Parshas Noach opens with the story of The Flood. The people who lived during Noah’s generation led immoral and deeply corrupt lives. They engaged in all kinds of illicit behavior. They stole mercilessly from one another. They stooped so low as to engage in theft petty enough not even to be worth taking to court!
G-d decided that this society would have to be destroyed and a new
civilization built in its place. He punished them by bringing The Flood (in 2105 B.C.E.)--a forty-day period of rain, destroying all vestiges of life from the face of the earth. Everything--men, women, children, animals, plants and trees--was destroyed. Almost the entire generation of humanity was wiped out. Only the righteous Noach and his family and at least one male and female of each animal species were left to repopulate the world, protected from the flood in a huge waterproof ark.
The floodwaters covered the earth for nearly a year. When the waters
receded, Noach sent out a bird to determine if the land was yet dry. The bird did not return, proving that there must have been dry land on which it could land. Noach and his family disembarked on Mt. Ararat (a mountain in current-day Turkey). G-d promised that He would never again destroy all of mankind by means of a flood. He told Noach that He would place a rainbow in the sky as a sign that He would never again destroy the world. Even today, when a rainbow appears, it means that mankind really deserves a flood, but G-d is holding back because of His promise. (Indeed, a special blessing is made when one sees a rainbow, thanking G-d for remembering His promise and keeping His word.) Other natural changes occurred following the flood. The year was divided into seasons (winter, spring, summer, and fall) and the human lifespan was shortened. G-d also permitted mankind to eat animal flesh.
Generations passed. The world was repopulated. Again, people distanced
themselves from G-d and worshipped idols. In time (1865 B.C.E.), they all joined together to build the great Tower of Babel, a structure intended to be so high that it would ascend to heaven, where man would wage war against the Creator. The Creator brought these plans to a halt by making people speak different languages. Suddenly, they were no longer able to communicate with one another! The Midrash says that when one person asked for bricks, he was brought cement, while another responded by hitting him on the head with an ax! Frustrations mounted with each passing day, understandably, and they had to give up building the tower. People scattered around the globe, setting up different countries and cultures, each with its own language. This generation is therefore referred to as the Generation of Dispersion.