The weak equivalence principle (WEP) is the cornerstone of general relativity (GR). Testing it is thus a natural way to confront GR to experiments, which has been pursued for four centuries with increasing precision. MICROSCOPE is a space mission designed to test the WEP with a precision of 1 in 10¹⁵ parts, two orders of magnitude better than previous experimental constraints. After completing its two-year mission, from 2016 to 2018, MICROSCOPE delivered unprecedented precise constraints η(Ti,Pt)=[−1.5±2.3 (stat)±1.5 (syst)]×10−15 (at 1σ in statistical errors) on the Eötvös parameter between one proof mass made of titanium and another made of platinum. This bound allowed for improved constraints on alternative theories of gravitation. This review discusses the science beyond MICROSCOPE—GR and its alternatives, with an emphasis on scalar–tensor theories—before presenting the experimental concept and apparatus. The mission’s science returns are then discussed before future tests of the WEP are introduced.

中文翻译：

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显微镜下的引力视图

弱等效原理 (WEP) 是广义相对论 (GR) 的基石。因此，对其进行测试是将 GR 与实验对峙的一种自然方式，四个世纪以来，人们一直在追求这种方式，并且精度越来越高。MICROSCOPE 是一项旨在测试 WEP 的太空任务，其精度为 10 ¹⁵分之一，比以前的实验限制好两个数量级。在完成 2016 年至 2018 年为期两年的任务后，MICROSCOPE 交付了前所未有的精确约束 η(吨我,P吨)=[−1.5±2.3 (秒吨A吨)±1.5 (秒是秒吨)]×10−15 （在 1σ在统计误差中）在一个由钛制成的质量块和另一个由铂制成的质量块之间的 Eötvös 参数上。这个界限允许改进对替代引力理论的约束。在介绍实验概念和设备之前，这篇综述讨论了显微镜之外的科学——GR 及其替代方案，重点是标量-张量理论。然后在引入 WEP 的未来测试之前讨论任务的科学回报。