"If a tree falls in a forest and no one is around to hear it, does it make a sound?" is a philosophical thought experiment that raises questions regarding observation and perception.
「假如一棵樹在森林裡倒下而沒有人在附近聽見，它有沒有發出聲音？」是一個哲學思考實驗，提出關於觀察和現實知識的問題。