![](https://keishinrei.code.blog/wp-content/uploads/2024/05/251.png?w=614)
Even though they interact very rarely with matter, neutrinos are absolutely everywhere — after photons, they’re the second most abundant particle we know of in the Universe, with trillions passing through your body every second. They don’t really have a size, because they are quantum mechanical particles, which means they follow their own weird rules. As “leptons”, neutrinos are cousins of the electron, but they carry no electric charge.