Editing Openai/6946e998-79f0-8007-9a65-19828450838d (section)

==== Using: ====
* N₀ = 10⁹ “Earth-ish HZ” planets ever in the Milky Way (already pessimistic), and
* Six pessimistic filters

fclimate=0.1,  fvolatiles=0.1,  fplate=0.1,  fsurvive=0.1,  flife=0.01,  fintel=0.01f_{\text{climate}} = 0.1,\;
f_{\text{volatiles}} = 0.1,\;
f_{\text{plate}} = 0.1,\;
f_{\text{survive}} = 0.1,\;
f_{\text{life}} = 0.01,\;
f_{\text{intel}} = 0.01fclimate=0.1,fvolatiles=0.1,fplate=0.1,fsurvive=0.1,flife=0.01,fintel=0.01
you get:

Nintel, ever≈109×(0.1)4×(0.01)2≈10N_{\text{intel, ever}} \approx 10^9 \times (0.1)^4 \times (0.01)^2 \approx 10Nintel, ever≈109×(0.1)4×(0.01)2≈10
: 

A few important notes:
* Every single factor I chose is intentionally on the pessimistic side of what current literature and simple reasoning would support.
* If any of these fractions is higher by even an order of magnitude, N jumps rapidly (e.g., making f_life or f_intel = 0.1 instead of 0.01 boosts N by ×10 each).
* If you pushed one or two factors much lower (e.g., f_life = 10⁻⁴), you quickly drive N ≪ 1, which conflicts with the fact that at least one such world (ours) clearly exists—anthropic selection then forces you to revisit the assumptions.

So, under a stack of quite harsh assumptions that still respect basic empirical constraints, a reasonable “pessimistic but not absurd” answer is:

>