According to a new study by David Garofalo, an associate professor of physics at Kennesaw State University in Georgia, the existence of advanced life in the universe may depend on the influence of black holes on star formation.
The study, titled “Advanced Life Peaked Billions of Years Ago According to Black Holes“, will be published in the journal Galaxies and is available on the arXiv preprint server.
Garofalo argues that black holes can either drive or suppress star formation, depending on whether they are in gas-rich or gas-sparse environments. In gas-rich environments, black holes can create powerful jets and winds that blow away the gas and prevent new stars from forming.
In gas-sparse environments, black holes can spin faster and create more radiation that heats up the gas and triggers star formation.
The link between black holes and star formation has implications for the emergence of extraterrestrial intelligences (ETIs), which require billions of years of evolution and stable planetary systems.
Garofalo claims that “advanced life peaked billions of years ago”, when the universe was more gas-rich and black holes were more likely to suppress star formation. This would create a window of opportunity for ETIs to arise in galaxies that had enough stars but not too many.
Garofalo suggests that “we, as advanced life, might be relics from a bygone age” in the universe, and that we may have missed the party when most ETIs existed.
He also challenges the assumptions behind SETI, the Drake Equation, and the Fermi Paradox, which are based on the idea that individual planets are the key to finding life.
He proposes that we should look for galaxies that have the right balance between black hole feedback and star formation, and that we should consider the possibility that ETIs may have gone extinct or transcended their physical forms.
The study is based on theoretical models and observations of black holes and galaxies, and it raises many questions and uncertainties. For example, how do we define advanced life?
How do we measure black hole feedback and star formation? How do we account for other factors that affect habitability, such as supernovae, cosmic rays, and planetary dynamics? How do we test the predictions of the study empirically?
Garofalo acknowledges that his study is speculative and provocative, but he hopes that it will stimulate more research and discussion on the role of black holes in the evolution of life in the universe.