One of the big ideas to emerge in the last half-century is the notion that human beings — in fact, all biological life — originated in the stars.
Scientists studying the origins of life and the universe have theorized that the elements and molecules that form living beings were all forged from stars that lived and died before the Earth was born.
In his book The Stardust Revolution, science writer Jacob Berkowitz traces the development of this idea through history, from medieval alchemists trying to understand the properties of elements to astronomers observing the spectra of stars.
Berkowitz recounts the scientific discovery by astronomers that the most common elements within stars — hydrogen, carbon, oxygen and nitrogen — are also the same elements that comprise humans. "We are essentially an elemental reflection of the rest of the cosmos," he says.
This idea of a shared heritage between human beings and the universe puts a new spin on the search for alien life on other planets.
"When we discover other life on other living planets, we won't really be discovering alien beings," says Berkowitz. "We'll be discovering distant cosmic cousins, because we are all evolved from the same cosmic processes."
He says that understanding this process of how life evolved from stardust, the name for cosmic dust from the gases of stars, is the next major development in astroscience.
"The great cosmic story of the 21st century is … not about the expanding universe but about the evolving universe," says Berkowitz.