Transport Separates Before Biology

Diffusion Spreads Mean Square

two D t is the claim

Diffusion spread is checked as a mean-square budget. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Diffusion uses a coefficient and time

The diffusion coefficient is 2 square metres per second and the time is 3 s.

D=2 m2/s,t=3 sD=2\ \text{m}^{2}/\text{s},\quad t=3\ \text{s}
Mean square spreadThe spread claim is an x-squared budget, not a distance marker.packetmean square

Mean square spread is two D t

The mean square spread is 12 square metres. This is not a square-root distance or a full distribution.

⟨x2⟩=2Dt=12 m2\langle x^{2}\rangle=2Dt=12\ \text{m}^{2}
Mean square spreadThe spread claim is an x-squared budget, not a distance marker.packetmean square