BTW, morri, we also still don't have a real definition of what exactly mass is. Sure, we know that a redwood tree has a lot of mass, but why? What part of the world makes mass, and what makes that part? The theory right now lies upon the shoulders of one Higg's Boson, proposed to be one of the "Standard Model*" particles. (one of the two that haven't been seen yet) It would help explain why elemantary particles which should not have mass in fact do. It works as a field (since every particle has a field and vice versa) which permiates through all of the universe and it has a non-zero vacuum expectation value which is what makes it work. It acts sorta like a pool of molasses that "sticks" to the otherwise massless fundamental particles which travel through the field, giving gauge bosons** mass! If we could actually find a Higgs boson, we could use it to discover why certain things would act that way. PLUS, after doing some research of my own, it looks like the neutrino's you mention are practically massless and move close to the speed of light. Comparing that going through an object to the normal things we look at (say a proton or neutron) would be like showing the difference between shooting a paper with a 12 guage shotgun and a peeshooter. Also, the standard model assumes neutrino's ARE massless and although the standard model insn't always a scientists best friend, it has been proven correct with the discoveries of the W and Z bosons. Then again, there are a few expiriments claiming that neutrino's may have mass but now I'm just walking in circles. Also, I will admit that the model isn't a complete theory of everything since it only describes the three forces that make up what we see but not the force of gravity.
*the Standard Model is what scientists are trying to use to explain everything, although the model falls short (doesn't even attempt to explain gravity) and the equation itself is absolutely massive, requiring a minimum of 18 numerical constants and violates the unwritten law of the simpler the better, like Einsteins e=mc^2 equation
**gauge bosons are the bosons/particals that carry the fundumental forces of nature.
If you read all of that, than thanks for caring.
If you understood all that, congratulations are in order.








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