>>3449723>Why does it being matter automatically mean we can observe it, is what I'm askingBecause we can only "observe" things by striking the some form of electromagnetic phenomena off of something that responds to electromagnetic phenomena. Typically we bounce photons off of things and they return information to our eyes or to our sensors. If the thing does not give a shit about the electromagnetic force, the light doesn't come back.
Mass spectrometers work on the principle that every element leaves a different "dent" in the energy of a given photon. So when you strike a photon against something you check the energy of the returning photon and you can tell with 100% consistency exactly what it was you shined the light on.
Here is a brief example of what those dents look like.