A formula for life? New model calculates odds of intelligent beings in our cosmos and beyond

The odds of intelligent life emerging in our cosmos—and in any hypothetical ones beyond it—can be estimated by a fresh theoretical model which has echoes of the celebrated Drake Equation. This was the formula that Dr. Frank Drake, an American astronomer, came up with in the 1960s to calculate the number of detectable extraterrestrial civilizations in our own galaxy.

More than 60 years on, astrophysicists have produced a different model which focuses instead on the conditions created by the speeding up of the universe’s expansion and the amount of stars formed. It is believed the expansion of the universe is being driven by a mysterious force termed dark energy that makes up more than 2/3^rd of the cosmos.

What is the calculation?

Since stars are a prerequisite for the emergence of life as we know it, the model could hence be used to estimate the likelihood of generating intelligent life in our cosmos, and in a multiverse scenario of different hypothetical cosmoses. The new research doesn’t try to calculate the absolute number of observers (i.e. intelligent life) in the cosmos but instead considers the relative likelihood of a randomly selected observer inhabiting a cosmos with particular properties. Research concludes that an archetypal observer would expect to experience a considerably larger density of dark energy than is seen in our own cosmos—suggesting the ingredients it has make it an unusual and rare case in the multiverse.

This approach involves calculating the fraction of ordinary matter converted into stars over the whole history of the cosmos, for different dark energy densities. The model forecasts this fraction would be roughly 27% in a universe that is most competent at forming stars, compared to 23% in our own cosmos. This means we don’t reside in the hypothetical cosmos with the highest odds of forming intelligent life forms. Or in other words, the value of dark energy density we observe in our cosmos is not the one that would maximize the odds of life, according to the model.

Dark energy’s impact on our existence

Lead researcher Dr. Daniele Sorini (Durham University’s Institute for Computational Cosmology) said, “Understanding dark energy and the impact on our universe is one of the biggest challenges in cosmology and fundamental physics.” “The parameters that govern our universe, including the density of dark energy, could explain our own existence. Surprisingly, though, we found that even a significantly higher dark energy density would still be compatible with life, suggesting we may not live in the most likely of universes.”

The new model could let researchers to understand the effects of differing densities of dark energy on the formation of structures in the cosmos and the conditions for life to develop in the universe. Dark energy makes the cosmos expand faster, balancing gravity’s pull and creating a cosmos where both expansion and structure formation are probable. Nevertheless, for life to develop, there would need to be expanses where matter can clump together to form stars and planets, and it would need to remain stable for billions of years to let life to evolve.

Importantly, the research suggests that the astrophysics of star formation and the evolution of the large-scale structure of the cosmos combine in a subtle way to determine the optimal value of the dark energy density required for the generation of intelligent life. Professor Lucas Lombriser (Université de Genève and co-author of the study) added, “It will be exciting to employ the model to explore the emergence of life across different universes and see whether some fundamental questions we ask ourselves about our own universe must be reinterpreted.”