PENT-3, laid on the real atom — and here the trit stops being a label and becomes the physics. A hydrogen atom in the transcription cycle has exactly three things it can do with a photon: absorb (−), hold (0), emit (+). That is the direction trit, sign for sign. And the witness fact that makes it faithful, not just neat: emission is the time-reverse of absorption — same 10.2 eV, same Lyman-α, opposite arrow — which is precisely NEG flipping − to +. The held excited state is the one configuration going nowhere: the fixed point, t = 0, the g·g seam.
photon in, n=1→2 · ADD/WRITE · the Si gate (needs the gap)
0 hold
excited n=2, held · NOP · the only self-negation
+ emit
photon out, n=2→1 · DUMP/READ · the Cu dump (no gap)
Why NEG is real here
absorb
+10.2 eV in, 121.6 nm
emit
−10.2 eV out, 121.6 nm
NEG
flips the sign = time-reversal of the same transition
fixed pt
the held state — its own time-reverse
Status discipline
LiteralAbsorption and emission are genuine time-reverses (same energy, opposite direction) by microscopic reversibility; the excited state is metastable/held; 10.2 eV, 121.6 nm Lyman-α are real.
BridgeLabelling the three photon-actions as the trit −/0/+, and NEG as the time-reverse; the held state as the ⟨…0…⟩ fixed point.
SpeculativeThat the atom "is computing" a trit, and the opcode names, are the frame. The atom does physics; PENT-3 is a faithful label because the physics is genuinely three-valued and sign-reversible at the seam.