More than 65 years ago, John Wheeler suggested that quantum uncertainties of the metric would be of order one at the Planck scale, leading to large fluctuations in spacetime geometry and topology, which he termed ‘spacetime foam.’ In this review I discuss various attempts to implement this idea and to test it, both theoretically and, to a lesser extent, observationally.

中文翻译：

---

时空泡沫：回顾

65 多年前，约翰·惠勒 (John Wheeler) 提出，该度量的量子不确定性将在普朗克尺度上达到一阶，导致时空几何和拓扑结构出现大幅波动，他将其称为“时空泡沫”。在这篇评论中，我讨论了实现这个想法的各种尝试，并在理论上和较小程度上通过观察来测试它。