Decay Time
身近なものが分解されるまでの時間を当てよう · バナナの皮からガラス瓶まで。
About Decay Time
Decay Time is a quick estimation game about how long everyday things take to break down in nature. A banana peel? About a month. A plastic bottle? Around 450 years. A glass bottle? Closer to a million. Each round shows one item and a handful of durations · pick the closest one and keep your streak alive.
Real numbers, coarse on purpose. The durations come from the widely-cited decomposition tables used in environmental education (NOAA's marine-debris material and the posters derived from it). Exact times depend on conditions, so the game tests magnitude sense · weeks vs decades vs centuries · not lab precision.
Choose what to study. Play the full mix, or filter to nature & food (peels, paper, cotton, wool) or human-made materials (plastics, metals, glass). The distractor durations close in as your streak grows, so long runs demand genuinely sharper estimates.
Part of the PlayMemorize family of brain-training games.
FAQ
Q: What is Decay Time?
A quick estimation game: see an everyday item · a banana peel, a tin can, a plastic bottle · and pick how long it takes to break down in nature. One wrong answer ends the streak, and your best score is saved locally in your browser.
Q: Where do the decomposition times come from?
From the widely-cited environmental-education tables, principally NOAA marine-debris material. Real decomposition depends on moisture, temperature and burial, so the game uses coarse, defensible magnitudes · the skill being trained is magnitude sense, not memorising lab data.
Q: Can I study just one category?
Yes. The picker on the start screen filters the pool to nature & food items, human-made materials, or everything. Each category keeps its own best streak.
Q: How does it get harder?
Two ways: as your streak grows the wrong answers move closer to the true duration (450 vs 600 years instead of 1 month vs 1 million years), and an extra answer option joins the row.
Q: Can I print it as a worksheet?
Yes. Decay Time supports the printable worksheet generator at /worksheets · each problem prints with lettered duration choices and an answer key, a ready-made handout for environment and recycling units.
