TED演讲:科学解释之新探(5)

 　　Why a marriage contract and not any other reason for regular annual action? 为什么是一纸婚书而不是其他什么原因使普西芬妮定期往返呢？

　　Here is one. Persephone wasn't released.  我且来举个例子：普西芬妮并没有被放走
　　She escaped, and returns every spring to take revenge on Hades, with her Spring powers. 她逃走了，每年春天又回冥府找哈德斯报仇，用她春天的神力
　　She cools his domain 1 with Spring air,  她让春风给冥界降温
　　venting 2 heat up to the surface, creating summer.  热气排到地上，成了夏天
　　That accounts for the same phenomena 3 as the original myth.  这个说法和先前的神话能解释同样的现象
　　It's equally testable.  而且同样可以检验
　　Yet what it asserts about reality is, in many ways, the opposite. 可是它对现实的描述，断言，却和刚才的在许多方面正好相反
　　And that is possible because  这看似矛盾的情况之所以存在
　　the details of the original myth are unrelated to seasons, except via the myth itself. 是因为原先那个神话的诸多细节? 除了在这则神话的背景中外，与季节都没有什么联系
　　This easy variability is the sign of a bad explanation, 这种很随意的可变性正是坏解释的标志
　　because, without a functional 4 reason to prefer one of countless 5 variants 6, 因为当没有什么关于细节的解释作用的理由能使我们选择千万种可能解释中的一个
　　advocating one of them, in preference to the others, is irrational 7. 唯独支持这一个而抛弃其他便是不理性的
　　So, for the essence of what makes the difference to enable progress, 所以，产生变革推进发展的本质原因
　　seek good explanations, the ones that can't be easily varied 8, 就是追求好解释，那些为了保证解释现象的能力
　　while still explaining the phenomena.  而不能被轻易改变的解释
　　Now, our current explanation of seasons is that the Earth's axis 9 is tilted 11 like that, 我们现在对季节的解释是说地球的转轴像这样倾斜着
　　so each hemisphere tilts 12 toward the sun for half the year, and away for the other half. 所以每个半球在半年中倾向太阳另外半年远离阳光
　　Better put that up.  最好放出来看看
　　That's a good explanation: hard to vary,  这就是个好解释：很难改动
　　because every detail plays a functional role.  因为每一个细节都对有至关重要的解释作用
　　For instance, we know, independently of seasons,  比如说，我们不用明白季节就知道
　　that surfaces tilted away from radiant heat are heated less, 背向发光物体的表面受热的程度较小
　　and that a spinning sphere, in space, points in a constant direction. 空间中自转的这个球体指向同一个方向
　　And the tilt 10 also explains the sun's angle of elevation 13 at different times of year, 地轴的倾斜也解释了太阳在一年中不同的仰角
　　and predicts that the seasons will be out of phase in the two hemispheres. 并预测两半球的季节情况正好相反
　　If they'd been observed in phase, the theory would have been refuted. 如果观察显示它们相同，理论就被驳倒了
　　But now, the fact that it's also a good explanation,  可是它作为一个好解释
　　hard to vary, makes the crucial difference.  一个难以更改的解释，这一点才是最重要的区别
　　If the ancient Greeks had found out about seasons in Australia, 如果古希腊人得知了澳洲季节的更替
　　they could have easily varied their myth to predict that. 他们很容易就能修改这个神话，然后预测说，
　　For instance, when Demeter is upset,  比如，当迪米特为女儿忧愁时
　　she banishes 14 heat from her vicinity, into the other hemisphere, where it makes summer.  她把热气从四周驱赶出去，赶到另一个半球，形成夏天
　　So, being proved wrong by observation,  这样看来，尽管被观察所否决
　　and changing their theory accordingly,  并被迫据此修改他们的理论
　　still wouldn't have got the ancient Greeks one jot 15 closer to understanding seasons, 古希腊人并没有离对季节的理解进了那怕一步
　　because their explanation was bad: easy to vary.  因为改过的解释仍旧是坏解释：它太易变了
　　And it's only when an explanation is good that it even matters whether it's testable. 而只有当好解释存在，它是否可以验证才值得考虑