Modern cosmology believes the universe to have come into existence about 15 billion years ago.

现代宇宙论认为 宇宙大约在150亿年前就已经开始形成了

When did the world come into existence?

世界是什么时候产生的？

When did this world come into existence?

这个世界是什么时候产生的？

But how did the dust itself come into existence?

但是尘埃本身又是如何形成的呢？

How did the universe first come into existence?

宇宙最初是怎么形成的？

When and how did the heavens and the earth come into existence?

天和地是什么时候怎样形成的呢？