I’m current reading Project Hail Mary, written by Andy Weir, who also wrote The Martian, which was made into a movie I enjoyed quite a bit. Like The Martian, real science is at the heart of Project Hail Mary–specifically, science used to solve problems the protagonist must solve. Overall, I’m enjoying the book, but there are moments when I don’t understand the science or scientific terms. One example of this involved neutrinos.
To gain a better understanding of neutrinos, I just watched a NOVA episode (“Unknown Particles”) on it, as well as Standard Model in general. I’m going to use thread to write some thoughts, “thinking out loud” as it were. Oh, I also watched this TED-Ed video clip that was helpful. (Hopefully, TED Ed is a reliable resource; for what it’s worth, It seems consistent with what I learned in the NOVA episode.)
One thought on “Neutrinos and Other Matters Involving Particle Physics”
The idea that scientists will suggest the existence of some physical entity or force in order to explain unexplainable discrepancies in mathematical calculations or scientific theories is not new to me, but I was still taken aback by the way and extent to which scientists did this with neutrinos.
Here’s my understanding of the way scientists “discovered” neutrinos. Sometimes a part of an atom’s nucleus will change into an electron. (Edit: The nucleus seems to have too much energy and spits out an electron. The process is known as beta decay.) But when the scientists do calculations for this, energy is missing. Based on the law of the conservation of energy, this is a huge problem. To solve it, one scientist (Fermi?) suggested there is another particle containing the missing energy. That particle is a neutrino. This particle has no mass, and as at the time, there was no way to detect it. Indeed, I believe scientists believed it would be virtually impossible to detect–which makes neutrinos seem like a very unscientific concept.
However, later scientists did construct a way to detect it–or at least they found evidence they would expect if neutrinos existed. (I need to go back and watch this section because I’m not clear on the this part.)
Actually, this is not entirely correct. One scientist found some evidence, but the amount of neutrinos(?) that should have appeared did not. I think two-thirds of the neutrinos were missing.
Once again, to explain this discrepancy, another scientist suggested the possibility that there are different types of neutrinos. (We’re looking for one type and missing the other two?) I think part of this new idea involved the idea that neutrinos would oscillate between the three types.
The problem with this was that neutrinos had no mass and moved at the speed of light. (Edit: According to the episode, objects with no mass must move at the speed of light. Unfortunately, I don’t know why that is.) Based on the Theory of Relativity, time stands still for an object moving at the speed of light. If neutrinos are not experiencing time, they can’t change–i.e., they can’t oscillate between different types of neutrinos. (Actually, the issue also involved not having any mass. Later, they concluded that neutrinos must have a tiny bit of mass.)
OK, I feel like my explanations above are not 100% accurate, so I want to stop here. Let me just make one main point that I wanted to originally make: To me, there is something hokey about the concept of neutrinos. To be fair, much of this involves theorizing, but it also doesn’t seem so far away from using ghosts or God as an explanation of some physical phenomenon.
Also, I didn’t realize that the Standard Model only explains a small fraction of the matter in the universe. The vast majority of matter is unknown (“dark matter”).