美国国家公共电台 NPR--An astrophysicist breaks down what NASA's Webb telescope tells us about our universe（在线收听）

An astrophysicist breaks down what NASA's Webb telescope tells us about our universe

Transcript

NPR's Morning Edition speaks with astrophysicist Alex Filippenko of the University of California, Berkeley about the latest findings of the Webb Telescope.

RACHEL MARTIN, HOST:

So many of us are still in wonder this morning, scientists included, because of the new images taken by NASA's Webb telescope. It's brought mankind to the deepest corners of the universe. The extremely detailed pictures show stellar nurseries and individual stars. On the line with us this morning is University of California, Berkeley astrophysicist Alex Filippenko. He is so excited, he has agreed to join us in California to talk about the implications of all these images.

Good morning. Thank you so much for being with us, Professor.

ALEX FILIPPENKO: Well, good morning, Rachel. It's a true pleasure to be here because it's such an exciting time for astronomers and, I think, for the general public seeing all these fantastic images.

MARTIN: Yes. We personally made a rare exception at our family dinner table last night and allowed screens so we could show our kids these images. I imagine this also dominated dinner conversation at your house.

FILIPPENKO: Oh, wow. Well, you know, these are just incredible. So I think everyone is just aghast at what the quality is from the Webb telescope.

MARTIN: Right. They're so clear, the light so spectacular. Is there a particular image you found most revelatory?

FILIPPENKO: Well, I like the first one that they revealed on Monday because it shows these distant galaxies - thousands of them - in a patch of sky, no bigger than a grain of sand held at arm's length. And if you extrapolate over the whole sky, the implication is that there are between a hundred billion and a trillion galaxies in the observable part of our universe. And each of them has billions, if not hundreds of billions of stars. So those are pretty amazing numbers.

MARTIN: What clues do these images offer about the beginnings of the universe?

FILIPPENKO: Well, that's one of the main things that we hope to study with Webb with more detailed images of this type. We hope to see the very first stars and galaxies forming about 13 1/2 billion years ago, just a couple of hundred million years after the birth of the universe, the moment we call the Big Bang.

MARTIN: And explain how these pictures compare to images provided by Hubble, the older telescope.

FILIPPENKO: Right. So Hubble is a fantastic device, but it operates mostly at what we call visible or optical wavelengths - the wavelengths of light that you can see. The Webb telescope is tuned for the infrared. So that's commonly called heat radiation, like from hot coals in a fire. And what's great about the infrared is that it gives a complementary picture to what Hubble provides. And so looking, for example, at extremely distant galaxies, most of their ultraviolet and visible light gets shifted into the infrared because of the expansion of the universe. And so the only way to detect these infant galaxies and the first stars ever to have formed is to look at infrared wavelengths.

MARTIN: So we explained to our kids last night that this is significant - all these images - in part because we just keep learning how big the universe is. And my 10-year-old insists that because of this, there must be other life out there. Not to put you on the spot, but what is your answer to him?

FILIPPENKO: Well, yeah, there's almost certainly other life out there. Whether there's a lot of intelligent life is a different question. And I personally think it's quite rare. But we're likely not unique. So we will be looking for biosignatures in the atmospheres of planets orbiting other stars. That's one of the main exciting projects to be done with the Webb. And certainly, I'm looking forward to those results. Maybe we'll find that life is more common than some of us think.

MARTIN: Oh, I can't believe I almost interrupted that. But that's the most important part. Astrophysicist Alex Filippenko, thank you for your time this morning.

FILIPPENKO: It was a pleasure. Thank you.