What If Spacetime Is Made of Strings? A Speculative Sketch on Black Holes, the Big Bang, and Cosmic Recurrence

`This is a revised (v2) version of the earlier preprint. The original was framed as an academic paper (abstract, formal structure, reference list), which overstated what the work actually is. This version reframes it honestly as an essay — the continuation of a companion piece on the bootstrap uniqueness of string theory, asking: if strings are the fundamental constituents of reality, what would they physically do? The essay develops a speculative picture in which spacetime emerges from a face-centered cubic lattice of strings, with a Hawking-thermodynamic wall whose thickness follows Δ(M) = ℓ_s · ln(1/p_c) / ln(4GM/ℓ_s), and proposes the Big Bang as a percolation-driven fracture event. Unlike the original framing, this version foregrounds the central open problem: the predicted wall thickness for black holes lies below the Planck length, where the formula's physical meaning is unresolved. The essay was developed by a non-physicist in conversation with AI assistants (Claude Sonnet 4.6, OpenAI's o3), which checked the reasoning and calculations, and includes an explicit account of the limits of the author's own understanding. Companion essay: https://doi.org/10.5281/zenodo.20677635`