The Universe is Expanding!
HOST INTRO: Here in New York, it’s hard to see stars in the sky, especially the stars that are really, really far away–the ones in distant galaxies. And someday, we may not be able to see them at all. That’s according to new research from the University of Michigan. Maggie Green explains.
GREEN 1: It’s 7 p.m. in Greenwich, Connecticut. Constellations speckle the sky from horizon to horizon. It’s freezing, and almost pitch black inside the Bowman observatory. A woman with long blonde hair peers through the giant telescope at the Seven Sisters star cluster.
It almost looks like tiny pinholes with lights in them.
GREEN 2: Beyond that lens, the universe opens up. Galaxies, nebulae, and star clusters focus into view.
GREEN 3: Ever since the Big Bang—almost 14 billion years ago—the universe has been expanding. That means that every galaxy is pulling away from every other galaxy. Astronomers don’t really know why the universe is pulling apart or why pulls apart faster when you move further from Earth. But they’re trying to figure it out. A new study accepted in Physical Review Letters demonstrates a piece of this mathematical puzzle. Dragan Huterer is one of the authors on the study.
Imagine you’re an ant living on a balloon, and the balloon is your world, the surface of the balloon, and that world, you know, someone is blowing up the balloon, so balloon is expanding.
GREEN 4: As the balloon expands, the distance between you and any other point on the balloon will increase at the same rate. And eventually, as each point in the universe pulls further and further away from every other point, we’ll start to see fewer and fewer galaxies. Then, one day, the Milky Way will be totally alone in the universe.
For those of us who have a chance to be around hundred billion years from now, uh, the sky will be empty.
GREEN 5: The sky would be empty. For clarification, astronomers say we’ll still be able to see stars because the ones we can see are very close to us. But we wouldn’t be able to see anything outside of our galaxy, like the cigar galaxy, 12 million light years away. It’s actually shaped like a cigar. And it’s moving away from us at about 200 kilometers every second.
So why do cosmologists–people that study the farthest reaches of the universe–care about what’s happening billions of light years away?
Yeah, that’s a question I get sometimes. You know, why do you do cosmology? Why do you study? It doesn’t have any immediate implications. We studied to learn more about the place we live in, which is the universe.
GREEN 6: It’s our innate curiosity that drives cosmologists to ask these big questions: where do we come from, and where are we going? And the more we learn about this puzzle, the more complicated it becomes. But that just makes room for the next group of astrophysicists to start asking those same questions, and start finding answers.
GREEN 7: At Columbia University, a few dozen people gathered on a Friday evening to learn about the way light travels through the universe. Cosmologists can use bright objects, like supernovae, to determine how fast the universe is expanding.
((Rose and Connor))
GREEN 8: Connor Golsong sat on the edge of his seat throughout the lecture, and then raced to the podium to ask questions at the end. He’s 12 years old, red hair and freckles. And he already knows he wants to be an astrophysicist. He says space exploration is inevitable…
It’s not a question of if, it’s a question of when. Humans have a drive to explore, to discover, to find new things. It’s in our nature. Ever since the first apes on the planet learned to walk upright and use spears.
GREEN 9: And if anyone is recruiting explorers to travel to distant galaxies….
Sign me up captain.
GREEN 10: It’s easy to see where Golsong gets his enthusiasm when you see the cigar galaxy as a sliver of light in the Bowman Observatory’s telescope. Every bit of light is millions, maybe even billions of years old. When we look at the stars, we’re really looking back in time. Cosmologists like Huterer are trying to look forward and predict how this night sky in Connecticut will look a few billion years from now. Golsong says whatever happens, he’s sure it’ll be…
Something unimaginable. Something amazing.
GREEN 11: And he hopes he’ll be the one to figure it out. Maggie Green, Columbia Radio News.
(Featured photo by Rick Bria, Greenwich Astronomical Society)