Teach & case
Help a near-peer reason through the idea — when you explain it, you understand it best — then read the real decision it comes from.
Help Rin reason about the rule
What you've shown you can teach
A real case · you decide
Rin and the generative piece they "lost"
Rin — a creative-coder who made a stunning piece with a "random" generator and now thinks it is gone forever
Rin's sketch calls random() to place shapes, seeded by a number. At seed 42 it produced something gorgeous — Rin closed the tab without saving the image, reran with a new seed, and got something totally different. Rin is crushed: "It was random, so that exact piece is gone forever." Is it?
A seeded pseudo-random generator isn't truly random — it's DETERMINISTIC. Given the same seed, it emits the exact same sequence of "random" numbers, so the same rule + seed 42 rebuilds the identical piece, pixel for pixel.
"Random-looking" and "unrepeatable" are different. The output looks unpredictable, but the seed is its complete memory: nothing else is stored, and nothing else is needed. Change the seed and you explore; restore the seed and you return.
Rin thinks the seed-42 piece is unrecoverable because it was "random." Is it actually lost?
Rin now wants every gallery visitor to see a DIFFERENT piece. Should Rin hard-code seed 42?
Rin's takeaway is a coder's superpower: write down the seed and the exact piece is yours forever, and turn the seed into a knob to generate a whole family of variations on purpose.