Indexing the archive…
Your Universe of Digital Possibilities
Muons from the sky pass through stone — fewer through more of it. Count them from inside a pyramid for months, and a small excess from one direction reveals a chamber no one has entered; from two or three sides, where it is. Find the hidden void from the counts alone, then turn around.
At sea level the muon intensity falls with zenith angle roughly as cos²θ — the slant path through the atmosphere is longer, and more of the parent pions and the muons themselves decay or stop on the way. A horizontal detector adds one more cos θ for its projected area.
Ionisation costs a muon about a = 2 MeV per g/cm²; above a few hundred GeV radiation (bremsstrahlung, pair production) adds bE with b ≈ 4 × 10⁻⁶ per g/cm². To cross a column density X it must start with Emin — about 46 GeV through 100 m of stone — and few do.
N counts observed where the model expects μ: Poisson noise is √μ, so a fixed fractional excess grows in significance as √t. A claim waits for 5σ — and for the excess to agree from more than one side, because the model of the stone is never perfect.
The Orfeo Edition’s ninth shadow is a room inside stone. The rebuild sees only counts; before turning around it can say how unlikely an excess is, never whether it is real; one detector’s depth is its null space, drawn; and the stone it assumes uniform is not — the prior is named, and its ghosts are shown. The muon’s own clock, slowed by its speed, is The Cone’s; an interior rebuilt from line integrals is The Scan’s; and an interior read from waves that cross it is The Core’s.