He comes down in a whirlwind and poses a number of rhetorical questions to Job, all of which are designed to show Job how small he is in relation to the universe...which, by the way, God created.
You should probably go back and check this part out. Some of the questions are pretty awesome.
God's wisdom isn't like human wisdom. After all, God is concerned with making waves flow and the architecture of the heavens. You know, big deal things.
This doesn't mean that human affairs don't concern him; they're just one part of a vast, unknowable whole.
Basically, Job's question is answered with a bunch of equally unanswerable question. He is completely and totally out of his league on this one.
Note to Shmoopers: God talks of natural things in human terms so that Job can understand them. By doing so, he illustrates how the mortal and the immortal are so far apart even though they are physically close together (see 38:28).
Oh, and by the way, a lot of these passages make their way into modern thought. Again, just go ahead and read it.