It’s evening in the universe. The rate at which the universe is producing stars has fallen continuously in the last 11 billion years. The stars we have are dying, and we’re not making new ones the way we used to. A group of British and American astronomers recently reported that the birthrate of stars in the universe has declined precipitously and continuously over the last 11 billion years.
The universe today is only producing stars one-thirtieth as fast as it was at its peak in the lusty primordial days when protogalaxies, all gas and spume, were bouncing around like pups in a closet, colliding and merging, popping with blazing bright new stars.
In a news release issued by the Royal Astronomical Society, the astronomer David Sobral of Leiden University in the Netherlands said, “You might say that the universe has been suffering from a long, serious crisis: cosmic G.D.P. output is now only 3 percent of what it used to be at the peak in star production.” Dr. Sobral and his colleagues published their paper in the Monthly Notices of the Royal Astronomical Society.
They calculated that the current consolidation rate of “starstuff” into stars amounts to about a half a trillion tons per year per cubic light-year. The Sun is about 2,000 trillion trillion tons. In a fundamental sense, this cosmic fatigue is not really new. Other surveys, including one led by the aptly named Alan Heavens of the University of Edinburgh a few years ago, have come to similar conclusions. But one detail of this new study hit me.
Dr. Sobral and his colleagues said that if this decline in breeding goes on, it means the universe has already made 95 percent of the star mass that it will ever make. As eternity goes on — and on and on — the cosmos, like Palm Springs, will be dominated by older and older stars.