1. Brahma’s dream – hindou mythology
For hindus, time has no beginning nor end. It is built in cycles. At the end of one’s life, one reincarnates itself in another life. And their way of seeing the universe is cyclical as well : right where it ends, the universe starts all over again.
According to hindu mythology, when Brahma (the hindu god) falls asleep, a universe is created. When he wakes, this universe disappears. It is the same universe, that comes to life and dies again and again, every time Brahma dreams.

Excerpt from “Le monde hindou”, in “Mondes : Mythes et Images de l’univers”, by Leïla Haddad & Guillaume Duprat, pub. Seuil, 2006

The terrestrial continent lies around Mount Meru, which is at the center.
Every circle around represents a sea : an ocean of salty water, a sugar-cane sea, a sea of wine, a sea of butter, a sea of sour-milk, a sea of milk, and a sea of fresh water.
2. The Stoics – greek philosophers
According to antiquity’s Stoics, our world is a world among a series of worlds that exist one after the other.
In between two of those worlds, an explosion occurs, in which one world disappears and the following appears.
3. The Big Bang and the Big Crunch – current theories
- The Big Bang :the universe grew out of a terrifying explosion about 15 billion years ago. It has been expanding ever since : the energy released by the explosion’s blast stretches space out more and more, continuously.
- The maximal expansion phase : the universe stretches out no longer.
- Contraction : the expansion is reversed, and contraction begins, shrinking the universe in and onto itself, and smashing particles into one another.
- The Big Crunch : as the contraction occurs and progresses, the universe heats up and densifies, till a reversed Big Bang occurs, “the Big Crunch”.
- A new Big Bang occurs, and the universe bounces back. A new universe in expansion is createdout of the blast of the Big Crunch.

Image taken from the european spacecraft Planck : The universe, 380 000 years after the Big Bang. At the time, its size is close to that of a grapefruit.
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