Electrons Emitting Photons And Ambient Light

Click For Summary

Discussion Overview

The discussion revolves around the relationship between electrons, photons, and the nature of light as explained by quantum electrodynamics (QED). Participants explore whether the air around us is filled with electrons emitting photons and how QED relates to visible light, touching on foundational concepts in physics.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant questions if the air is filled with electrons emitting photons, expressing confusion about the visibility of air in darkness.
  • Another participant emphasizes that electrons do not emit photons unless they are in motion, suggesting that the question lacks clarity regarding the conditions under which photons are emitted.
  • There is a discussion about the limitations of popular science literature, with one participant noting that such books may omit crucial details necessary for a deeper understanding of QED.
  • One participant asserts that QED does explain visible light, while another suggests that a foundational understanding of classical electrodynamics is necessary before tackling QED concepts.
  • Suggestions are made for foundational topics to study, including classical electrodynamics, the ultraviolet catastrophe, and the quantum mechanical harmonic oscillator.

Areas of Agreement / Disagreement

Participants express differing views on the clarity and accuracy of the initial question regarding electrons and photon emission. There is no consensus on the understanding of QED or its implications for visible light, indicating ongoing debate and uncertainty.

Contextual Notes

Participants highlight the need for a solid grasp of classical physics concepts before engaging with QED, indicating that the discussion may be limited by varying levels of foundational knowledge among participants.

Who May Find This Useful

This discussion may be of interest to individuals exploring the fundamentals of quantum electrodynamics, the nature of light, and the relationship between classical and quantum physics.

D English
Messages
40
Reaction score
0
Ambient for lack of a better term...

I'm reading "Beyond The Cosmic Landscape". Perhaps out of date, but a very understandable explanation of QED.

Am I right to deduce that the air which surrounds us is jam-packed with electrons emitting photons?

Thanks...
 
Physics news on Phys.org
D English said:
Ambient for lack of a better term...

I'm reading "Beyond The Cosmic Landscape". Perhaps out of date, but a very understandable explanation of QED.

Am I right to deduce that the air which surrounds us is jam-packed with electrons emitting photons?

Thanks...

This is VERY confusing and puzzling if I take what you wrote literally.

Are you actually asking if the air particles are continually emitting photons, and this is all due to "jam-packed electrons"?

When you are out in complete darkness (and presumably, not in a vacuum), do you see the air somehow glowing in such darkness?

Zz.
 
ZapperZ said:
This is VERY confusing and puzzling if I take what you wrote literally.

Are you actually asking if the air particles are continually emitting photons, and this is all due to "jam-packed electrons"?

When you are out in complete darkness (and presumably, not in a vacuum), do you see the air somehow glowing in such darkness?

Zz.
I started thinking the same thing after I wrote it. Sorry-

I'm trying to connect the idea of QED (as I understand it) -that electrons emit photons- with the light that surrounds us, and I'm far from being able to articulate that intelligibly.

Perhaps the best way to say it is...does QED explain visible light?
 
D English said:
I started thinking the same thing after I wrote it. Sorry-

I'm trying to connect the idea of QED (as I understand it) -that electrons emit photons- with the light that surrounds us, and I'm far from being able to articulate that intelligibly.

Perhaps the best way to say it is...does QED explain visible light?

1. Why "visible light" in particular? That is such a small and restricted range of EM radiation.

2. I still don't understand this idea of "electrons emit photons". Will you drop flat on the floor if I tell you that protons can also be made to produce light? Or what about positrons and muons? I CAN make "electrons to emit light" by jigging it up and down (this is done in synchrotron centers all over the world), but this is well-known even from classical E&M (accelerating charged particles emit EM radiation). But if it is sitting still, minding its own business, it doesn't emit "light". So simply asking if "electrons emit photons" is vague, because it requires that the electrons have to DO something to emit light. And this applies to ALL charged particles.

3. I think you have a severe misunderstanding of QED, and I think you're coming in right in the middle of the story and missed the beginning of it. You may want to go several steps back and re-establish some basic foundation that we call can agree upon before trying to build on it.

Zz.
 
D English said:
I'm reading "Beyond The Cosmic Landscape". Perhaps out of date, but a very understandable explanation of QED.

Since this is a popular science book, not a textbook, its usefulness if you are actually trying to learn the science is limited. An explanation in ordinary language for lay readers is always going to leave out crucial information, and you won't be able to reason from it the way you can from knowledge of the actual science.

D English said:
does QED explain visible light?

The answer to this is easy: yes. Next question? :wink:

As @ZapperZ says, you might want to take a few steps back and start with something more basic than how QED explains a particular phenomenon.
 
PeterDonis said:
Since this is a popular science book, not a textbook, its usefulness if you are actually trying to learn the science is limited. An explanation in ordinary language for lay readers is always going to leave out crucial information, and you won't be able to reason from it the way you can from knowledge of the actual science.
The answer to this is easy: yes. Next question? :wink:

As @ZapperZ says, you might want to take a few steps back and start with something more basic than how QED explains a particular phenomenon.
Thanks Peter. I thought I had stumbled upon a revelation and got excited. I needed feedback.

What would you suggest as a good few steps back"?

A statement of qualification, as I am bound to come up with more dumb questions. I will never come here looking for an argument, and I will never have a firm grasp of any of this. My life path brought me to a life of service, not advanced learning. I never knew what I was missing until -by chance- I picked up a book written by a guy in a wheelchair. Never the less, I will try to have a deeper understanding of what I observe, and will be drawn to places that fuse science and community. I think Dick Feynman would encourage that.
 
D English said:
What would you suggest as a good few steps back"?
One plausible approach: first, be sure that you have a solid grasp of classical electrodynamics and how electromagnetic radiation, including light, is a consequence of Maxwell's equations. Then read about the "ultraviolet catastrophe" and how Max Planck resolved it (without any recourse to the modern understanding of quantum mechanics, because that didn't come for another quarter-century). From there you can switch tracks and learn about the quantum mechanical solution to the harmonic oscillator... and then take on some of our many threads about "what is a photon".
 
Nugatory said:
One plausible approach: first, be sure that you have a solid grasp of classical electrodynamics and how electromagnetic radiation, including light, is a consequence of Maxwell's equations. Then read about the "ultraviolet catastrophe" and how Max Planck resolved it (without any recourse to the modern understanding of quantum mechanics, because that didn't come for another quarter-century). From there you can switch tracks and learn about the quantum mechanical solution to the harmonic oscillator... and then take on some of our many threads about "what is a photon".
Is that all? :)

Thanks for the guidance.
 

Similar threads

  • · Replies 19 ·
Replies
19
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 38 ·
2
Replies
38
Views
7K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 0 ·
Replies
0
Views
461
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 36 ·
2
Replies
36
Views
8K