Can a region of space-time be created with no ER?

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Discussion Overview

The discussion revolves around the possibility of creating a region in space-time devoid of electromagnetic (ER) fields and photons. Participants explore theoretical constructs and implications related to electromagnetic fields, vacuum states, and quantum mechanics.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • Some participants propose that a photon is an excitation of the electromagnetic field, suggesting that a region without photons implies a lack of ER fields.
  • There is a question about whether a field strength of zero constitutes "no EM field," with references to vacuum fluctuations complicating this notion.
  • One participant mentions that a small hole in a superconductor could potentially create a region with no photons, implying a specific condition for achieving this state.
  • Another participant raises concerns about the definitions of "calm ER fields" and whether they can coexist with the absence of detectable ER fields or photons.
  • It is noted that a calm field at absolute zero is theoretically impossible due to the third law of thermodynamics, yet quantum mechanics suggests residual oscillations due to zero point energy.
  • Participants assert that virtual photons will always exist, indicating that the concept of a "true vacuum" may conflict with Heisenberg's Uncertainty Principle.

Areas of Agreement / Disagreement

Participants express differing views on the definitions and implications of "calm ER fields," the feasibility of creating a region without photons, and the nature of vacuum states. No consensus is reached on these points.

Contextual Notes

The discussion highlights limitations in definitions and assumptions regarding electromagnetic fields, vacuum fluctuations, and the implications of quantum mechanics on the concept of a true vacuum.

San K
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A photon may be considered as an excitation of the electromagnetic (ER) field.

ER is thought to be omnipresent/ubiquitous in time-space (?)

Is it possible to construct a region in space-time (say a "black" box):1. That contains no ER fields?
2. that contains no photons? i.e. no excitation/energy...just a peaceful region with "calm" ER fields
 
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If the field strength is zero, does that count as "no EM field"?
Do you count vacuum fluctuations? If you do, it is impossible (see the Casimir effect).

2. that contains no photons? i.e. no excitation/energy...just a peaceful region with calm ER fields
A small hole in a superconductor, cooled sufficiently... should work.
 
I think, as mfb implies, a lot depends on just what you mean:

A photon is a quanta of an electromagnetic field, that is, a locally detectable manifestation of ER... a locally observable field quantity, while the field is a mathematical construct, not observable.

I don't think any ER is detectable in space unless from an external source. I suspect that is what mfb's small hole in a superconductor implies??

This seems contradictory:
1. That contains no ER fields?
2. that contains no photons? i.e. no excitation/energy...just a peaceful region with calm ER fields

Is a 'calm ER field' 'no ER field'...'calm' is not a term I have seen in these forums. Do you make a distinction between 'no ER' and 'no photons' and 'calm ER fields' ??

You are perhaps thinking of 'detectable' ER...??

You can get rid of most detectable ER with a Faraday cage, but your question may go beyond that to vacuum energy.
 
A calm field doesn't mean no field just as a calm ocean doesn't mean no water. Anyways, a calm field will happen at zero Kelvin (in classic physics) which is impossible by the 3rd law of Thermodynamics. Clasic physics isn't exact though and in Quantum physics even at zero Kelvin there would be some oscillation left on the fields due to zero point energy
 
There will always be virtual photons.
The problem is that a "true vacuum" is too specific and would violate Heisenberg Uncertainty.
 

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