Dr. Alan Dressler discusses the James Webb Space Telescope and its ability to see galaxies in the throes of birth 13 billion years ago. The telescope takes pictures of galaxies with extreme sensitivity to infrared light, allowing astronomers to explore the earliest moments of the universe. The team found that galaxies were born with explosive bursts of star formation, unlike anything seen before. New episodes of Looking Up release every other Friday!
Additional resources referenced in this episode:
- Early Universe Crackled With Bursts of Star Formation, Webb Shows
- Infrared: More Than Your Eyes Can See
- AAS 242 Press Conference: Discoveries in Distant Galaxies
EPISODE TRANSCRIPT:
Looking Up is transcribed using a combination of AI speech recognition and human editors. It may contain errors. Please check the corresponding audio before quoting in print.
Dean Regas: [00:00:00] You are made of stardust. No, seriously. You really are made completely out of stardust. Your body, your emotions. Okay? Your memories, your hopes and dreams are the culmination of billions of years of expansion from a single point. Teeny tiny speck of light and energy that exploded atoms and molecules flung outwards into existence.
No, look at you. Oh, I wonder what you, here you are. That was great. Way to go and, okay, sure. And we've all heard this idea, right, of the big bang, but what if we could actually see it in action, the beginning of the universe, the earliest. Hearts. Today we're joined by an astronomer whose team caught a glimpse of the early little baby, cute [00:01:00] universe using the James Webb Space Telescope from the studios of Cincinnati Public Radio.
I'm your host, Dean Regas, and this is looking up.
The show that takes you deep into the cosmos or just to the telescope in your backyard to learn more about what makes this amazing universe of ours, so great. Our guest this week is Dr. Allen Dressler, astronomer at the Carnegie Institute for Science and Collaborating Scientist on the Jades Project.
So the big superstar in the telescope world has to be the James Webb Space Telescope. This was designed to study a lot of different things, but galaxies seem to be the hot topic recently. So the idea is when you look through a telescope, you're looking in space, you're making things that are really, really far away, look a lot closer.
That's just what telescopes do, but what the web telescope [00:02:00] does. Better than others is that it can also look in different wavelengths of light. The world looks a lot different in infrared light. Remember that what you're actually seeing is temperature. So something that's warm is gonna look bright in the infrared, so it sees things that the eye can't see.
It sees light in the infrared. It can often pass through things that block visible light entirely. You can make sensors on telescopes even more. Accurate and even more sensitive if you can look in this wavelength of light, and that's what makes James Webb so much better is that it can see these things that are farther and farther away.
If everyday objects look different through an infrared camera, you can bet objects in space too, too. I, I know this is maybe too early in the show to get deep, but you guys ready to get deep on this because there's some reality problems here. I just have to take a deep breath because when you look in space, you are not looking at how things are.
You're looking at how things were. So for [00:03:00] example, it takes, the sun, takes about eight minutes for the light from the sun to go from the sun to us. So that means when you see the sun, you're seeing light that's eight minutes old. You're seeing where the sun was eight minutes ago. Oh man, this is gonna get deeper really fast because when you look at the stars, that's where they were years ago.
It takes years for the light to travel from those stars to us. And so when we look at galaxies, we're looking at galaxies that are millions to billions of light years away. I know this is like, wait a second. Am I in the matrix or something? The standard models and, and the evidence from various sources are pointing to a universe that started about 13.8 billion years ago.
So if we could look back the 13.8 billion light years in space, we can look back to the beginning. It sounds easy, right? Yeah. Piece of cake. Just build big telescope and look out in space. Well, no. James, we, space Telescope has a team survey. Jades, jades, [00:04:00] jades Space Telescope, so it stands for the James Webb, that's the J part, advanced deep, extra-galactic survey.
This is a program that's gonna like look at the really, really far away stuff for about 32 days and try to see the faintest of the galaxies that are out there. So the idea is if we see the earliest galaxies, we can get a glimpse as to how later galaxies may be formed. And I gotta tell you the newest ones that we're finding, the earliest youngest galaxies are real weird, I can't wait to talk to our guest to find out what we are uncovering right now. Hello. Good afternoon.
Dr. Alan Dressler: Hi. Is that Dean?
Dean Regas: It is Alan, thanks so much for joining me today.
Dr. Alan Dressler: My pleasure.
Dean Regas: We're really excited to be joined by our special guest, Dr. Alan Dressler, who's the astronomer at the Carnegie Institution for Science and the collaborating scientist on the Jades Project.
This has to be like amazing to be seeing the James Webb Space Telescope. Get up [00:05:00] there, start doing this amazing science. And studying galaxies. How are you feeling so far with the accomplishments of J W S T to date and what are you looking forward to?
Dr. Alan Dressler: It's pretty indescribable and this, this took so long to build and was so difficult and so, you know, so sort of perilous to launch and that to actually had it worked and working this well.
I think everybody who was involved. Is well just overwhelmed by what we actually accomplished in this.
Dean Regas: Well, speaking of the, you know, kind of the deep field and early universe, you're working on the, the Jades program. And so this is gonna be devoting, you know, about a month of telescope, time to check out and. characterize these faint distant galaxies. Yeah. Tell us what, what the, this project is hoping to do and why Look at old young, wait. Old galaxies or young galaxies? Young [00:06:00] galaxies.
Dr. Alan Dressler: They're young galaxies. Yes.
Well, the, the two teams that make up Jades were the team that built the camera, takes pictures of the sky and the team that built up the spectrograph, which is mostly based in Europe. Which takes the light from individual galaxies. In fact, it could take many at a time and splits it into his colors for, let's say a astrophysics sort of analysis.
We'll finally be able to see more than our eyes can see. The teams are actually doing many kinds of science, but part of the two teams that we're going to do work on distant galaxies decided to pool their time because they had two different views with the pictures. And the spectra and they thought they might as well work together.
So each team got a certain number of hours, sort of hundreds of hours of, of, of time on James Webb in return for the many, many years that they spent developing these two instruments. There's a [00:07:00] whole range of studies going on, but as you mentioned, the key thing here, Is that when astronomers look out into space, they're looking back in time.
And with the Hubble Space Telescope, which was launched in the in the nineties, we've learned that we could get back pretty far in the history of the universe, which means pretty far out of 14 billion years.
So out of that 14 billion years, the Hubble sort of took us maybe 10 or 11 billion years back in time. And from that we learned that it was gonna do better than we thought it was gonna get us closer to when galaxies actually were born. And that was the impetus for building the James Webspace telescope.
I had the the honor of chairing a committee at that time in the, in the mid nineties that would made that [00:08:00] recommendation to NASA and said exactly that, that. We needed to go into the infrared in order to get the sensitivity in order to get to the birth of the first galaxies, and that, that would be extremely rewarding kind of thing to do.
And something that, you know, a civilization like ours only gets to do once to see back to the very beginning.
Dean Regas: So, yeah. What, what is your, your role and the primary focus with the JADES project?
Dr. Alan Dressler: So my focus was what, in fact, that committee identified as the kind of prime mission of the telescope, which was to see galaxies in their infancy.
I've been working on that for about five years, getting ready to make these observations, and they come from looking at very, very deep. Pictures, as you said, those pictures are made in many colors, seven different bands of color. However, it's infrared colors, nothing we could see. You can use [00:09:00] the brightness of these very, very faint dissing galaxies to figure out how many stars they have made and over what period of time.
In other words, it's like you're mapping the growth of your child on the, on the back of the door with credit on over. How old are you? Three. Okay. And you're watching it grow. And that's what we're doing. We're watching the galaxies grow from near nothing to billions of times. The mass of the sun.
Yes. Galaxies grow by birthing new stars, generations of stars. That's how they take the gas that's in the galaxy and turn it into stars like the sun which then through their lifetimes build up. Heavy chemical elements, carbon, nitrogen, oxygen, iron, all those things in their cores, and none of that heavy element.
Part of the universe was there before stars and galaxies came along. And the, the thing that's so [00:10:00] amazing is that if that hadn't happened, the universe would've just fizzled. But everything you see around you from the earth to your friends, everybody is made up of those heavy chemical elements that changed the nature of the universe.
Dean Regas: Well, I think you hit upon a, a, a little misconception that I think most people have about. Know, the, the beginning of the universe, the Big Bang, you get this kind of animation and I dunno, maybe we got it from a certain TV show of that certain name, but like that when the Big Bang happened, galaxies preformed are already there flying out of this beam of light. And so, oh, that's, that's not correct. Right. You know, like when the Big Bang happened. What, what happened before Galaxies formed? There was a lot of time before that, correct?
Dr. Alan Dressler: Yes. It took about 400 million years before things cooled down enough. I mean, the Big Bang was extraordinarily hot to hot for a [00:11:00] human being to sort of measure it.
And as it expanded, it cooled. That's kind of a, a natural physics phenomenon. But it took a long time before the matter that it was generated in the Big Bang could get cold enough. It was already sort of a little clumpy in places, but those clumps began to collapse by gravity.
Gravity pulled the denser parts together and emptied out the less dense parts, and so we started to get structures that would become galaxies. And that happened, as I said, sort of a few hundred million years after the Big Bang. Now that's compared to 14 billion years today. So it's pretty early, but it's certainly nothing like, you know, right near the Big Bang that that world was so different from ours.
So alien in a sense that all the things we recognize as being in the universe could never have been because it was so hot. So [00:12:00] it was made of particles. We don't even see around today.
Dean Regas: Well, and so that's what we're, we're looking for with the, with James Webb is, you know, getting as far back as possible. Is there, you know, what, I guess what is the, the youngest galaxy we've seen and is there a limit then? Is there, you know, you're expecting like, okay, we're not gonna see anything past this point.
Is that, is that-
Dr. Alan Dressler: Yeah, that's right. And we have pushed back what we see to about 300 billion years with. The James Webb, that particular observation is of something that is so little light coming out of it that although we're certain that we've got it right, there's not much more we could say about it, but I'm starting a little bit later than that. And look at galaxies that are four or 500 million years to start with. And then going to about a billion, which is another 500 million years. And over [00:13:00] that period of time, a lot happens. Those little specks of light begin to grow.
And the thing that has turned out to be a big surprise is that they didn't grow sort of gradually. That's the way we see galaxies. Growing today is quite gradually this kind of star formation was not jet and continuous, but really bursty. There were great sort of immense bursts of star formation and billions of solar basses were created in less than a hundred BA years.
Which was fast and that's really surprising. We don't see anything before those bursts. It's not like they were kind of building up to it. Boom, it just takes off and we get a a lot of mass so that we [00:14:00] really have an infant galaxy and that actually most of them shut down. We know they have to grow much more to be the galaxies of today, and they will.
How to make that transition from being a sort of an almost explosion of star formation, to be a quiet building, we don't know.
And so the question is, We have physicists and people who make models in computers of how galaxies grow, and they didn't predict this, so they have to go back to the drawing boards and see if they can understand how this could actually take place.
Dean Regas: Well, and this is just the beginning. We're just a few years into James Webb and you know, this has to be so exciting to look back at the earliest parts of the universe. And hopefully we're just beginning. I hope there's a lot more to come for you. As we say around here, we wish you clear skies, but for James Webb, you don't. You always have clear skies, don't you?
Dr. Alan Dressler: Well, you need to [00:15:00] hope that this very complex telescope, which is, you know, a million miles away and under complete remote control, It survives. We, we think we could get 20 years of life out of it. And you're absolutely right that in 20 years it will revolutionize astronomy.
Dean Regas: It, it's so fascinating and we'll be watching this carefully just to be part of this project. It has to be awesome. And we appreciate you taking the time. This has been so fun talking with you, Alan. I really appreciate it.
Dr. Alan Dressler: Thank you very much. And look, hello to everybody at Cincinnati.
Dean Regas: That's right. Our Cincinnatian! Anytime you're in the area and your old stomping grounds, stop on by and say hi. Would love to have you.
Yeah, well I could maybe set something up for another year and I probably have a lot more to tell you. That would be awesome. That would be awesome. Thank you.
Dr. Alan Dressler: Thank you. Thanks. Take care guys. .
Dean Regas: Well, so what's next for the James Webb Space Telescope? I had no idea, man. They are like keeping their secrets. Looking up with Dean Regas is a production of Cincinnati Public Radio. Marshall Verbsky [00:16:00] is our show producer and galactic expansion specialist. And Marshall, the universe is expanding, so your realm keeps getting bigger.
Ella Rowen is our audio engineer and purveyor of Universal Truth. And you know Ella, the truth is out there. Our theme song is Possible Light by Ziv Moran. I'm Dean Regas and keep looking up, man. I can use all these whispery voices when I talk about the galaxies.
