How fast do neutrinos actually go?

  • Thread starter fbsthreads
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In summary, Neutrinos can travel at any speed up to the speed of light, depending on their energy. While the standard model predicts that neutrinos have no mass and therefore travel at the speed of light, observational evidence suggests that they do have a nonzero mass and can travel at speeds slightly less than the speed of light. Additionally, their flavor can change as they travel, which is evidence of their nonzero mass.
  • #1
fbsthreads
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i wanted to find out what percent of C neutrinos travel at.

so i got on the web and found pages quoting 'light speed' and 'almost light speed'.

my understanding was that they travel slower than light becuase they change flavour as they travel, (they couldn't change if going at light speed).

so how fast do they travel through space?
 
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  • #2
I depends on their energy. If they are actually massive (as seems to be the case), it should be possible to find neutrinos at any speed (up to c).
 
  • #3
Yes, *I think* inorder for there to be uncertainty in the flavour there must be unceratnity in the mass, so the mass must be non-zero. Therefore they can travel at any speed lower than c.

Of course in the standard model neutrinos don't have mass and therefore travel at c (which is why some siters say they travel at c), but as far as I'm aware observational evidence overwhelmingly suggest that neutrinos do have a non-zero mass.
 
  • #4
Neutrinos from nuclear reactions have energies on the order of 1 MeV. Their mass if nonzero is thought to be around .1 eV. This means
[tex]\gamma=10^7[/tex]
But
[tex]\gamma={1\over\sqrt{1-\beta^2}[/tex]
so [itex]\beta[/itex] which is the ratio of speed to speed of light, is veryvery close to 1:
[tex]1-\beta\sim 10^{-14}[/tex]
 

1. What is the speed of neutrinos?

The speed of neutrinos is incredibly close to the speed of light, which is 299,792,458 meters per second. However, studies have shown that they may have a very small mass, which could cause them to travel slightly slower than the speed of light.

2. Can neutrinos travel faster than the speed of light?

No, according to Einstein's theory of relativity, nothing can travel faster than the speed of light. However, there have been some experiments that have suggested neutrinos may have exceeded the speed of light, but these results have been disproven.

3. How do scientists measure the speed of neutrinos?

Scientists use a variety of methods to measure the speed of neutrinos. One method is to measure the time it takes for neutrinos to travel a known distance, such as from the sun to Earth. Another method is to measure the energy and mass of neutrinos and use Einstein's equation, E=mc^2, to calculate their speed.

4. Do all neutrinos travel at the same speed?

No, not all neutrinos travel at the same speed. Neutrinos come in three different types, or flavors: electron, muon, and tau. Each flavor has a different mass, which could affect their speed. However, the differences in speed among the three flavors are extremely small and difficult to measure.

5. Why is it important to know the speed of neutrinos?

Knowing the speed of neutrinos is important for several reasons. It can help scientists better understand the fundamental properties of neutrinos, such as their mass and behavior. It can also help in the study of particle physics and the origins of the universe. Additionally, knowing the speed of neutrinos is essential for accurately predicting and interpreting data from experiments involving these elusive particles.

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