The author invokes Italo Calvino’s image of the universe as a mirror to frame a new study showing galaxies are cooling and star formation is declining. Scientists used ESA telescope data to measure dust masses and temperatures in over 2 million galaxies and conclude that the peak of star birth was about 10 billion years ago. Co-author Douglas Scott warns the cosmos "will just get colder and deader from now on," but the piece emphasizes that the universe — and human curiosity — still have vast stretches of time ahead.
The Universe Is a Mirror — and It’s Growing Colder: Galaxies Are Cooling as Star Formation Slows
The author invokes Italo Calvino’s image of the universe as a mirror to frame a new study showing galaxies are cooling and star formation is declining. Scientists used ESA telescope data to measure dust masses and temperatures in over 2 million galaxies and conclude that the peak of star birth was about 10 billion years ago. Co-author Douglas Scott warns the cosmos "will just get colder and deader from now on," but the piece emphasizes that the universe — and human curiosity — still have vast stretches of time ahead.
07:30 AM, 11/13/2025Science
Italo Calvino anticipated this mood decades ago. In 1985’s Mr. Palomar he wrote, “The universe is a mirror, in which we can contemplate only what we have learned to know in ourselves.” That image feels especially apt in light of new cosmic measurements.
This week, researchers using data from two European Space Agency (ESA) telescopes reported that galaxies are cooling and the pace of star formation is slowing. The team analyzed dust masses and temperatures in more than 2 million galaxies to build one of the most complete maps of the cosmos to date. Their analysis suggests the universe’s peak era of star birth occurred roughly 10 billion years ago — a prime now firmly in the rearview.
The results appear in a preprint submitted to Astronomy and Astrophysics. The study focused on the volume and temperature of interstellar dust, a key tracer of star-forming activity: dust both absorbs starlight and re-radiates it in the infrared, so cooler dust and declining dust mass generally signal falling rates of new-star formation.
“The Universe will just get colder and deader from now on,” said University of British Columbia cosmologist and co-author Douglas Scott. “The amount of dust in galaxies and their dust temperatures have been decreasing for billions of years, which means we’re past the epoch of maximum star formation.”
That may sound bleak, but it’s not an immediate extinction event. While the production of new stars is ebbing, many stars — including long-lived, low-mass stars like our Sun’s smaller cousins — will continue to shine for billions to trillions of years. The authors and other cosmologists note wildly different timescales for the far future depending on which processes dominate: conservative estimates put major stellar evolution changes on the order of tens of billions of years, while theoretical limits for the very distant future can extend to fantastically large numbers (the paper cites figures ranging from about 33 billion years to as large as 1 quivigintillion years, depending on the metric and assumptions used).
Put another way: the universe is aging on cosmic timescales, but it will remain vast, varied, and — for a very long time — observable. For humans, and for curious writers taking comfort from Calvino’s mirror, there’s still plenty of spacetime to explore and appreciate.
Read more: “Before There Were Stars”
Originally featured on Nautilus.