Secantha: Airmass Sec Z
Cosmology & the Sky arc, page 155 of 193. Back to The Pixelated Physics Universe
Who they are
Secantha has one line, and says it often: “Sec z rising. so is my despair.”
Secantha is a character of the Cosmology & the Sky arc: drawn in pixels, ruled by one piece of real physics, and never allowed to break it.
The physics
Airmass X ≈ sec z for zenith angles below about 60°; extinction grows with X.
$$ \begin{gathered} X \approx \sec z \quad (z \lesssim 60^\circ) \end{gathered} $$
| Symbol | Meaning | SI unit |
|---|---|---|
| $X$ | airmass | — |
| $z$ | zenith angle | — |
Sources
Crossovers
Secantha meets Duskward (Astronomical Twilight). Duskward waits for the Sun to sink 18° below the horizon. Secantha races a target sinking toward it, where the airmass, roughly sec z, grows and extinction rises.
Secantha meets Slithera (Atmospheric Dispersion). Secantha's target is setting into thicker air. Slithera warns that atmospheric dispersion grows with the zenith angle too, so the slit should be aligned to the parallactic angle.
Wear the lore
Concept keywords: Airmass Sec Z, Secantha, Cosmology & the Sky, physics lore, Pixelated Physics