Right on the mark!!!... with 3 questions that expose the degree to which Science unjustifiably promotes Fact-less abstraction.
IF Fact does not precede abstraction, THEN dogma proliferates.
Given recent technologically enhanced capacity to resolve differentials that facilitate more precise measurements... e.g. the James Webb sky scope/receiver, and the CERN upgrade... it has become increasingly difficult to deny the existence of observable dynamic processes that are indicative of non-measurable substance and structure.
To investigate the bottom line fundamental Fact underlying the motion of the universe requires a unbroken kinematic logic chain, from the measured motion event to the fundamental momentum mechanism.
Such is highly unlikely in a perturbative analysis environment.
However, if one constructs a non-perturbative virtual/digital CAD SIM visual emergence analysis environment... i.e. a conceptual kinematic chain tool... that facilitates visual objectification of a fundamental momentum mechanism, substance, and distribution structure, one can give universal dynamics a basis in Fact.
The derived terms of abstraction... e.g. space, energy, entity, existence etc... would only apply within the specified logic framework, but IF Fact exist prior to abstraction, THEN knowledge can be directly derived from the expression of Fact, AND IF the logic framework and its substance emergence distribution mechanix are consistent with reality, THEN application of derived knowledge to reality, will yield accomplishment.
Although my 2023FQXi Essay: "Digital Science: Emergence of Quantum Consciousness" (http://uqsmatrixmechanix.com/2023FQXiEssay4pdfconv.php) was intended as a demonstration of how a non-perturbative analysis framework would change science, the demonstration utilized a single point pulse sourced emission of spatially defined minimum/indivisible quanta of Energy (QE), which inherently resolves all forces as derived of a single force, and consequently FQXi rejected my essay as being an "alternative ""theory of everything"", not an essay about how science could be different."
In that the 2023 FQXi competition implementation of alias submission, does not facilitate exchange of participant essays to be utilized as background for discussion in comments, one's ability to enhance the level of the discussion without excessive reiteration is constrained, and FQXi's rejection Of my essay was perhaps serendipitous... i.e. I can herein provide a link to the rejected essay: "Digital Science: Emergence of Quantum Consciousness" (http://uqsmatrixmechanix.com/2023FQXiEssay4pdfconv.php) ... and the therein proposed logic framework can be utilized to investigate your 3 questions, without danger of proliferating dogma.
“Why is the universe moving?”
Resolve of the underlying mechanix of the numeric differentials requires a mechanical description of emergence fundamentals... i.e. a momentum mechanism, substance, and distribution structure... and the logic component function of each as an operative of the emergence process.
IF given a single source pulsed emission of substance, as a momentum mechanism, a visually objectified minimum/indivisible unit of spatially defined Energy (QE) as substance, and a QE distribution structure quantized by a minimum/indivisible unit of Space (QI), THEN are there observational properties of motion that could not be abstracted from the proposed logic framework and associated emergence mechanix?
Utilizing the proposed logic framework and emergence mechanix associated with a single sourced pulsed emission, QE spin as a consequence of momentum mechanism dynamics, is inherent in Space-Time Energy emergence.
Application of QE scale spin to observable reality, resolves a potential kinematic logic trace, from the fundamental momentum mechanism, with which to derive the QE choreographies of unobservable entities, which underlay observable motion of indeterminate causality.
To examine "the essential differences between what can actually exist, and what can only exist in individual subjective human minds and imaginations" requires a definition of "exist".
IF physical implies substance occupancy of space, AND space is objectified as the logic structure in which substance dynamics are choreographed by a pulse sourced momentum mechanism, which Spontaneously Harmoniously Resolves (SHR) substance distribution throughout the entire universe, THEN do all manifestations of substance, either as a minimum/indivisible quantum of Energy (QE), or composites thereof, "exist" as physical entities?
Utilizing the proposed logic framework and emergence mechanix associated with a single sourced pulsed emission, a consciousness hierarchy is differentiated, which can be abstracted to imply QE composites that have SOUrceLink (SOUL) access, and other QE composites that do not.
Application of differentiated consciousness hierarchy to reality, resolves a potential uniqueness between humans as digital circuits... i.e. QE composites... manifest by emergence mechanix, and AI as digital circuits... i.e. QE composites... configured by humans from QE composites, manifest by emergence mechanix, that do not have a SOUrceLink.
“Can everything that exists be measured?”
IF the unit of measurement is a minimum/indivisible unit of space (QI), and QE as the minimum/indivisible units of substance, can occupy QI... i.e. QE are spatially defined quanta of potential momentum... does information contained within a QI... e.g. spin direction and quantity of its QE occupants... on a given pulse of the fundamental momentum mechanism "exist" as a measurable physical entity?
Utilizing the proposed logic framework and emergence mechanix associated with a single sourced pulsed emission, a networked intelligence emerges, which can be abstracted to imply a SOURceLinked entities responsibility for monitor and resolve of the "I Am" body as substance, mind as structure, in accord with the Spontaneous Harmonious Resolve (SHR) of QE distribution throughout the entire universe in which we are all embedded.
Acknowledgment of the individual human's function as monitor and resolve of "I Am" body as substance, mind as structure, has application to self healing, and social stability,
In that my essay was rejected, I am unable to vote your essay the 10 rating it deserves, but thank you for your well justified recognition "that non-measurable aspects of the world do in fact exist", and that the views that Science promotes "have implications for how human beings see themselves and the world they live in, including philosophical ideas of ""free will""... i.e. Science's denial of "non-measurable aspects" absolves the individual human being from taking responsibility for the consequences of one's actions.