And Jenner, because he was a trained physician, because he knew something about the scientific method, did something that these more ancient healers had not done in the past, was that he wrote down what he did.

而詹纳,因为他是个受过训练的医生,懂得一些科学方法,他做了那些古老的医生们没有做的事,就是记录了自己的所作所为

耶鲁公开课 - 生物医学工程探索课程节选

It's a secret number so that if Julius Caesar scrambled his message with the key 13, well, then the recipient had better know what that number is or realistically, -- and this is why it's kind of hard to buy -- into some of these age old algorithms, -- what would an alternative approach be to figuring out Julius Caesar's messages to his generals if he didn't know that secret number was 13?

它是一个机密的数字，以至于,如果凯撒大帝使用密钥13加密了它的消息，然后接收者最好知道那个数字是什么,实际上--这就是为什么很难,破解这些古老的算法-,有什么变换方法使凯撒大帝的将军,可以解密凯撒大帝的消息，如果他不知道,那个机密数字是13呢？

哈佛公开课 - 计算机科学课程节选