Wannabe sciencefag here, could anyone explain why proving that neutrinos can change from one type to another prove that they got mass?
>Wannabe sciencefag here,
ok
>>7712356
>could anyone explain why proving that neutrinos can change from one type to another prove that they got mass?
Start small, lil' nigga. A reasonable answer to this question requires a lot of in depth knowledge of quantum mechanics and particle physics.
>>7712372
>Start small, lil' nigga
How small, Bubba?
>>7712372
>requires a lot of in depåchef knowledge in quantum mechanics and particle physics
Yeah i got that. Please explain.
>>7712380
In depth*
Autocorrect
>>7712356
Light moves at c
In a photons reference frame, time stops. How can an object for which time isn't passing change at all?
All objects that move at c are massless, and only objects with mass can move slower than c.
If an object can change types, than time is passing for it, and therefore it is not moving at c, therefore it has mass.
>>7712386
Omg thank you! That makes sense.
>>7712386
but photons have mass relativistically
>>7712386
Photons do not have a rest frame. You cannot apply the notion of time and space from timelike intervals to lightlike ones.
>>7712411
Not rest mass.
"Relativistic Mass" and energy are the same thing
>>7712386
Not OP but that's exceedingly intuitive. Thanks.
how does this apply to current?
Electrical current flows at the speed of light (at least think it does), but electrons have mass.
>>7712706
>Electrical current flows at the speed of light (at least think it does)
It doesn't, electrical current flows at a speed relative to the number of collisions an electron will have in a medium, similar to sound (and light in a medium).
Electrical current is based on a difference in potential, the difference causes electrons to accelerate, the electrons accelerate until they hit something else (other free electrons), and transfer kinetic energy.
>>7712722
thank you
>>7712706
Imagine a hundred people in a queue. They're all packed directly behind each other.
If you push the guy at the back, then he'll push into the next, and he into the next, through the queue far more quickly than anyone actually moves forwards.
The individuals are the electrons and the push is the current in case it wasn't clear. So it's not that the particles are individually moving very quickly (that's a different concept, drift velocity), it's just that the flow is rapid.
>>7712356
http://su3su2u1.tumblr.com/post/130896290963/pendulums-springs-neutrinos-and-nobels
This explains it pretty well.
Incidentally, the same idea of "coupling between different particle states creates mass states" is the whole deal behind how the Higgs field causes particles to have mass. The Higgsless standard model has a rather different collection of particles; their interaction with the Higgs field allows them to couple together into new, massive particles. See here for more: http://profmattstrassler.com/articles-and-posts/particle-physics-basics/the-known-apparently-elementary-particles/the-known-particles-if-the-higgs-field-were-zero/
Does neutrino oscillation imply lepton family number is not conserved?
If so, why does my particle prof say it is conserved? Because babby's first particle physics course?
>>7713844
>Does neutrino oscillation imply lepton family number is not conserved?
yes
>If so, why does my particle prof say it is conserved? Because babby's first particle physics course?
in the standard model neutrinos are mass less, so it is conserved. I doubt you will be doing beyond standard model in undergrad
>>7713886
Okay, that makes sense, thank you.
But why isnt it part of the standard model?
>>7713889
Because we only got a working model of neutrino masses 3 years ago
