Where does the Universe end? Or, to put it differently, does the Universe have an edge? When cosmologists say that the Universe is expanding, people tend to think of an exploding bomb. They see galaxies as shrapnel, flying off in all directions. Even if intuitive, this image is dead wrong.
The cosmic expansion is an expansion of space itself. Since Einstein's theory of general relativity, space has been endowed with a plasticity that allows it to expand, shrink or fold like a rubber balloon in response to the presence of matter (and energy).
Jazz multi-instrumentalist Sam Rivers, who died at 88 in December 2011, recorded with many trios in the 1970s. But his most celebrated trio was barely recorded at all. In 2007, it played a reunion concert — its first in 26 years.
We just talked about the changing demographics in this country. In fact, the Pew Research Center says Latinos will make up more than a quarter of the U.S. population by the year 2050. So we talked about how that might affect our public schools, but there's another group that's paying very close attention to these changes, and that's librarians.
This is TELL ME MORE from NPR News. I'm Celeste Headlee. Michel Martin is away. On television and in movies, the emergency rooms of big city hospitals are places of high drama, with doctors working furiously to save gunshot victims, those hurt in car accidents and people who are suffering a medical crisis, like a heart attack.
And now it's time for our regular feature, called In Your Ear. It's where we ask some of our guests to share their personal playlists with us. Zach Wahls made headlines when he stood before Iowa lawmakers urging them not to pass a constitutional amendment banning gay marriage. Wahl spoke up because his parents are lesbians. He stopped by our studios earlier this year to discusses his book, "My Two Moms: Lessons of Love, Strength and What Makes a Family." And he also took the time out to share some of the songs he loves to hear.
This is TELL ME MORE from NPR News. I'm Celeste Headlee. Michel Martin is away. Coming up, it's been nearly 60 years since public schools were legally desegregated, but new research shows schools are still divided. That's in just a few minutes.
This is TELL ME MORE from NPR News. I'm Celeste Headlee. Michel Martin is away. Coming up, a new documentary follows a harrowing day in an Oakland, California emergency room, where the policy questions about health care play out in real life. We talk with the director of "The Waiting Room." That's in just a few minutes.