What existed in the universe before Earth?

In a groundbreaking study, researchers have proposed a new idea that challenges the traditional Big Bang theory of the origin of the universe. According to this new cosmological model, the universe may alternate between contracting and expanding phases.

This study suggests that dark matter could have been made of black holes during the transition from the contracting phase to the current expanding phase, which predates the Big Bang. If this theory holds true, these findings could be tested in the future by gravitational wave observatories, which would detect the waves produced during the formation of these black holes.

Dark matter makes up about 80 percent of all matter in the universe, and observations of the cosmic microwave background and the motion of galaxies support its existence. But despite these hints, the composition of dark matter remains a mystery.

The study provides insights into conditions in the universe before the Big Bang by examining a period when dark matter may have been dominated by primordial black holes, which were formed by density fluctuations during the universe’s final contraction.

In this “bounce” cosmological model, the universe could shrink to 50 orders of magnitude smaller than it is today. This contracting phase could also include dark matter and black holes that existed before the Big Bang.

Patrick Peter, a research director at the French National Center for Scientific Research (CNRS), who was not involved in the study but shared his insights with Live Science, explained that small primordial black holes could have formed very early in the history of the universe. Unless they were very small, they would not have completely decayed through Hawking radiation (a theoretical process by which black holes emit particles due to quantum effects) and would still be around today.

“These black holes, which have masses comparable to those of a small planet, could explain the existence of some dark matter and could even solve this long-standing mystery. Peter stressed the importance of this research, noting that it introduces a plausible mechanism to explain how small but persistent black holes could form dark matter, a mechanism that is different from the traditional inflation theory.”