- Edited
KhakiHeron
I believe we can find a mechanism to represent complex values as single values - and I agree it likely is related to vectors. The example you give, however, remains with real values (x,y) and not a single value z - which could be thought of as the scalar value of the vector (which cannot end up as x+iy, as this is two real values and not a single complex value).
AquamarineJellyfish & CornflowerCicada
Whole numbers are abstractions - what is common to all single objects, what is common to all pairs of objects. Much of mathematics uses abstractions - what is common to all algebraic equations of the second order. Geometry can be more or less the same - what is common to all line segments, what is common to all squares, to all triangles. The geometry, arithmetic, and equations of math are statements about any object or concept that fits the abstraction. The equation of a pendulum is very similar to that of a vibrating string, or of a wave. The equation is about any abstraction of the concepts - which is why the pendulum equation can be applied to the pendulum, the vibrating string and a wave. Each physical system can be abstracted so that it fits the equation (maybe with some additional values or constants). The fact that the equations need to be tweaked to fit the reality is because no physical event exactly matches the abstraction.
The power of mathematics comes from this ability to abstract - and the equations can apply exactly to the abstracted situation. When applied to physical events, we can take an event and find that it is like the abstracted situation. As with the pendulum, string, and wave, we can find multiple events that abstract to the same (basic) equation. There are always differences between the physical event and the abstracted situation - always (we never get the exact values for every event that is represented by an equation). So mathematics is good at abstracted situations, it is only good to some degree of error when applied to a physical event.
Then there is the consideration of the symbols used for values, for the equations - for being able to communicate an abstract concept between people. This includes the numeric representational system (e.g., Roman numerals, ratios, positional real numbers, powers, logs), infinitesimal symbols (e.g., dx/dy, Newton's symbols, epsilon-delta), vectors, or matrices - and other mathematical symbols. These can vary significantly between societies, cultures, aliens - as they are devised creations not inherent to some deterministic appearance. Mathematics cannot progress without these symbols - and mathematics has been prevented from advancing without the introduction of new devised symbols. Our calculus would be more difficult using Newton's symbols than Leibniz'. We could not have the technology we have using just Roman numerals or just fractions.
Science and mathematics are very co-dependent, although there are few abstract situations (aside from simple arithmetic e.g., 1apple+1apple=2apples) that exactly always matches physical events. And the inexactness, or error terms, leave wiggle room for interpretation of which equations (or tweaks) fit the experimental results.
Science has a number of historic paths that have not taken us down the always 'correct' (in hindsight) path. So I do not see science as deterministic (nor do I see mathematics as such - for symbolic reasons).