A Landauer-Type Bound on Information Erasure at a Bounce

Erasure at the bounce is extraordinarily expensive per bit because the temperature is so high, yet the patch energy is also enormous, and the computation gives the precise fraction that results. The fraction is below unity: even consuming all available energy, a bounce cannot erase everything it contains, so complete information reset is forbidden by thermodynamics rather than merely unmodelled. The computation is performed from stated assumptions in a density-limited bounce, in which the neutron-branch limit density sets a maximum density, a finite bounce temperature, and a minimum horizon size. Headline values from the deposited calculation are: T_bounce_K = 3.28e+22; E_per_bit_J = 0.314; E_patch_J = 7.78e+27; max_bits_erased = 2.48e+28; I_patch_bits = 2.87e+38; fraction_erasable = 8.65e-11. The study is simulated and computed, not measured, and its conclusions are stated at the precision the stated assumptions support.