Paradox, paradox and paradox
I have seen the word in many places, and I have been eager to know the exact meaning of it. Then I saw a clear definition of it in a book, so I wrote it down for us to share.
First, the paradox means something that contains opposite idea, that is to say, it cannot be judged to be true or false logically. The most famous example is the paradox of Russll. It goes like that, if a set contains itself, we say it has a quality A (an example is the set of all sets); now we have a set B that contains all sets that do not have a quality A; the question is whether B contains itself or not. We can see that if B contains itself, it has a quality A, so it do not contains itself; if B do not contain itself, it do not have a quality A, so it is an element of B. The result is against each other, and that is a paradox.
Then, the paradox means something that sounds to be true but actually is wrong. The most well known is Chino’s. One is the problem of the racer and the tortoise, as everybody knows it, I want to talk about another one. Is an arrow moving while it is approaching its target? Chino said no. An arrow has its permanent length, and it has an exact position at an exact time, so it is still at one certain time, and all this kind of time, but as we know, the sum of still does not add up to moving. This question was said to touch the deepest contradiction in moving, and kept puzzling people until Max put an end to it.
At last, it means something that seems to be wrong but actually is true. There are many famous examples, Olbers’ paradox is a good one. He was born in a period that people generally believed that the university was still and had no boundary. He doubted about it, so he gave a paradox. It said that if the university was still and had no boundary, then our eye sight would end in a star, so the sky in the night should be bright.
These three meanings are obviously different from each other and have the same English name, but when translated into Chinese, they went confusing, because the Chinese name of them are different. There are so many misuses on the Internet. So, I think we should clarify these words better.