge fields have redundant degrees of freedom should at least be a strong hint that the fields are not the fundamental description. ;)
cycomanic 7y ago
Well by saying that fields are not "real things" you have just started going down the "philosophical rabbit hole". What is a real thing, is the gravitational force that we feel not a real thing, is the energy we feel in an EM wave (e.g. The sun on our skin) not a real thing?
- 100ideas 7y ago
  What, you don’t think the Hylaean Theoric World is realer that reality?

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...
  - danbruc 7y ago
    They are also just in the models and heads of physicists.
- tsimionescu 7y ago
  Sure, they are both, but my point was - if they have wave-like characteristics, they must be a wave of/in something; if we can have experimental evidence that the wave exists, I would consider that experimental evidence that the field the wave is a wave of must also exist, to the same extent.
danbruc 7y ago
Radio waves are streams of photons, the fields are just a mathematical tool we use to describe this. And there are several of them, the classical electromagnetic field but also an entire set of fields involved in the quantum version.
- kgwgk 7y ago
  Other people may say that photons are just mathematical tools that we use to describe fields. :-)
  - danbruc 7y ago
    The fact that gauge fields have redundant degrees of freedom should at least be a strong hint that the fields are not the fundamental description. ;)

cycomanic 7y ago

Well by saying that fields are not "real things" you have just started going down the "philosophical rabbit hole". What is a real thing, is the gravitational force that we feel not a real thing, is the energy we feel in an EM wave (e.g. The sun on our skin) not a real thing?

100ideas 7y ago
What, you don’t think the Hylaean Theoric World is realer that reality?