translation.en: Now when these ideas were first developed, there were only about five different candidate shapes, so you can imagine analyzing them one-by-one to determine if any yield the physical features we observe.
translation.zh: 当这些想法首次推出的时候， 只有5个候补形状， 你可以想象到 一个一个分析它们 来决定哪一个符合 我们观察的物理特征。