How the Solid World We Walk On Emerges: Inertial Persistence as a Victory Over

Why is the world we see so firm and predictable? While decoherence explains the loss of quantuminterference through environmental interaction, it does not fully account for the structural solidity ofmatter. We propose that classicality requires a second ingredient: inertial persistence. We introducethe Persistence Ratio PT = H/D, where H is the rest-mass energy (mc2) and D is the energy scale ofenvironmental decoherence noise. By analyzing particles within the Cosmic Microwave Background(CMB), we show that for electrons (PT ∼ 1025) and protons (PT ∼ 1042), mass-energy dominatesenvironmental jitter, allowing stable classical structures to emerge. We conclude that Newton’sF = ma is not a fundamental law, but an emergent description of states heavy enough to stand firmagainst the relentless quantum static of the cosmos.