This thread got me looking at Neutrinos for the very first time. They

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Discussion Overview

The discussion focuses on neutrinos, their properties, and their interactions with matter. Participants explore the historical context of neutrino discovery, their role in beta decay, and their implications for mass and energy in stars. The conversation includes theoretical considerations and the nature of neutrinos as fundamental particles.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that neutrinos were first postulated by Wolfgang Pauli in 1930 to account for conservation laws in beta decay.
  • Another participant argues that neutrinos constitute "normal matter" and that weak interactions must conserve charge and lepton number.
  • A different viewpoint suggests that mass and energy in stars are continually converted into neutrinos, which do not interact significantly with baryonic matter.
  • Another participant counters that while neutrinos are weakly interacting, they can still interact with baryonic matter and contribute to the universe's stress-energy.
  • A participant questions whether neutrinos can be reversed back into baryonic matter, drawing a parallel to electromagnetic radiation.

Areas of Agreement / Disagreement

Participants express differing views on the nature of neutrinos, their interactions with matter, and the implications of their existence. There is no consensus on whether neutrinos can be converted back into baryonic matter.

Contextual Notes

Some statements rely on specific definitions of "normal matter" and the nature of interactions, which may not be universally agreed upon. The discussion includes assumptions about the irreversibility of neutrino conversion and the role of weak interactions.

Tanelorn
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This thread got me looking at Neutrinos for the very first time. They are the most recently discovered fundermental particles, the Tau Neutrino was first observed only 11 years ago in 2000.


The neutrino was first postulated in 1930 by Wolfgang Pauli to preserve the conservation of energy, conservation of momentum, and conservation of angular momentum (spin) in beta decay. This was done by adding an undetected particle that Pauli termed a "neutron" to the proton and electron already known to be products of beta decay:

n0 → p+ + e− + νe

He theorized that an undetected particle was carrying away the observed difference between the energy, momentum, and angular momentum of the initial and final particles.
The electron neutrino is said to be associated with the electron because in the above beta decay they are produced together.



Since Neutrinos interact very weakly with ordinary matter it appears that matter is being continually converted all the time through beta decay into something which no longer interacts with matter.
 
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Tanelorn said:
Since Neutrinos interact very weakly with ordinary matter it appears that matter is being continually converted all the time into something which no longer interacts with matter.
Neutrinos still very much constitute "normal matter". And there isn't an out-of-equilibrium conversion of all non-neutrino matter to neutrino matter: weak interactions must conserve charge as well as lepton number.
 


bapowel yes I mispoke, Neutinos are still normal matter.

My point was, if I understand the subject correctly, that Mass and Energy in stars seems to be continually being converted into neutrinos, particles which radiate thoughout the universe and no longer interact or play any significant role with baryonic matter. i.e. the mass and energy is permanently lost.
 


Tanelorn said:
no longer interact or play any further role with baryonic matter.
...until they hit a detector at SuperK. It's true that neutrinos are very weakly interacting, but they do still mix and mingle with baryonic matter on occasion. Also, they contribute to the stress-energy of the universe and so they gravitate.
 


OK I assume then that the process cannot ever be reversed and neutrinos reassembled back into useful baryonic matter again? I guess that EM radiation is also similar in this regard.
 

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