Editing Openai/6910af20-8f94-800c-af9c-840be0623d15 (section)

===== Why a “practical” swap is basically impossible (real physics) =====
* Core-collapse supernovae are triggered by internal collapse of an iron core when it can’t support itself (electron degeneracy pressure fails) — usually because the core reaches an effective Chandrasekhar mass or core processes (electron capture, photodisintegration) rob pressure support. You don’t just “nudge” a stable star into exploding without adding or rearranging huge amounts of mass/energy.
* A neutron star is orders of magnitude more tightly bound than a stellar core. Rough ballpark from basic gravity: - Gravitational binding energy of a typical neutron star (≈1.4 M⊙M_\odotM⊙, radius ~12 km): ~2×10^46 J. - Binding energy of a dense stellar iron core (≈1.5 M⊙M_\odotM⊙, radius ~10,000 km): ~3×10^43 J. - That means the neutron star is ≈700× more tightly bound than the core. Swapping a chunk of neutronium into a core would release an absurd amount of energy immediately — far more violent than a gentle nudge. (I ran the arithmetic to get those orders of magnitude so you can see the scale.)
* Tidal forces: bringing a compact object close to a red supergiant’s envelope will shred or accrete in complicated, extremely energetic ways. You’d get massive accretion, neutrino floods, shock heating, relativistic ejecta — not a neat, controlled “make-it-heavy-and-pop-in-1000-years” operation.
* Timescales and mass budgets: to change the evolutionary clock of a massive star on a ~100–1000 year timescale you’d need to add/redistribute of order fractions of a solar mass (or more), or trigger catastrophic core instabilities — which requires overcoming enormous energies and the star’s existing pressure/transport processes. That’s not “practical.”