Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe

by Brian Greene

building up complex atoms is an intricate process that requires time. It requires a highly specific series of steps in which prescribed numbers of protons and neutrons are melded together into various lumps, which then need to fortuitously encounter particular complementary lumps, fuse with them too, and so on. Like a gourmet’s recipe, the order in which the ingredients are combined is essential. And what makes the process particularly tricky is that some intermediate lumps are unstable, meaning that after they form they tend to disintegrate quickly, disrupting the culinary preparations and slowing atomic synthesis. This hindrance is a big deal because the steadily falling temperature and density as the early universe rapidly expands implies that the window of opportunity for fusion quickly closes. By roughly ten minutes after creation, the temperature and density drop below the threshold required for nuclear processes.10