Title: A Century of Gravity: 1901--2000 (plus some 2001) Show Chinese title

Title: 20世纪的引力：1901--2000（包括一些2001）

Abstract: This lecture consists of two parts. The first is a (totally unsystematic) survey of some of the high points in the evolution of gravity and its successors, primarily in the course of the past century. The second summarizes some new work on surprising properties of higher $(> 1)$ spin fields in cosmological backgrounds: the presence of $\L$ gives rise to discrete sets of massive models endowed with gauge invariances, that divide the ($m^2, \L$) plane into unitary and non-unitary phases. The unitary region common to fermions and bosons shrinks to flat space ($ \L \to 0 $) as their spins increase. Show Chinese abstract

Abstract: 本讲座分为两部分。 第一部分是对引力及其后续理论在进化过程中的某些高点的（完全无系统的）概述，主要是在过去一个世纪中。 第二部分总结了一些关于宇宙学背景中更高$(> 1)$自旋场的意外性质的新工作：$\L$的存在导致了具有规范不变性的质量模型集合，这些模型将($m^2, \L$)平面划分为幺正和非幺正相。 随着自旋的增加，费米子和玻色子共有的幺正区域收缩到平坦空间($ \L \to 0 $)。