One of the mysteries of the universe is why it expands at the rate that it does. Back in 1998, two teams of researchers observed that not only was the universe expanding, but that the rate of expansion was increasing. That observation was the basis for a concept now known as dark energy. In the years since, cosmologists have been trying to get a handle on better measurements of that effect, and hoping to figure out what dark energy actually might be.
This week, researchers on a project called DESI, the Dark Energy Spectroscopic Instrument, released results based on their first three years of data at an international physics conference. They found that it appears possible that dark energy—whatever it is—has changed over the lifetime of the universe. In other words, the so-called cosmological constant may not, in fact, be a constant. The data is not quite statistically significant yet, so researchers can’t definitively say that this is true, which leaves many questions about the nature of dark energy still unresolved.
Dr. Andrei Cuceu of the Lawrence Berkeley National Laboratory and Dr. Adam Riess of Johns Hopkins University and the Space Telescope Science Institute join Host Flora Lichtman to talk about the new research, and what remains to be discovered in dark energy.
Further Reading
- Read more coverage of the latest findings based on DESI data via NPR.
- Learn more about DESI’s work.
- Watch our Book Club chat with the author of The End of Everything (Astrophysically Speaking), about a few ways the universe might actually, realistically end.
Segment Guests
Andrei Cuceu
Dr. Andrei Cuceu is a postdoctoral research fellow at Lawrence Berkeley National Laboratory in Berkeley, California.
Adam Riess
Dr. Adam Riess is a 2011 Nobel Laureate in Physics, is Bloomberg Distinguished Professor at Johns Hopkins University and the Space Telescope Science Institute in Baltimore, Maryland.
Segment Transcript
The transcript of this segment is being processed. It will be available early next week.
Meet the Producers and Host
About Charles Bergquist
As Science Friday’s director and senior producer, Charles Bergquist channels the chaos of a live production studio into something sounding like a radio program. Favorite topics include planetary sciences, chemistry, materials, and shiny things with blinking lights.
About Flora Lichtman
Flora Lichtman is a host of Science Friday. In a previous life, she lived on a research ship where apertivi were served on the top deck, hoisted there via pulley by the ship’s chef.