Do electric fields also generate smaller electric fields?

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Discussion Overview

The discussion revolves around the nature of electric fields and whether they can generate smaller electric fields. Participants explore the implications of charged objects creating electric fields and the potential for these fields to interact and induce additional fields in various contexts.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • A participant questions the reasoning behind the idea that electric fields could generate other electric fields, based on their teacher's explanation that fields themselves are charged.
  • Another participant suggests that fields do not possess charge and recommends seeking clarification from the teacher regarding their statement.
  • One participant points out a potential misunderstanding regarding field lines, noting that the assertion that field lines repel each other is misleading and could lead to the conclusion that fields have charge.
  • A later reply explains that while fields themselves do not contain charge, they can induce secondary fields when interacting with matter, such as in the case of polarization in dielectrics, leading to a complex interaction of fields.

Areas of Agreement / Disagreement

Participants express differing views on the nature of electric fields and their ability to generate other fields. There is no consensus on the implications of the teacher's explanation or the correctness of the initial reasoning presented by the first participant.

Contextual Notes

Some statements rely on specific definitions of electric fields and charge, and the discussion includes assumptions about the behavior of fields in various contexts, such as in dielectrics, which may not be fully resolved.

polaris12
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*first time posting on here*

Hi, firstly I am a high school junior taking physics and I find it very interesting and plan to major in it. Now, today my teacher was explaining electric fields and said that all charged objects generate them around themselves. He then said that fields themselves were charged. After thinking about it, I realized that if this were true, then there should be electric fields made by other fields, ad infinitum. Firstly, is my reasoning correct, and secondly, if it is not, what was my mistake?

thanks in advance
 
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polaris12 said:
He then said that fields themselves were charged.
You need to ask him to clarify what he meant. Fields don't have charge.
 
he showed us a diagram where there was a positively charged rod near a negatively charged rod. he then drew field lines, and the ones on the outside were curved outward because they were repelling, according to him, which I assume means they have charge. Exactly where is the mistake in this reasoning?
 
polaris12 said:
he showed us a diagram where there was a positively charged rod near a negatively charged rod. he then drew field lines, and the ones on the outside were curved outward because they were repelling, according to him, which I assume means they have charge. Exactly where is the mistake in this reasoning?
The first mistake is the statement that the field lines are repelling each other. That seems an odd thing to say. I can see how that might lead you to conclude that fields have charge, if you think that only charges can repel.

Charges are surrounded by electric (and, if moving, magnetic) fields, but the fields themselves do not contain charges.
 
But, in a manner that you are not intending, the fields do generate secondary fields when they interact with matter. For example, if I induce an electric field across a dielectric, I cause polarization within the dielectric. That is, the molecules inside the dielectric become dipoles, the charges in the molecules shift slightly so that there is a local positive and local negative charge. This causes a secondary electric field and, when added to the original field that I induced, gives you the total field that you observe when you place the dielectric into the original field.

So fields can induce secondary fields, which induce tertiary fields, and so forth. Not because the fields are charged, but because any existing charges in the environment subjected to these fields respond to the fields and can create new fields.
 

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