What should I do if there are no angels, or if I have never seen an angel but want to see one? Then build one. But what would a real angel think? Human beings, are you thinking too much? This is actually just the obsession of a bitter old man. This obsession both harms and helps the protagonist. So are there any angels? Are artificial angels successful? What happens to the selfish scientist and the innocent experimenter? It's written in the text, I'm not lying to you…