Issues in Quantum Gravity

这个研究项目的主要部分是解决关于空间和时间本质的基本问题。这是许多研究人员共同努力的一部分，他们正在建造需要更多地了解宇宙起源和黑洞中心发生的事情的结构。一些研究人员认为，这些答案将引出许多其他的答案，并最终形成一个完整的物理理论，解释我们宇宙的详细结构。将调查与各种方法有关的若干具体技术问题。其中一些人开发了所谓的量子引力“循环方法”的数学工具。另一些则涉及到我们的宇宙可能有超过我们所看到的三维空间和一维时间的可能性。例如，这个想法是“弦理论”方法的一部分。最后，一些研究使用物理定律来限制空间和时间的弯曲和翘曲方式。

The main portion of this research project addresses fundamentalquestions about the nature of space and time. It is part of a broadeffort shared by many researchers who are building the structures weneed to understand more about both the beginning of our universe and whathappens at the center of black holes. Some researchers believe thatthese answers will lead to many others, and eventually to a completetheory of physics that explains the detailed structure of ouruniverse. A number of specific technical questions will be investigated, relatingto various approaches. Some of these develop mathematical tools forthe so-called `loop approach' to quantum gravity. Others relate to thepossibility that our universe may have more than the three space andone time dimensions that we see. For example, this idea is part of theapproach known as `string theory.' Finally, some investigations usethe laws of physics to place constraints on the way that space and timecan curve and warp.