An unexpected twist: Spanish scientists propose a controversial new theory about the origin of the universe.

Where we come from and where we're going—these are some of the most frequently asked questions among human beings. Despite all the technological advances and constant scientific discoveries, the truth is that, with aspects such as the origin of our planet Earth, not all questions have yet been answered.

For many years, the dominant explanation in cosmology has been the inflationary model , which proposes that the Universe underwent an extremely rapid expansion in a tiny fraction of a second , also known as the "Big Bang".

While this theory has helped explain numerous aspects of why the world is the way it is, the truth is that this idea is only possible based on speculative or unproven assumptions . This doesn't mean that this theory is false, but rather that its veracity has not yet been 100% proven , something that is the case in most sciences.

But that leaves room for new hypotheses, such as that of a group of ICREA researchers at the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), in collaboration with the University of Padua (Italy), led by Raúl Jiménez, who have proposed a revolutionary new theory about the origin of the Universe.

Their study, published in Physical Review Research , represents a significant shift in how scientists understand the first moments after the Big Bang, and as we said, stands out because it avoids relying on speculative or unproven assumptions.

Their theory suggests that the universe began with a cosmic state called de Sitter space , which is consistent with actual observations of dark energy. These suggest that natural quantum fluctuations in space-time and gravitational waves were enough to seed the tiny density differences that eventually gave rise to galaxies, stars, and planets.

These ripples evolve nonlinearly, interacting and generating complexity over time, allowing for verifiable predictions with real data. "For decades, we have tried to understand the earliest moments of the Universe using models based on elements we have never observed," says Raúl Jiménez.

"What makes this proposal groundbreaking is its simplicity and verifiability. We're not adding speculative elements, but rather demonstrating that gravity and quantum mechanics may be sufficient to explain how the structure of the cosmos emerged."

These new results suggest that we may not need speculative elements to explain the cosmos, but only a deep understanding of gravity and quantum physics. If the model is confirmed, it could mark a new chapter in the way we think about the birth of the Universe.