悖论：有什么经典的悖论

What are some great paradoxes?Aiman Kamal, Teenage Mutant Ninja QuoranAnswered Jun 7Here are some paradoxes that I found to be interesting:The Fermi Paradox: The Fermi Paradox speaks to the contradiction between the likelihood of alien life and lack of evidence for it. This paradox is named after physicist Enrico Fermi who first proposed this in 1950. It ponders over the question that if the universe is so big and old, and there are countless opportunities for life, why have we not found aliens?The Paradox of the heap: Also known as the Sorites paradox, this paradox goes something like this: Imagine a heap of sand. Take away one grain of sand, and you'd probably still call it a heap. Keep taking away one grain of sand at a time. At what point is it no longer a heap? What is a heap anyway? :|The Twin Paradox: It is possible to be older than your identical twin. Einstein's theory of special relativity says this is possible because time can tick at different speeds on how you are moving.Source: Curosity