aka Theseus’s Paradox 船舶悖論

is a thought experiment and paradox about whether an object is the same object after having all of its original components replaced over time, typically one after the other.

• 思考:
  • 如果一艘船上的木板逐塊被替換，直到所有的木板都換成新的，那麼這艘船還是原來的那艘船嗎?
  • 如果把舊木板收集起來，重新組裝成另一艘船，那麼哪一艘才是真正的「原船」?
• This can be applied to our personal identities as well. → 身體的細胞不斷更新，思想也在變化，那麼我們還是原來的自己嗎？

  • The average age of all cells in the human body is 7–10 years.

    Every seven years, human beings transform into entirely new versions of themselves. This idea stems from the biological principle that our bodies replace virtually all their cells over a seven-year cycle. The person you are today doesn’t share a single cell with the version of you from seven years ago.

  • 不同細胞的更新週期

    • 🧠 神經細胞 (大腦) → 幾乎不會更新，大部分人一生都帶著同一批神經元 (但有少量例外，如海馬迴的神經元可能會再生) 。
    • 💀 骨細胞 → 約 10 年完全更新一次。
    • 🩸 紅血球 → 約 120 天更新一次。
    • 🧑‍🦲 皮膚細胞 → 約 2–4 週就會更新一次。
    • 🍽️ 腸道細胞 → 內壁細胞大約 2–5 天就會更新一次!
    • 💪 肌肉細胞 → 主要是修復而非完全更換，部分可持續數年。