Chandrasekhar's Number, Derived in the Open: What the Limit Assumes, and What the Sky Charges for Each Assumption

Most famous numbers in physics are measurements. The Chandrasekhar mass is a derivation — one of the few places where a fundamental limit on what nature can build falls out of constants and structure alone — and this paper re-derives it in the open, from the electron gas up, landing at M_Ch = 1.456 M_☉ for a carbon–oxygen composition, computed in my notebooks from the CODATA constants rather than quoted. The derivation is then treated the way my census treats every classic: its assumed steps are itemized and priced one by one — zero temperature, no rotation, no magnetic field, Newtonian gravity, an ideal gas of electrons on a passive ion lattice — and against each price stands what the sky actually charges: a class of Type Ia supernovae (SN 2003fg and its siblings) whose progenitors weighed in at 2.1 M_☉ or more, forty-four percent above the derived wall. The resolution is not that the derivation is wrong; it is that the exploding objects bought their extra mass through exactly the doors the derivation closed — rotation and merger — and each door's price is computed here. Grade: THE NUMBER IS DERIVED — EVERY ASSUMPTION IS PRICED, AND THE VIOLATORS PAID THROUGH THE PRICED DOORS. This paper stands outside my work on the vacuum catastrophe; it draws nothing from that work and repairs nothing in it.