Is the Universe neutrally charged?

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Discussion Overview

The discussion centers around the concept of charge neutrality in the universe, particularly at the time of the Big Bang and during the early universe's evolution. Participants explore the implications of charge conservation and the transition from energy to matter, as well as the consequences of these ideas in high-energy physics experiments.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants question whether there are exactly as many negative charges as positive charges in the universe and seek rationale behind the assumption of charge neutrality at time zero.
  • Concerns are raised about the implications of a non-neutral universe on counting electric force lines connecting charges.
  • Several participants discuss theories of the early universe, including inflation and the decay of the inflaton field into standard model particles, suggesting that charge conservation would lead to a neutrally charged universe.
  • There is a proposal that if energy is converted into matter, the resulting matter must maintain charge neutrality due to conservation laws, leading to the idea that charged particles must balance out in any reaction.
  • Questions are posed about the implications of a proton's mass and whether it can be entirely converted to energy, alongside discussions about energy conservation in particle interactions.
  • Some participants clarify that energy is not a physical entity that can be converted but rather a conserved quantity that can be observed in interactions.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of charge neutrality and energy conservation, with no clear consensus reached. Some agree on the conservation laws governing particle interactions, while others remain uncertain about the implications of these laws in the context of the universe's charge state.

Contextual Notes

Limitations in the discussion include assumptions about the early universe's conditions, the definitions of energy and charge, and the unresolved implications of high-energy particle interactions.

cmb
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TL;DR
Are there exactly as many negative charges as positive, in the universe?
Are there exactly as many negative charges as positive, in the universe?

If so, how can we be sure, and if not then what is the difference and why?

If there is an assumption of charge neutrality at time zero, then why? Is there a rationale behind that or just an unsupported supposition?
 
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If not neutral we have difficulty in counting lines of electric force which connects positive and negative charges. I do not say it is reason why but I am feeling uneasy about it.
 
cmb said:
If there is an assumption of charge neutrality at time zero, then why? Is there a rationale behind that or just an unsupported supposition?
Theories on the composition and evolution of the very, very early universe typically involve a transition from a higher energy state to a lower energy state. For example, inflation proposes that the very early universe contained an inflaton field, a field which contained a large amount of energy. After inflation this field decayed into the standard model particles and their corresponding fields. This decay process would likely have been governed by many different conservation laws, including charge conservation, ensuring a neutrally charged universe.
 
Drakkith said:
Theories on the composition and evolution of the very, very early universe typically involve a transition from a higher energy state to a lower energy state. For example, inflation proposes that the very early universe contained an inflaton field, a field which contained a large amount of energy. After inflation this field decayed into the standard model particles and their corresponding fields. This decay process would likely have been governed by many different conservation laws, including charge conservation, ensuring a neutrally charged universe.
OK, that is fine as an explanation, happy with that I was thinking that might be one of the possibilities.

So, basically, if we have 'energy' and, by whatever means, it is converted into matter, if any of that matter is made up of charged particles then it's ALWAYS as much charge of each polarity because the 'energy' was not charged thus the product mass cannot be charged, by conservation of charge?

And this is what we see in real high energy experiments? So if we wham, say, two protons together it cannot produce 'only' energy but all the products still have to tot up to two units of charge?

But does that mean a proton alone can never be 'entirely' converted to energy? If so, what does that mean in reaction to expressing its mass in MeV, if it cannot be all converted to energy?
 
cmb said:
But does that mean a proton alone can never be 'entirely' converted to energy? If so, what does that mean in reaction to expressing its mass in MeV, if it cannot be all c
Energy is not a thing that you can convert to or from. https://www.feynmanlectures.caltech.edu/I_04.html Instead, it is a number that you can compute and can observe to be conserved.

You can convert between various things and observe that energy is conserved. In particular, if we had a pair of oppositely moving photons with enough combined energy, we could collide them (photon-photon interaction) and produce a proton plus anti-proton pair with the same total energy. Easier, if we had a proton and anti-proton pair, we could collide them and get a result with the same total energy.
 
jbriggs444 said:
Energy is not a thing that you can convert to or from.
Could you please help me understand that in the context of Drakkith's response?

Drakkith said:
... inflation proposes that the very early universe contained an inflaton field, a field which contained a large amount of energy. After inflation this field decayed into the standard model particles and their corresponding fields...
 
cmb said:
Could you please help me understand that in the context of Drakkith's response?
There was a field. Then there were standard model particles. To the extent that energy conservation applies, the energy of both was the same.
 

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