String theory.
String theory.
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DOI：
10.1073/pnas.95.19.11039
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发表时间：
1998-10
影响因子：
11.1
通讯作者：
Brian R. Greene;David R. Morrison;Joseph Polchinski
中科院分区：
文献类型：
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作者：
Brian R. Greene;David R. Morrison;Joseph Polchinski
粒子物理学家在本世纪花了很多时间，以各种形式努力解决一个基本问题：描述自然所需的基本自由度是什么？控制其动力学的定律是什么？首先是分子，然后是原子，然后是质子和中子等“基本粒子”，所有这些都被揭示为复合物体，其组成可以作为更基本的自由度来研究。目前粒子物理学的“标准模型”已经有将近25年的历史了，有很多实验证据支持它，它由6个夸克、6个轻子、4种力和尚未被观测到的希格斯玻色子组成，它的内部迹象表明，它也可能是揭示真正基本自由度的道路上的又一步。标准模型对小至10 - 16厘米的距离是有效的，并且有一些证据（例如通过推断四种力的强度来确定它们可能变得难以区分的距离尺度）表明，下一级结构将仅在大约10 - 32厘米的距离尺度上被检测到，远远超出了我们在实验室测量的能力。运动和重力的研究在本世纪也经历了几次修正。为了使牛顿的运动理论与实验观察到的光速的恒常性相协调，需要引入狭义相对论。狭义相对论非常引人注目地坚持认为，空间和时间是密切相关的，就像同一事物的不同面……
Particle physicists have spent much of this century grappling with one basic question in various forms: what are the fundamental degrees of freedom needed to describe nature, and what are the laws that govern their dynamics? First molecules, then atoms, then “elementary particles” such as protons and neutrons all have been revealed to be composite objects whose constituents could be studied as more fundamental degrees of freedom. The current “standard model” of particle physics—which is nearly 25 years old, has much experimental evidence in its favor and is comprised of six quarks, six leptons, four forces, and the as yet unobserved Higgs boson—contains internal indications that it, too, may be just another step along the path toward uncovering the truly fundamental degrees of freedom. The standard model is valid to distances as small as 10−16 cm, and there is some evidence (such as that obtained by extrapolating the strengths of the four forces to determine the distance scale at which they might become indistinguishable) that the next level of structure will be detected only at a distance scale of roughly 10−32 cm, far beyond our abilities to measure in the laboratory. The study of motion and gravity also has undergone several revisions during this century. Reconciling the Newtonian theory of motion with the experimentally observed constancy of the speed of light required the introduction of special relativity, which quite remarkably insists that space and time are intimately related, much as different faces of the same …