A lot here, and interesting stuff. First you started off with a form of the ever popular Simulation Theory:
Simulation hypothesis - Wikipedia
Which I'll return to at the end below.
And which you used to illustrate a broad concept.
You also along the way in your post brought in another, different topic that is also so interesting, about our world and what we might know of it (which really is an independent topic in itself). Let me address
that here first. Because there is a useful thing to bring out on it.
Creating a methodology to measure what we perceive doesn't mean we are also revealing the fundamental nature of reality. It just means we are describing something we see. ...3rd topic: There could be some other aspect to reality beyond the physical stuff we see and measure.
First, I agree with the
last sentence in this quote. That's a truly interesting thing to think on, and I like to discuss that at times (I've a few times). I'll call that the '3rd topic' (maybe the most interesting one).
But here, in this response, I want to at first address just the 2nd topic alone
(so, not the 1rst, nor the 3rd yet -- they deserve their discussion imo).
So, this next is about a valuable insight regarding this topic:
"Creating a methodology to measure what we perceive doesn't mean we are also revealing the fundamental nature of reality. It just means we are describing something we see."
Initially, I'd have
not had any reason myself to expect that our 'methodology' (as you termed) -- or what I call our
'physics' -- which we have developed over time would be anything more than
just a construct. Like an arbitrary building even. A model that
sometimes acts like the real world, if you simplify the real world a lot....
Arbitrary and not corresponding perfectly to any actual reality out there.
More like a...model of car. In which case,
we could have built a different model (like a different car brand or model), and have had about equal results:
some practical functionality.
...except...I've learned there is a decisive reason to
not think that.
Instead, to my delight and wonder, I've found out we are gradually discovering pieces of the real genuine external reality (!) --
the real physics, the
actual and real structure of Nature -- the absolute thing that has a definite final form, and so we have some pieces of the actual structural design we now have pinned down, pieces that won't be modified, being perfect (!), but instead can only be incorporated into the more full picture,
if we manage to find more of that real picture
-- we are finding the real thing out there, slowly, in pieces, often with only partial bits that are incomplete.
We are far from having the fuller picture at this point though.
Here's why I think so:
Occasionally in physics a new theory predicts an entirely new thing never before thought of, nor seen or previously suspected even, a striking and surprising new prediction of a truly new to us thing we don't see, haven't seen, didn't have a hint about existing...
And...
sometimes (now and then among the many new theories, one of them...), when we finally find a way to observe some decisive aspect of that new prediction from that new theory -- in the effort to shoot down the theory basically, testing in order to find out
whether or not the theory was correct in that novel new prediction of a never observed thing...
We sometimes find, in a dramatic confirmation moment that takes our breath away, one of the novel new predictions is
correct. (e.g. Einstein's General Relativity for example predicted surprisingly the novel prediction that light would be bent twice as much by gravity than had been imagined before by classical physics, while light being bent by gravity was itself a never before observed thing additionally, and only a hypothetical idea itself. The new theory said the old hypothesis was wrong, and made this novel new prediction. Which years later was confirmed to the surprise and delight of very many physicists).
So, what happens: some of our new physics theories turn out right in predicting truly novel to us new things we had never imagined or seen. Often intricate and deeply hidden from ordinary observation of the human eye, requiring powerful magnifying or amplifying or concentrating equipment to even allow an observation to be possible.
That kind of success isn't what a mere arbitrary construct/model that is
somewhat like the world would be able to predict.
Instead, we get these surprising novel predictions and then must devise a way to even observe some aspect of that prediction.
So, we have some actual discoveries of parts -- bits -- of the structure of an actual, real physics, that already exists, independently of us.
And we have a glimpse of a part of the structure, from an angle, in odd lighting, and can't figure out more quickly, but have to keep guessing new ideas what the rest of the unknown structure, and new things to try to find, never before thought of or imagined in any way.
None of this was about the Simulation Hypothesis of the Universe, which is just to me a fun thing to imagine, but...(now changing topic here to
that topic)...it's interesting to notice that a real physics that is basically a consistent structure that is mathematically describable (in principle, though we are far from having found it all)...well, what's the difference between that and a 'computer simulation' -- they are very much the same. Both are just mathematically operating systems.