crazy facts about the universe

The universe is overwhelmingly made up of things that cannot be seen. In fact, the stars, planets and galaxies that can be detected make up only 4 percent of the universe, according to astronomers. The other 96 percent is made up of substances that cannot be seen or easily comprehended. These elusive substances, called dark energy and dark matter, have not been detected, but astronomers base their existence on the gravitational influence that both exert on normal matter, the parts of the universe that can be seen.

The idea that we live in a multiverse, in which our universe is one of many, comes from a theory called eternal inflation, which suggests that shortly after the Big Bang, spacetime expanded at different rates in different places. According to the theory, this gave rise to bubble universes that could function with their own separate laws of physics. The concept is controversial and had been purely hypothetical until recent studies searched for physical markers of the multiverse theory in the cosmic microwave background, which is a relic of the Big Bang that pervades our universe.