All Questions
22 questions
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65
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Do interactions slow down a particle? [closed]
I wonder whether particles, especially such as photons and neutrinos, do slow down when they interact in any way? E.g. how is it going on for the Compton effect but how is it in general like in QED or ...
- 1,537
20
votes
2
answers
7k
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Sun light takes 1,000/30,000/100,000/170,000/1,000,000 years bouncing around inside to then reach the Earth
When light (photon particle) is generated inside the Sun, it takes a long time to bounce around inside to later escape and travel outwards.
Neutrinos escape immediately.
The numbers for the years ...
- 548
3
votes
1
answer
222
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Is there a probability that a neutrino and anti-neutrino transform into two photons?
A neutrinos and an anti-neutrino can meet, form a virtual $Z^0$, which subsequently can create a new pair of leptons.
Now, an electron-anti-electron pair can do the same, but they can create two ...
- 81
6
votes
1
answer
584
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Photon Phase vs Time Evolution
If it is said that photons do not experience time or distance because they travel at light speed, then how can photons get out of phase with one another due to different path lengths? How can phase ...
- 11.2k
0
votes
0
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37
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How can neutral elementary particles have spin magnetic moment? [duplicate]
The spin magnetic moment of a particle is proportional to q/2m, where q and m are charge and mass of the particle respectively. So if an elementary particle is neutral (like neutrinos or photons), ...
- 903
0
votes
1
answer
89
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Neutrino temperature
I was wondering if anybody knows the relation between the photon temperature $T$ and neutrino temperature $T_{\nu}$? And why this can be written as
$$T_{\nu}=\left(\frac{4}{11}\right)^{1 / 3} T \...
- 1
2
votes
1
answer
135
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Photon - Neutrino interaction
Suppose we have a laser source, that means a coherent laser beam formed by 'in phase' photons. Is it possible to calculate how many photons can change their wavelength in neutrino - photon interaction ...
- 603
-2
votes
2
answers
70
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If photons evolve over time, how can they not have mass?
I was reading about the reason why we think neutrinos have mass, and it said that because they evolve over time, they must have mass because they feel the flow of time.
But don't photons also evolve ...
- 369
0
votes
2
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126
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Do neutrinos not interact with any kind of photons?
If billions of neutrinos reach us from the Sun why there is no any reflection of photons emitted from Earth to be reflected from them?
Is this they are not interacting at all?
- 1,835
0
votes
1
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179
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How can individual neutrinos have different amounts of energy?
Photons have no mass, travel at the speed of light, and their energy is related to their frequency.
Neutrinos have a very small mass, travel at almost the speed of light; what is their energy related ...
3
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0
answers
110
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Which Particle would win the race?
I have read this question:
Neutrinos vs. Photons: Who wins the race across the galaxy?
https://en.wikipedia.org/wiki/Neutrino
And it made me curious.
The wiki article says that neutrinos travel at ...
- 29.3k
1
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2
answers
7k
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Can a photon decay?
If supposedly someone is to argue that photon might be carrying a mass which is much smaller than our current detector can measure, and it could decay into something that moves at the speed of true ...
- 13.1k
-2
votes
1
answer
833
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Similarities between photons and neutrino? [closed]
Are there any similarities between photons and neutrino?
- 11
0
votes
2
answers
958
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About conversion of neutrinos to photons
Photons have the ability to convert into electron and electron have the ability to convert into photons. Can this property be found among neutrinos? Is there any method to convert neutrinos into ...
- 99
15
votes
3
answers
5k
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Why do Neutrinos pass through us but photons can't pass through us? [duplicate]
Neutrinos have no mass and no charge. Therefore, they are not deflected by the other particles in our body and pass through us. Photons too have no mass and no charge, but why are they being deflected ...
- 377
-2
votes
1
answer
386
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Do we have any evidence of slower-than-light neutrinos? [duplicate]
I'm writing a piece on the electron neutrino. There's plenty of excellent material out there, but I'm struggling to find anything definitive about their speed. There is for example evidence from ...
- 11.3k
8
votes
4
answers
6k
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How do neutrinos pass through the sun so quickly?
If it takes thousands of years for light to escape our sun then how can neutrinos generated in the very center of the sun reach earth in just 8 minutes? Why is their speed so great that they can ...
- 835
0
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1
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127
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What is the bigger number of particles crossing an area: the number of photons or the number of neutrinos? [closed]
Take an squared area with (10²)² m² in front of the sun. What is the bigger number of particles crossing an area: the number of photons or the number of neutrinos?
Just for clarification: you can ...
- 407
18
votes
3
answers
4k
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Why are neutrinos more weakly interacting than light?
When people describe neutrino interactions they describe them as rare/infrequent due to the fact that the neutrinos are electrically neutral and have little mass, if any. Well why then is the photon ...
- 191
6
votes
3
answers
6k
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Which is the lightest thing in this universe? Is that a photon or neutrino?
I hear a lot of people saying that neutrino is the lightest subatomic particle but according to me a photon must be the lightest as nothing can travel faster than light because it gets heavier and ...
8
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3
answers
1k
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If a neutrino has a rest frame, why can't a photon have a rest frame as well?
Concerning Rest Frame Wikipedia states:
For example, in the rest frame of a neutrino particle travelling from the Crab Nebula supernova to Earth the supernova occurred in the 11th Century AD only ...
- 221
56
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2
answers
6k
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Neutrinos vs. Photons: Who wins the race across the galaxy?
Inspired by the wording of this answer, a thought occurred to me. If a photon and a neutrino were to race along a significant stretch of our actual galaxy, which would win the race?
Now, neutrinos ...
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