Photon Interactions with Matter: Explained

  • Context: Graduate 
  • Thread starter Thread starter etepperman
  • Start date Start date
  • Tags Tags
    Matter Photons
Click For Summary

Discussion Overview

The discussion centers around the interactions of photons with matter, particularly why photons do not pass through matter in the same way as neutrinos, despite having no charge. Participants explore the nature of these interactions, the role of electromagnetic forces, and the implications of photon behavior in various contexts.

Discussion Character

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

Main Points Raised

  • Elliott questions why photons do not pass through matter like neutrinos, seeking to understand what they interact with when stopped by matter.
  • Some participants assert that photons interact electromagnetically, primarily with charged particles such as protons and electrons, which are constituents of matter.
  • There is a discussion on the nature of electromagnetic interactions, with some participants explaining that photons mediate the electromagnetic force between charged particles.
  • Several participants express confusion regarding how photons, having no charge, can interact with electromagnetic forces, prompting further clarification on the concept of photons as quanta of electromagnetic energy.
  • One participant emphasizes that electromagnetic waves transfer energy in discrete amounts and that the oscillations of these waves exert forces on charged particles.
  • Another participant suggests a shift in perspective, indicating that charges interact with the electromagnetic field rather than directly with each other.

Areas of Agreement / Disagreement

Participants express varying levels of understanding regarding the nature of photon interactions, with some agreeing on the electromagnetic nature of these interactions while others remain uncertain about the implications of photons having no charge. The discussion does not reach a consensus on the conceptual framing of these interactions.

Contextual Notes

Participants highlight the dependence on definitions of charge and electromagnetic interactions, and there are unresolved questions about the nature of photons and their role in mediating forces.

etepperman
Messages
2
Reaction score
0
Hi,

Why do photons not pass through matter like neutrinos since they have no charge. What are they interacting with when they are stopped by matter?

Thanks,
Elliott
 
Science news on Phys.org
etepperman said:
Hi,

Why do photons not pass through matter like neutrinos since they have no charge. What are they interacting with when they are stopped by matter?

They have no charge, but they interact electromagnetically - in fact, that's about the only thing they do.
 
as above photons, interact electromagnetically with two very important particles that create up 'matter' in the universe protons and electrons. these are charged. Neutrinos have an extremely low to nil mass and only interact with matter via the weak force which has a very small range.
 
If they have no charge how is it that they interact with the electromagnetic forces?
 
light is electromagnetic radiation. when photons makes contact with matter it transfers its energy to the particles in the matter. There is a finite probability of a photon passing through matter, this is all dependent on characteristics of the photons and matter its passing/making contact with, e.g. type of matter(more densely packed atoms have higher chance to come in contact with photons. And or photon energy.

A usual/interesting thing for you to research on maybe electron energy levels and spectroscopy.

Also research fundamentally why we call light "Electromagnetic Radiation"
 
etepperman said:
If [photons] have no charge how is it that they interact with the electromagnetic forces?

They are the electromagnetic force, in the sense that they mediate the electromagnetic force between two charged particles via exchange of virtual photons. The two charged particles don't change their charge in the process, so the photon itself must not have any charge.
 
etepperman said:
If they have no charge how is it that they interact with the electromagnetic forces?

From the wording you are using, it's possible that you are trying to think in terms of photons being 'particles' in the conventional sense of the word, rather than quantum particles. Personally, I think it was an unfortunate choice of word for the Quantum of EM Energy.
 
etepperman said:
If they have no charge how is it that they interact with the electromagnetic forces?

Photons are not simply little particles with zero electric charge. They are the quanta of energy that an EM wave interacts with matter by. In other words, an EM wave, which is an oscillation in the electric and magnetic fields, transfers energy only in discrete amounts. The oscillations exert an alternating electric force on charged particles. In fact, the oscillations themselves are in the vectors that represent the direction and magnitude of the force on charged particles.
 
etepperman said:
If they have no charge how is it that they interact with the electromagnetic forces?

Rather than thinking that charges interact with charges, know that charges can only interact with the electromagnetic field. When someone says that charges interact with charges it is implied or taken for granted that they do so via the electromagnetic field.
 

Similar threads

Undergrad How large is the volume of a photon interacting with matter?
  • · Replies 15 ·
Replies
15
Views
2K
Graduate Do photons of different energies interact with each other?
  • · Replies 6 ·
Replies
6
Views
2K
Graduate The attractive force of photons on other photons & matter
  • · Replies 5 ·
Replies
5
Views
17K
Undergrad How prone is a photon to interacting with uncharged structureless particles?
  • · Replies 8 ·
Replies
8
Views
3K
Graduate How Does Light-Matter Interaction Challenge Classical and Quantum Views?
  • · Replies 7 ·
Replies
7
Views
3K
High School Matter density right after the decoupling
  • · Replies 13 ·
Replies
13
Views
1K
Graduate Why there isn't a scattered photon in the Pe effect?
  • · Replies 6 ·
Replies
6
Views
2K
Graduate The reality of photons (real vs virtual etc)
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Faraday effect breaks photon interaction laws
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad Photon Detection: Learn About Interaction, Detection & Angles
  • · Replies 24 ·
Replies
24
Views
3K