一増一減 (いちぞういちげん) — 16,800,000-year period over which a human lifespan increases from ten years to 84,000 years (by one year per century) and then decreases back to ten (by one year per century)
一増一減
16,800,000-year period over which a human lifespan increases from ten years to 84,000 years (by one year per century) and then decreases back to ten (by one year per century)
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