Reasoning:
- Charge sign: with equal u,d,s numbers strange matter is neutral; the strange-quark mass suppresses s occupancy (exclusion-principle kinematics), giving Z/A > 0. Gluon exchange raises s population (repulsion is weaker for pairs involving heavier quarks), and cranking it far enough turns Z negative — but the same repulsion unbinds the quark matter, compensable only by unreasonably low bag constants. Early claims of negative strange matter over broad parameter ranges rested on incorrect applications of perturbative QCD.
- Positive-case safety: a positive strangelet immediately forms a strangelet-atom; the strong force it presents to other atoms has the same well-known long-range form as for nuclei, and fusion is suppressed by the barrier-penetration factor exp(-Z1 Z2 K). Even the most favorable case (charge 1 on hydrogen) sits at the level of room-temperature H-H fusion, whose very observability is debated; each unit of charge acquired multiplies the exponential suppression. The worked example — thermalized strangelet with the full collision’s baryon number 396 and Z = 6 on hydrogen, standard nuclear reaction theory — gives ~1e-200000 per second.
- Consequence for the danger hypothesis: only the negative branch is dangerous, and a negative strangelet of given A needs proportionately more s quarks (A=20, Z=-1 needs 22 s quarks vs 12 for Z=+4), compounding its production penalty.
Step 6 verdict
Verdict: approved (checked). Two traced steps. (1) Charge sign: s-quark mass suppresses s occupancy in Fermi-gas kinematics, giving Z/A > 0; the only lever to negative Z - strong gluon-exchange effects - simultaneously unbinds the matter unless the bag constant is unreasonably low; a coherent two-horned inference. (2) Positive-case harmlessness: standard Gamow barrier penetration exp(-Z1 Z2 K); even the most favorable case (Z=1 on hydrogen) sits at room-temperature H-H fusion levels, and the A=396, Z=6 worked example’s ~1e-200000/s is ordinary nuclear reaction theory. Hidden premise surfaced: no significant free-neutron flux in ordinary terrestrial matter (neutron absorption being the one Coulomb-free growth channel a positive strangelet retains) - grantable for the Earth-safety conclusion. Conditional on the Fermi-gas/bag-model premises the inferences hold; premise truth is steps 7-8.