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Comment by 8bitsrule | Hacker News Reader

" in February 2023, [KM3NeT] detected the most energetic neutrino ever observed. It's called KM3-230213A, and its estimated energy was 220 PeV (220 x 10^15 electron volts or 220 million billion electron volts) "

- https://phys.org/news/2026-04-energetic-neutrino-primordial....

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That's an insane amount of energy. If your are knowledgeable about this do you know why some neutrinos have more energy than others? surely it is just a relationship with it's speed. I thought all neutrinos moved close to the speed of light.

If my quick math is correct that is equivalent to dropping 3.59g one meter in a vacuum in earths gravity. insane that a subatomic particle can have that much energy.

Particle physics processes in the sources we suspect accelerate particles in a way that results in a power law distribution of energies. So you can get extremely high energy particles, but the higher the energy the rarer.

And sources have a maximum energy they can accelerate particles to.

https://en.wikipedia.org/wiki/Fermi_acceleration

Neutrinos interact only to the weak interaction and (IF they have rest mass) to gravity. (They have no charge.)

This article has some ideas on such an energy:

https://phys.org/news/2025-05-physicists-route-neutrinos.htm...

It says "typically, energetic neutrinos from active galactic centers are thought to originate from interactions between protons and photons, producing gamma rays of comparable intensity." and suggests other theorized sources.

Another good source on this new branch of astronomy:

https://arxiv.org/html/1501.07798v1

Newer idea (May 2026): blazars

https://www.sciencedaily.com/releases/2026/05/260523103912.h...

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