Albert Einstein gave us two of the most precisely confirmed theories in physics — and they describe time dilation through completely different mechanisms, without a common physical foundation.
Special Relativity (1905)
A clock moving at velocity v runs slow by the factor √(1 − v²/c²). Einstein derived this from two postulates: the laws of physics are the same in all inertial frames, and the speed of light is constant. The formula is exact. But what physically happens inside the clock? Einstein provided no answer. The slowing is real but the mechanism is absent.
General Relativity (1915)
A clock near a massive object runs slow by the factor √(1 − Rs/r). This follows from the geometry of curved spacetime — mass warps the fabric of space and time, slowing processes near it. Again, the formula is exact. But why does curved geometry cause a clock to tick slower? No physical process inside the clock is identified.
What Einstein Left Open
SR and GR produce the same observable effect through different machinery. One says relative velocity is the cause; the other says curved spacetime is the cause. They share no common physical substrate. Neither tells you what is happening inside the clock. And they are mathematically incompatible at their foundations — unifying quantum mechanics with gravity has been the central unsolved problem in physics for a century.
BFUT Paper 22: One Mechanism for Both
The Spaticle field has a finite total propagation capacity. Every physical process — motion through space, internal clock evolution, quantum phase changes — draws from this same budget. The central equation is:
c² = v_spatial² + v_internal²
The total propagation budget is always c². Motion and internal evolution share it. Their squares sum exactly to c².
When an object moves at velocity v, it consumes v² of the budget for spatial motion. The remainder, c² − v², is available for internal evolution. The internal rate becomes v_internal = √(c² − v²), giving efficiency η = v_internal/c = √(1 − v²/c²). This is exactly Special Relativity's formula — derived from a physical substrate, not from abstract postulates.
Near a massive object, substrate deformation reduces the locally available propagation capacity. Every process at that location — atomic, nuclear, biological — runs at the reduced rate. This reproduces General Relativity's formula from the same substrate mechanism.
Both effects compound: η_total = η_kinematic × η_gravitational. SR and GR are not two separate theories in BFUT — they are two cases of one equation applied to one physical medium.
Photons: The Clearest Demonstration
A photon moves at exactly v = c. Substituting into the budget equation: v_internal² = c² − c² = 0. The photon has zero internal propagation capacity. It cannot evolve internally. It accumulates exactly zero proper time — it does not age. This is why photons travel from the Big Flare-Up era without ageing. It is not a postulate of relativity. It is a consequence of the propagation budget.