Brian Keating

What limits the spread of consciousness through the universe? Rather than beginning with the origin of life or the probability of extraterrestrial intelligence, I will ask a more physical question: once life capable of evolving intelligence exists, what constrains its expansion in space, time, and complexity? Using Earth and Mars as a worked example, I develop a Drake-equation-like framework for the propagation of life and the growth of biological and technological intelligence. The calculation separates key bottlenecks: transfer between worlds, survival, habitability, evolutionary timescales, energy, communication delays, and the finite speed at which organisms, machines, minds or information can propagate. More broadly, what fraction of the accessible universe could consciousness ultimately occupy, and which limits are fundamental rather than merely technological?

Brian Gregory Keating is an American cosmologist. He works on observations of the cosmic microwave background, leading the POLARBEAR2 and Simons Array experiments. He also conceived the first BICEP experiment. He received his PhD in 2000, and has been a distinguished professor of physics at the University of California, San Diego since 2019. He is the author of two books, Losing The Nobel Prize and Into the Impossible.