What gives photons the energy to move at the speed they do

  • Context: Undergrad 
  • Thread starter Thread starter MaoIragorri
  • Start date Start date
  • Tags Tags
    Energy Photons Speed
Click For Summary

Discussion Overview

The discussion centers around the question of what gives photons the energy to travel at their characteristic speed, exploring the nature of photons, their energy sources, and the implications of their mass properties. The scope includes conceptual and theoretical aspects of photon behavior in physics.

Discussion Character

  • Conceptual clarification, Technical explanation, Debate/contested

Main Points Raised

  • Some participants assert that photons always travel at the speed of light due to their massless nature.
  • Others propose that a photon is essentially pure kinetic energy and that it travels at light speed from the moment of its creation.
  • A participant questions the phrasing of the original question, suggesting it may be seeking to understand the source of a photon's energy, providing examples such as electron transitions in atoms and nuclear decay as sources of photon emission.
  • There is mention of specific processes, like an electron dropping to a lower energy state or a moving electron striking a metal, which can result in the emission of photons.

Areas of Agreement / Disagreement

Participants express differing views on the nature of photons and their energy sources, indicating that multiple competing perspectives exist without a clear consensus.

Contextual Notes

Some statements rely on specific interpretations of mass and energy, and the discussion does not resolve the complexities surrounding the definitions of massless particles or the conditions under which photons are emitted.

MaoIragorri
Messages
6
Reaction score
0
I have a question...
what gives photons the energy to move at the speed they do?
 
Physics news on Phys.org


Photons always travel at the speed of light, regardless of their energy, because they are massless.
 


A photon is pure kinetic energy. It alway travels at the speed of light, from the moment it is created. It's more accurate to say a photon has no rest mass than to say that it's massless.
 


In wording that "what gives photons the energy", I wonder if the intent was to ask where the energy came from. There is always a source of the energy. If an electron in an atom drops to a lower energy state, for example, making a transition from the n=2 quantum number to the n=1 quantum number, it emits one photon. A nucleus that is in an excited state sometimes falls to a lower energy state, and gives off a gamma ray. An x-ray is given off when a moving electron hits a metal and loses its kinetic energy.
 

Similar threads

Undergrad Lost Energy from a Reciprocating Piston
  • · Replies 31 ·
2
Replies
31
Views
4K
Graduate Can energy conservation be violated?
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Same old question, I still don't get it: E=1/2mv^2 - more E with V?
  • · Replies 41 ·
2
Replies
41
Views
4K
High School Conceptually understanding change in potential energy with 0 net work
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad Alive in one frame and dead relative to other?
  • · Replies 50 ·
2
Replies
50
Views
4K
Undergrad Energy requirements of a 4 wheel drive boat
  • · Replies 20 ·
Replies
20
Views
2K
Graduate Photon Momentum/Energy: Is It Equal?
  • · Replies 9 ·
Replies
9
Views
3K
Graduate Is kinetic energy included in the equation E = hν for a photon?
  • · Replies 19 ·
Replies
19
Views
3K
Graduate How photons exceeds their velocity?
  • · Replies 25 ·
Replies
25
Views
4K
Undergrad Car, gas and total energy calculation
  • · Replies 3 ·
Replies
3
Views
1K