spacefood
Explanation
The Joke
An astronaut radios mission control in a panic: there is no food on their two-year mission and nobody packed any. Mission control responds that it is "an experiment." The astronaut's daughter, an engineer, only knew how to make glitter out of protein, fiber, and micronutrients -- so she poured some into the astronaut's suit before they left. According to "the theory of glitter non-conservation," every time you check your suit there will be more glitter. The astronaut reacts with horror ("My God"), mission control calls it "everywhere," and someone adds, "That is not for us to know."
The Humor
The comic plays on the well-known real-world observation that glitter is virtually impossible to get rid of -- once introduced, it multiplies and spreads to every surface, every crevice, and every piece of clothing you own. The joke elevates this mundane annoyance to a physics-level law ("the theory of glitter non-conservation"), treating the mysterious self-replicating nature of glitter as a genuine scientific phenomenon. The idea that an engineer can only convert nutritious food into glitter is an additional absurdity, and the horrified reactions from mission control frame glitter contamination as an existential cosmic threat rather than a mild craft-supply nuisance. The final line -- "That is not for us to know" -- parodies the tone of unknowable cosmic horror, as if glitter propagation is a mystery beyond human comprehension.