Particles/waves that self-propogate

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Discussion Overview

The discussion revolves around the concept of self-propagating particles, specifically focusing on photons and their behavior. Participants explore the definitions and implications of self-propagation in the context of physics, including the relationship between momentum, energy, and the speed of light.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether photons self-propagate and if they must travel at the speed of light.
  • Another participant seeks clarification on the meaning of self-propagation, suggesting that a particle in motion continues until acted upon by a force, which may not align with the concept of self-propagation.
  • A later reply expresses a realization about the laws of motion, indicating a shift in understanding but does not contribute further to the discussion.
  • Further exploration is presented regarding whether a photon self-propagates due to its momentum or through electromagnetic field interactions, raising questions about the implications of Einstein’s and Planck’s equations.
  • Another participant discusses the particle-like behavior of light, emphasizing that it transmits discrete amounts of energy and suggesting that the Doppler effect indicates wave-like behavior rather than constant momentum.

Areas of Agreement / Disagreement

Participants express differing views on the nature of self-propagation, with no consensus reached on whether photons self-propagate or how to define the concept in relation to motion and forces.

Contextual Notes

There are unresolved definitions regarding self-propagation and its implications, as well as dependencies on interpretations of physical laws and equations.

zewpals
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Are there self-propagating particles? Does a photon, for instance, self-propagate? If so, is it required that they travel the speed of light?
 
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What does self-propagate mean? A particle in motion will remain in motion until a force acts upon it. I am not sure if that counts as self propagating.
 
Wow, I cannot believe I completely ignored that law. Haha thanks. This thread is over now :D
 
zewpals said:
Does a photon, for instance, self-propagate? If so, is it required that they travel the speed of light?

By way of a footnote: Does a photon self-propagate due to its momentum or as an E-B field interaction? If a photon is assumed to travel at [c], it has no rest mass [tex][m_0=0][/tex], so what are the implications of the following composite of Einstein’s and Planck’s equations?

[tex]E=mc^2=\sqrt{m_0^2c^4+\rho^2c^2} \Rightarrow \rho c = hf[/tex]

If [h] and [c] are treated as constants, then momentum is directly proportional to frequency. Possibly the attached cartoon puts it all into perspective:smile:
 

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I thought that the particle-like behavior of light was that it transmits discrete amounts of energy, i.e. the amount of energy it carries is not continuously variable. I think the doppler effects light is susceptible to indicate that it behaves more like a wave than a particle of matter with constant momentum once in motion and unaffected by exogenous forces.
 

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