How can photons interact if they travel at the speed of ligh

Click For Summary
SUMMARY

The discussion centers on the interaction of photons and neutrinos, specifically addressing the misconception that massless particles, such as photons, cannot interact due to their speed. Participants clarify that while photons travel at the speed of light, they can still interact and change states, as demonstrated in Feynman diagrams. The conversation also touches on neutrino oscillations, emphasizing that mass eigenstates can acquire different phases, which is crucial for understanding their behavior. The podcast referenced discusses the solar neutrino problem and the implications of neutrino mass.

PREREQUISITES
  • Understanding of quantum mechanics principles
  • Familiarity with Feynman diagrams
  • Knowledge of neutrino oscillations
  • Basic concepts of particle physics
NEXT STEPS
  • Research the solar neutrino problem and its implications on particle physics
  • Study the concept of neutrino oscillations in detail
  • Learn about Feynman diagrams and their role in particle interactions
  • Explore the properties of massless particles and their interactions
USEFUL FOR

Physicists, students of quantum mechanics, and anyone interested in the interactions of fundamental particles and the implications of neutrino mass.

freetheparticle
Messages
3
Reaction score
0
I was listening to a podcast about the solar neutrino problem, and they discussed how we have deduced that neutrinos are not massless due to the fact that they interact with other particles (even if this interaction occurs rarely). I paraphrase: "a particle traveling at the speed of light is frozen in time and is frozen in its state. It can never change states." If that is the case, then how come we can see photons coming into and out of existence on Feynman diagrams? If they travel at the speed of light how is it possible for them to interact and change states?
 
Physics news on Phys.org
You are misinterpreting what they are saying. They are not saying a massless particle cannot interact. They are also hugely oversimplifying what neutrino oscillations are.
 
Orodruin said:
You are misinterpreting what they are saying. They are not saying a massless particle cannot interact. They are also hugely oversimplifying what neutrino oscillations are.
What do you think they mean by "frozen in its state"?
 
greswd said:
What do you think they mean by "frozen in its state"?

A more accurate (although still very over simplified) description would be that if all the mass eigenstates travel at the same velocity, which they would if they were massless, they cannot acquire a relative phase. It is the mass eigenstates acquiring different phases that is the basis of neutrino oscillations.
 
  • Like
Likes   Reactions: mfb
freetheparticle said:
I was listening to a podcast about the solar neutrino problem, and they discussed how we have deduced that neutrinos are not massless due to the fact that they interact with other particles (even if this interaction occurs rarely). I paraphrase: "a particle traveling at the speed of light is frozen in time and is frozen in its state. It can never change states." If that is the case, then how come we can see photons coming into and out of existence on Feynman diagrams? If they travel at the speed of light how is it possible for them to interact and change states?

which podcast is this?
 

Similar threads

Undergrad How prone is a photon to interacting with uncharged structureless particles?
  • · Replies 8 ·
Replies
8
Views
3K
Graduate Neutrinos and Conservation Laws
  • · Replies 23 ·
Replies
23
Views
4K
Undergrad How Does Beta Decay Relate to the Role of W Bosons in Weak Nuclear Force?
  • · Replies 4 ·
Replies
4
Views
4K
Undergrad Electroweak Feynman Rules: Confusion about the photon-W boson interaction term
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad How do the collider experiments measure the mass of the W boson?
  • · Replies 4 ·
Replies
4
Views
4K
High School A photon always travels in a black hole
  • · Replies 9 ·
Replies
9
Views
1K
Undergrad How can Gluon travel at speed of light?
  • · Replies 19 ·
Replies
19
Views
4K
High School Let me ask a thing about the Speed of Light
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Are all massless particles "born" at light speed?
  • · Replies 11 ·
Replies
11
Views
3K
Graduate Nutrino Mass and Oscillation problem
  • · Replies 10 ·
Replies
10
Views
3K