Leo: As I say, I go with whatever view appears to be the most useful. So I have no objection to you thinking of an atom as "changing itself at speed c whilst retaining almost the same external properties" if there is some way in which that point of view is useful for describing and predicting observed reality. But I think, on other threads, we've established that we still disagree as to the question of the universe, as you've put it, "being made to conform to observation".
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But I think we probably both agree that it is the identification of invariants which is at the heart of discovering the patterns of nature, because invariance is the defining feature of patterns. On an intuitive level, it seems easiest to do this with material objects, or things that we regard as being the constituents of material objects (like atoms). The principle of "conservation of matter" is one that we have experienced every day for our entire lives. I can still remember watching my young children learning it.
But I brought up conservation of energy because I think it's useful to consider situations in which the entity being conserved is
not so obviously visible. In fact, I thought it interesting enough to start a thread on the subject a while ago called "What Is Energy?":
onlinephilosophyclub.com/forums/viewtop ... mp;t=10252
Kinetic and gravitational potential energy are accessible because we all learn about them in high school physics. But energy is still an interestingly nebulous concept. If I see a rock sitting on a hill, and then I see that same rock rolling down into the valley, then it's natural, and seems obvious, to think of the two events as featuring the same rock. But it's not so obvious that there is something which in the former situation is associated with the rock's spatial location and in the latter situation is associated with its velocity which is
also the same thing in the two situations. In this case, the only indication that we have of some "thing" being conserved is that two different equations yield the same result.
It was by using this example, in the "What Is Energy?" topic, that I had hoped to explore, from a simple high-school physics point of view, the topic of these kinds of conserved quantities and to examine whether it is useful to think of
any of them as more than the results of mathematical book-keeping.