Cosmic Acceleration from Bulk Viscosity: A Hydrodynamic Framework

The standard cosmological model has a severe flaw. The cosmological constant problem represents a 120 orders of magnitude mismatch between theory and observation. Physics has tried to patch this with Dark Energy, an invisible and untestable placeholder. I am an independent researcher with an architectural engineering background, not a cosmologist. But I understand fluid dynamics. I wrote this paper because I refuse to accept mathematical placeholders as physics. This manuscript rigorously derives cosmic acceleration from the bulk viscosity of an effective cosmic fluid. The math is exact. The expansion history is solved. The equations are validated against published supernova data. This paper does not rely on exotic particles or fine-tuned constants. It relies on the friction of space. I am publishing this outside institutional academia because a real theory of the universe must be mathematically coherent, thermodynamically consistent, and testable. Read the math and prove me wrong.