I think it's really stupid how everyone complains about sentences being "weird" or that they have no idea "how they could use it". The point of learning a language is to actually know it and be able to understand what is being said instead of just memorizing sentence after sentence.
While this is a good point I feel like there's a pedagogical difference between phantasy sentences that are weird and sentences like this where you are left wondering if it's just a random word jumble that maybe wasn't translated correctly and you have to memorise the duolingo form of it...
Yes. In particular, if you're describing something as the most (adjective) thing in the world, the phrase "на свете" is often used for "in the world". For example, "Лучшая пицца на свете!" means "Best pizza in the world!" You can see more in the second definition listed here: https://en.wiktionary.org/wiki/%D1%81%D0%B2%D0%B5%D1%82#Russian
This may allude to the greek myth of the theft by Prometheus of fire from the gods. Fire symbolised life (and light). It's about Zeus, Mt Olympus ... look it up!
Another narrative is of when photo synthesising algae caused Earth's atmosphere to get a much higher proportion of oxygen. Some 2+ billion years ago. Life as we know it evolved (in parallel) since. You can look that story up, too!