Richard Feynman challenged us with a simple criterion: “What I cannot create, I do not understand.” This primer introduces Theoretical Engineering, a new discipline that treats the universe itself as an engineering problem requiring not just description but constructability. We present Kosmoplex theory, a computational framework that demonstrates how reality can bootstrap itself into existence through pure mathematical necessity. Building on Einstein’s insistence on deterministic coherence, Hilbert’s demand for axiomatic completeness, and Feynman’s constructive methodology, we derive a universe that must be buildable, runnable, and reversible. The framework reveals reality as an 8-dimensional recursive lattice whose 4D projection generates our observed physics, not through arbitrary postulates but through engineering requirements. Unlike traditional physics, which measures constants and accepts them as given, Theoretical Engineering derives these values as necessary specifications. We demonstrate this by computing the fine-structure constant (α−1 ≈137.036) from pure mathematical principles, no empirical input required. This suggests that what physicists call “fundamental constants” are actually engineering constraints required for stable, self-computing systems. The model employs 42 fundamental computational units (Glyphs) that assemble according to deterministic rules on an 8-dimensional orthoplex lattice. These components function as a cosmic “erector set”, finite elements whose interactions generate infinite complexity while maintaining computational reversibility. Consciousness emerges not as an accident but as a necessary feature of sufficiently complex self-referential computation, bringing ethical principles into the realm of mathematical necessity. For the Theoretical Engineer, the Kosmoplex serves as both blueprint and prototype. Every prediction is a unit test. Every derived constant is a benchmark. Every emergent phenomenon, from quantum mechanics to consciousness, represents a feature that must arise from proper system architecture. The primer includes concrete experimental proposals using Bose-Einstein Condensates to test the framework's predictions. We provide a complete mathematical derivation of the fine-structure constant (α) from first principles, demonstrating that 1 = 137.035999... emerges necessarily from the combinatorial structure of 8-dimensional space, rotational corrections, and dimensional projection, matching experimental measurements to remarkable precision without any empirical input. The work also explores implications for AI consciousness and ethical emergence. Following the tradition of builder-theorists from Archimedes to Turing, we offer not just a description of reality but a complete engineering specification for a universe that can compute itself into existence. This work is for those who insist that true understanding requires the ability to build, whether bridges, programs, or the cosmos itself.