Science is obsessed by the concepts of observation and measurement, but these are both essentially psychological phenomena. It should be fairly obvious that consciousness plays an important role in the unfolding of the cosmos.

Relativity tells us the nature of the observation is a function of the temporal/spatial relationship between the observer and the observed. Quantum theory tells us the very act of observation determines which values can be observed and what the possible measurements can be. Thermodynamic concepts like Entropy are all about the amount and nature of disorder, certainly a question of perception and subjective definition.

Our means of reasoning about reality are restricted to a brain which evolved with no need to properly perceive or conceive of reality, except to allow an organism of the order of 1 meter/1 second spatio/temporal dimension to operate--most of the time. I.e., in order for us to have the perceptual equipment necessary to survive long enough to reproduce we simply do not need to understand the entire universe, just our little piece of it. Our brains evolved sufficient complexity for us to survive and prosper in our ecological environment, plus a bit more for safety purposes. We just don't need any more.

We've developed ingenious mechanical (sensors and computers) and conceptual (language and mathematics) devices to help extend our understanding of the unknowable, but they will always be inadequate to complete our knowledge. Any philosophical theory or AI capable of successfully modelling reality will be unable to communicate its findings to our brains.