This article discusses the possibility of some outlandish tropes from time travel fiction, such as people reversing in age as they time travel or the universe being destroyed because a time traveler kills their ancestor. First, I discuss what type of possibility we might have in mind, detailing ‘close possibility’ as one such candidate. Secondly, I argue that—with only little exception—these more outlandish tropes fail to be closely possible. Thirdly, I discuss whether these outlandish tropes may nevertheless be more broadly possible (e.g., metaphysically or logically possible), arguing that whether they are or not depends upon your favored metaphysics of the laws of nature.

中文翻译：

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时间旅行的可能性

本文讨论了时间旅行小说中一些奇怪比喻的可能性，例如人们在时间旅行时年龄逆转，或者宇宙因为时间旅行者杀死了他们的祖先而被摧毁。首先，我讨论我们可能想到的可能性类型，详细说明“接近的可能性”作为这样的候选者。其次，我认为——除了极少数例外——这些更古怪的比喻不太可能发生。第三，我讨论这些古怪的比喻是否可能更广泛地可能（例如，形而上学或逻辑上可能），认为它们是否取决于你喜欢的自然法则形而上学。