Energy, charge and electric field

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Discussion Overview

The discussion revolves around the relationship between electric fields, energy, and the creation of particles, particularly in the context of an electron appearing in space. Participants explore the implications of charge conservation and the nature of particle creation, touching on concepts from quantum mechanics and particle physics.

Discussion Character

  • Exploratory, Debate/contested, Conceptual clarification

Main Points Raised

  • One participant questions the change in energy associated with an electric field when an electron appears, noting that the electric field propagates at the speed of light.
  • Another participant argues that the scenario presented violates conservation of energy, suggesting that charges cannot appear without being transported from elsewhere.
  • A participant references the decay of a neutron into a proton and electron, proposing that particles can be generated in a previously empty space, although they acknowledge limited knowledge on the topic.
  • Some participants assert that charge conservation requires a positively charged particle to be created alongside an electron, maintaining that the total charge remains constant.
  • There is a discussion about whether the electron and proton must be created at the same position, with some asserting they can only be at the same spot for an infinitesimal amount of time due to their subsequent motion.
  • Participants mention that in quantum mechanics, particles exist in a cloud of probability, complicating the notion of them being in a single location simultaneously.
  • One participant introduces the concept of pair production, indicating that an electron and a positron (anti-electron) are typically created together rather than an electron and a proton.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of particle creation in the described scenario, with some asserting the necessity of charge conservation while others question the implications of such conservation in the context of quantum mechanics. The discussion remains unresolved regarding the specifics of particle creation and the associated energy changes.

Contextual Notes

Participants exhibit varying levels of understanding of quantum mechanics and particle physics, leading to potential misunderstandings about the nature of particle interactions and energy conservation. The discussion reflects a mix of high school-level concepts and more advanced theoretical considerations.

GAURAV DADWAL
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Hi there,

Im familiar with the concept that electric field has associated energy with it
Now if in space an electron apppeared at some instant t=0 then electric field will not be established instantaneously but will propagate at speed of light through space
As electric field is bieng established energy associated with it is changing with time
Now what is causing that change in energy although there is no change in charge placed there and no other interaction are seeming to be there to cause change in energy .pls help me understand this .
Any help will be appreciated
 
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The problem is that you created an unphysical scenario (if I understand it correctly, your wording is very confusing). Charges don't just appear magically in place, they need to be transported in from somewhere else. That is, your scenario directly violates the conservation of energy, but your question is exactly about that aspect, the total energy.
 
In high school we are taught about decay of neutron into proton and electron with antineutrino .
I have just passed high school so i am not having enough knowledge but still i think that in this process proton and electon are generated instantaneously in the space which initially was having no charge particles and also i think these are not generated at same place .
So i think my question makes some sense
 
While particles can indeed be created out of energy, the total sum of charge however is conserved, just like energy:

https://en.m.wikipedia.org/wiki/Charge_conservation

So, you can't just create an electron from energy, there *has* to be a positive charged particle created at the same time to keep the total sum the same.
 
, there *has* to be a positive charged particle created at the same time to keep the total sum the same.[/QUOTE]

Is that positively charged particle has to be formed at the same position as that of electron?
 
Yes.
 
I didn't get that ??
How can electon and proton be at same position at same time
 
They are only in the same spot for an infinitesimal small amount of time, since they are flying away from each other. Look into how particle accelerators work, that's really the same principle.

Also, IIRC you can't create an electron and a proton on their own. I believe the latter would have to be a positron (i.e. an anti-electron)
 
Why are they flying apart as attractive force between them will be infinite when they are at same position
 
  • #10
When it comes to these things, you can't look at it from a classical, static point of view. This is quantum mechanics, where particles aren't exactly in one spot but rather exist in a cloud of probability, and they also often have a large kinetic energy.

https://en.wikipedia.org/wiki/Pair_production
 
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  • #11
GAURAV DADWAL said:
How can electon and proton be at same position at same time

It's the same principle with how particle accelerators work :wink:
 
Last edited:

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