In this week’s Cosmically Curious, Patrick McNameeKing talks with Nicole Gugliucci of Saint Anselm College about the cosmic microwave background — a faint glow that fills the sky and offers clues about the universe’s beginnings.
Transcript:
Patrick McNameeKing: In previous episode, we talked about a microwave oven that threw astronomers for a loop.
But Nicole, you said there's something else unrelated, and it's called the cosmic microwave background. What is it?
Nicole Gugliucci: It's this glow that is seen all around the sky. So it's "cosmic" because it's coming from everywhere and it's "microwave" because that's the frequency and it's "background," because it's literally the background of everything.
Patrick McNameeKing: So what's the backstory?
Nicole Gugliucci: This was first discovered sort of by accident by a couple of astronomers at Bell Labs in New Jersey.
They were trying to get their radio telescope to the most sensitive ever and point it at a blank part of the sky and get like nothing. Except they kept getting a signal no matter where they pointed.
This was a horn-shaped telescope, and it's still there (and I think they're actually turning it into a little monument). It was a horn-shaped telescope — and pigeons would roost in it. They actually had to go out and scrape the pigeon poop out because they thought the pigeon poop was causing the signal.
They were two astronomers named Arno Penzias and Robert Wilson. And they couldn't figure this out. And they called some of their colleagues down the road who were working on these cosmological models of the universe and the Big Bang.
According to those models, they predicted there would be this background light at around that level, at that frequency. And they were trying to think of ways to discover it. And they get a call from their colleagues down the way and say, "hey, we discovered this thing." And Penzias and Wilson ended up getting the Nobel Prize for that discovery because they didn't give up.
They saw a signal they didn't understand and they didn't give up, which is really awesome.
Patrick McNameeKing: Thanks, Nicole. Next week, we'll learn more about what that strange glow actually is.
If you have questions about the night sky, send us an email at Cosmic@nhpr.org.
