The Sin of the Generation of the Flood symbolizes the world's drive to satisfy its base physical desires, while that of the Generation of the Tower of Babel represents spiritual rebellion and denial of God's rule in the world.
Hillel Nesi'a introduced the prozbul contract. The prozbul contract is a declaration by a creditor that he hands over all of his claims to the religious court and that he will collect these debts via the court’s authority after the Shmittah year.
In studying the ways of creation, we must remember that everything evolves from one ultimate source - the Torah. The Torah is the inner essence of all worldly matters. Creation is a mere manifestation - a reflection of the true essence, the Torah.
The Torah is the Universe's source. It is not like a blueprint that can be discarded once the construction is finished and the structure stands on its own; it is not like an idea that, after it has been actualize, can be forgotten.