I applied acoustic radiation pressure calculations to 12 megalithic sites. The results are fun.

The claim that ancient civilizations levitated stones with focused sound has been circulating in popular media for decades. Nobody had published the actual SPL requirements. So I ran them.

Using P_rad = p²/(ρc²) for a perfectly reflecting surface, I computed the required sound pressure level to levitate representative blocks from 12 sites (0.6–800 tonnes). Every block requires 183–195 dB SPL. The smallest (Puma Punku H-blocks, 0.6t) needs 183.4 dB — equivalent to coherent focusing of ~10⁷ jet engines onto 1 m². Three blocks exceed the 194 dB theoretical air limit outright.

I also applied the Storck–Thomsen–Popov vibration-friction framework to test whether airborne sound could reduce friction during transport. Ancient sources (94–118 dB) produce particle velocities ~10⁻¹ mm/s — roughly three orders of magnitude below the Thomsen criterion even with resonant amplification (Q = 50–500). The Finnegan et al. (2021) helicopter/sandstone-arch study provides independent corroboration.

The more interesting result: the 110 Hz "sacred frequency" claim (that megalithic chambers worldwide are deliberately tuned to ~110 Hz). A Rayleigh mode sweep across 144 human-scale rectangular room configurations shows 97.9% possess at least one mode within ±10% of 110 Hz. Meanwhile 125 Hz and 150 Hz both hit 100%. The King's Chamber has 199 modes below 200 Hz. The claim fails on geometric inevitability alone, before you get to the evidential problems (n=6, single study, zero replications in 30 years).

Paper: doi.org/10.5281/zenodo.19227947