科学没有尽头There Is No End of Science
Brett：爱丁顿的实验是所谓关键性检验（crucial test）的绝佳例子，它可以说是科学的至高境界。
如果我们做一个检验，结果与我们持有的某个特定理论不符，那确实是个问题。但这并不意味着该理论被证伪了。如果你证伪了手里唯一的理论，你该跳到哪里去？你没有其他选择。
假如我们明天做一个科学检验，结果与广义相对论不一致，那又怎样？广义相对论没有替代品。事实上，这些年来确实有过一些实验，似乎与广义相对论不一致。结果如何？它们全都被证明是有缺陷的。如果让你在"广义相对论被你的检验证伪了"和"你的检验有缺陷"之间二选一，那就认定是你的检验有缺陷吧。
就爱丁顿的实验而言，当时我们有两个可行的引力理论：一边是牛顿的万有引力理论，另一边是爱因斯坦的广义相对论。
你描述的那个日食时光线弯曲多少的实验，正是对当时情形的正确描述。我们并不是在某种最终意义上证明了广义相对论是正确的；相反，我们证伪了牛顿的引力理论。牛顿的理论被排除了，因为它与检验结果不一致，而广义相对论与检验结果一致。
这并不意味着广义相对论就是科学的最终定论。它意味着它是我们目前拥有的最佳理论，而且有很多理由让我们认为，归根结底广义相对论最终很可能是错的。这是这种世界观的另一个方面：我们永远不会有最终定论——而这恰恰是好事。这是乐观的，因为它意味着我们可以不断改进，不断取得进步，不断发现新事物。科学没有尽头。
人们曾经担心有一天进步会停滞，科学会终结。事实上，我们正处在无限的开端，而且将永远处在无限的开端，正因为我们能够改进我们的观念。
我们是会犯错的人类。我们的理论没有一个是完美的，因为我们并不完美。我们创造知识的过程也不完美，它容易出错。
Brett: Eddington’s experiment is an excellent example of what’s called a crucial test, which is sort of the pinnacle of what science is all about.
If we do a test and it doesn’t agree with a particular theory that we have, that’s problematic. But that doesn’t mean that it refutes the theory. If you were to refute the only theory that you have, where do you jump to? You don’t have any alternative.
If we were to do a scientific test tomorrow and it was inconsistent with the theory of general relativity, then what? There is no alternative to general relativity. In fact, there have been experiments over the years that seem to have been inconsistent with general relativity. Guess what? They’ve all turned out to be faulty. If you had to choose between whether or not general relativity has been refuted by your test or your test is flawed, go with the fact that your test is flawed.
In the case of Eddington’s experiment, we had two viable theories for gravity. We had Newton’s theory of universal gravitation on the one hand and we had Einstein’s general theory of relativity on the other.
The experiment you described of how much the light bends during a solar eclipse is the correct way of describing what happened. It is not that we showed that general relativity was correct in some final sense; rather, we refuted Newton’s theory of gravitation. Newton’s theory was ruled out because it was inconsistent with the test, while general relativity was consistent with the test.
This doesn’t mean that general relativity is the final word in science. It means that it’s the best theory we have for now, and there’s a whole bunch of reasons that we might think general relativity ultimately has to be false in the final analysis. This is another aspect of the world view that we never have the final word—and that’s a good thing. That’s optimistic because it means we can keep improving, we can keep making progress, and we can keep discovering new things. There is no end of science.
People have feared that one day progress will come to a halt, that science will end. In fact, we are at the beginning of infinity, and we will always be at the beginning of infinity precisely because we can improve our ideas.
We’re fallible human beings. None of our theories is perfect, because we aren’t perfect. The process by which we create knowledge isn’t perfect, either. It’s error-prone.