我有一個問題，那就是在人類可觀測宇宙中，到底有多少原子？How many atoms are there in the human observable universe?

如果一切都是由原子构成的，我们知道宇宙中有多少原子吗？

举个例子，从人一出生开始计算，一个普通人体内大约有 780 亿个原子（今天的内容，全是各种大数，以至于我自己念的时候，舌头都打结了）。鉴于一个人体内就有如此多的原子，你可能会认为要确定整个宇宙中有多少原子是不可能的。其实，你是对的， 因为我们不知道整个宇宙到底有多大，所以也就无法知道其中有多少原子。

If everything is made of atoms, do we know how many atoms there are in the universe?

For example, counting from the moment a person is born, there are about 78 billion atoms in an average human being (today's content, is full of all sorts of big numbers, so much so that I got tongue-tied when I read it to myself). Given that there are so many atoms in just one person, you might think it would be impossible to determine how many atoms there are in the entire universe. Actually, you're right, because we don't know exactly how big the entire universe is, and so there's no way to know how many atoms are in it.