> My claim is "electron charge could possibly vary, or not, but all existing evidence suggests it does not, and no existing evidence suggests it does". But you

> My claim is "electron charge could possibly vary, or not, but all existing evidence suggests it does not, and no existing evidence suggests it does". But your claim is a falsehood. I asked you to provide evidence that it doesn't vary and you said you can't but you assume the variance comes solely from the measurement equipment. That's not what "evidence" means. We have variance. Either there's proof that it's the measurement, or there isn't. Assuming is just that. I'll tell you another assumption we often take for granted: speed of light. Actually we don't know if the speed of light is as measured, C. Do you know why? We can only measure reflected light. So we measure it going to some place, and then get reflected back. Maybe it goes there at C/2, and then comes back instantly. OR maybe it goes there instantly, and comes back at C/2. Or even more likely, it goes there at some ratio of C, and comes back at the inverse ratio of C. We can't know that. In fact Einstein explicitly mentions this in his work, and calls C, the "average speed" just that - a convention. Either you can prove it, or you can't. But how many people you hear, including scientists, talk about the speed of light this way? Not many. We take the model for granted to preserve our sanity. But from time to time we also need to remember: it's just a model. > I'm referring to elementary particles, of which protons and neutrons are not (but quarks are). Protons and neutrons are not. But until relatively recently, they were. What are we going to find out tomorrow? I actually Googled this to see how elementary particles are defined, and very first thing you see is this sentence (emphasis mine): "Particles CURRENTLY THOUGHT to be elementary..." See, when they need to be specific, they're quite aware this is just the current assumption. Nothing else. You know, the only place it pays to be so sure about current models being objectively right and the law is school. In school you can propagate this myth as if you have the gospel in your hands. In the lab, this same PoV is frowned upon. "What if" is king. As long as it doesn't contradict existing evidence.