Mainstream astrophysical theories fail to reasonably explain the differences in jet ranges of central black holes in spiral galaxies, nor can they clarify the underlying mechanism enabling ultra-large-scale black hole jets to propagate stably across tens of millions of light-years. Based on the Unified Theory of Light Origin, this paper redefines the essence of black holes and the core motion properties of photons, and overturns the traditional hypothesis of power-driven jets. The study demonstrates that the core of black holes at the centers of spiral galaxies is a photon soup composed purely of high-energy gamma photons. Photons inherently travel at the speed of light, cannot be accelerated or decelerated, and require no external force or kinetic energy supply. The spiral galactic structure has two exclusive functions: accreting matter to continuously generate high-energy photons, and gradually narrowing the polar escape channels to form high-density gamma photon beams. Jets of ordinary black holes suffer insufficient total photon volume and low energy density; during propagation, they rapidly cool and undergo particleization, and newly generated massive particles form barriers to block subsequent beams, leading to quick jet dissipation. Black holes in late-evolution spiral galaxies possess extreme photon density and ultra-high overall energy. Their beams stay above the particleization threshold over tens of millions of light-years without cooling down and particleizing, eliminating self-blocking from internal generated particles, thus supporting stable ultra-long-distance jet propagation. The proposed mechanism perfectly matches the observed jet characteristics of supermassive central black holes in spiral galaxies at young, middle-aged and elderly evolutionary stages. It also distinguishes short-lived stellar-mass small black holes and covers the evolutionary laws of all types of black holes, realizing a self-consistent unified interpretation of black hole jet phenomena.
Jiaqing Yan (Sat,) studied this question.