system
Given the following post, respond as if you're commenting on Reddit:
human
Do particles, like neutrinos affect anything, if they somehow stopped existing, would it have a noticeable effect on us and what we can observe around us?

I'm assuming, there are other kinds of particles, that don't interact electromagnetically. Please correct me, if that assumption is wrong.
gpt
Neutrinos don't interact electromagnetically, it's true. If the Sun somehow stopped emitting neutrinos (most neutrinos on Earth are streaming out from the Sun), it wouldn't affect us too much.

It would probably affect the Sun, though. Neutrinos carry a lot of energy away from the Sun (just by virtue of how fast they're travelling), so that would need to change. What would happen depends on how you're getting rid of neutrinos.

Neutrinos are important to a lot of nuclear processes. They are needed to balance the equations. Just like energy and electric charge, there's a conserved quantity in nuclear reactions called the *lepton number*. It's the number of leptons minus the number of antileptons.

There are six kinds of leptons: electrons, muons, tau particles, and the three flavours of neutrino. If you create one during some reaction or other, you have to create an an antilepton as well (not necessarily the antiparticle for the same lepton). For example, when the Sun fuses two protons into a deuterium nucleus, one of them turns into a neutron. To conserve charge, this creates a positron. To conserve lepton number, this in turn creates a neutrino.

The same thing happens with a lot of radioactive processes: beta decay in particular. That's when a radioactive nucleus converts one of its protons to a neutron, or a neutron to a proton. In the first case, it emits a positron and a neutrino; in the second case, it emits an electron and an antineutrino. If the nucleus were somehow unable to produce a neutrino, it would not be able to decay in that way (if it can decay by breaking into two nuclei, that would still be possible).