UC Santa Cruz astronomer Garth Illingworth, former deputy director of the Space Telescope Science Institute, has had an incredible career.
He spent decades researching and understanding more distant galaxies and was a leader of the team that built the Hubble Space Telescope. And before Hubble was even in the sky, he had already started developing the James Webb Space Telescope (JWST) – yes, That James Webb Space Telescope, the one that currently blasts the minds of earthlings every day with incredibly beautiful images of our universe.
While most of us look at those JWST images and only see images, Illingworth and his colleagues see all that and more – the data. Over the course of its few months of operation, Webb has already offered an illuminating breadth of information, discoveries that have confirmed, confused and even contradicted existing theories about the cosmos. Curious to know what those data mean ourselves, we caught up with Illingworth to talk about space telescopes, distant worlds and the ever-changing scientific process.
This interview has been edited and condensed for length and clarity.
Futurism: Your work has been extensive. Can you tell us a little about your research and where did it lead you?
Garth Illingworth: Sure, I’ll give you the scientific picture. I am an astronomer and my main interests were the first galaxies in the universe. Basically, we live 13.8 billion years after the Big Bang in a large, wonderful spiral galaxy, the Milky Way. But we had to get to this point.
The beginnings have intrigued me for a long time, since I saw Hubble Deep Field in 1995, Hubble’s first deep image of an empty part of the sky, which turned out not to be empty, but absolutely filled with galaxies. This is what I have been working on for 25 years or so. Actually, in the 1980s, when I started thinking about Webb, we hadn’t even launched Hubble. Riccardo Giacconi, then director of the Space Telescope Science Institute, told me: “You guys really need to work on the next big telescope. Trust me, it will take a long time.”
At that point we had to do something pretty interesting. We had to project forward, even when we didn’t know what Hubble was going to find. We realized we should go to longer wavelengths, we really should go infrared – we felt there were so many ways this could reveal aspects of the universe that Hubble would never reveal. It had to be a large telescope to work in the infrared. It must have been really cold, which meant it had to be a long way from here. When we look back at the designs now, these very simple designs, it is completely different from Webb, but actually Webb works and has the features we thought of back then. It’s a big telescope, it’s infrared, it’s really cold, it’s very far from us [laughs].
Correct me if I’m wrong, but you and your team have discovered what is believed to be the most distant and ancient galaxy humans have ever seen, dating back approximately 400 million years after the Big Bang.
Yes. So, about seven or eight years ago, using Hubble, we surprisingly found an object that was about 400 million, 450 million years after the Big Bang. I think if you had asked me 10 years ago if Hubble would do that, I wouldn’t have answered in any way. But it turned out that at the very edge of Hubble, we were able to find this primitive galaxy and could actually see it with the Spitzer Space Telescope – we could show that there was a blurry spot there. It remained a real conundrum for, like, seven years. We haven’t been able to learn much about it, but it did indicate a very interesting change in the way galaxies were accumulating in the beginning. So, when Webb went live, the big question was: is this item unique? Or are there many others like that?
Within four days of releasing the Webb data from early to mid-July, we had already sent a document to the prepress server. In fact, there were two groups doing it on the same day, saying we discovered a couple of other objects like that, and one of them was even further away. This was the kind of step we hoped Webb would take, that he would broaden our horizons in earlier times, and he did it incredibly quickly and very well.
I think this goes back to the point of working to get Hubble into space, but already thinking about the next thing. Now, it looks like the James Webb is happening very quickly, but that’s because there is already such a broad scientific basis.
Yes exactly. In the late 1990s, after the release of Hubble Deep Field, the goal of finding the first galaxies became Webb’s central goal. But it was around that time that we discovered the first exoplanets. Dark energy and dark matter were discussed. There were so many things Hubble was finding out about that we knew Webb was going to make a difference – in the end we had to wait 23 years.
In July, when the first images were released, we had an hour where we were all seeing them for the first time. I was sitting in the same space telescope auditorium where we first held the meeting 33 years ago. It was a little weird sitting there, looking around looking at God, this room looks more or less the same as it did when we first talked about Webb, and here we are now seeing the first images that arrive. And they are absolutely fantastic.
A particularly juicy aspect of the James Webb is that some new data appear to contradict previous findings. Can you tell us more about that early galaxy which was much more massive than expected?
Yes, of course. So this, which we have given the name GNZ11, is not a very fancy name, but astronomers are quite boring when it comes to naming objects. [laughs] – pointed to something unusual in these very early days.
So, in the first four days after the release of the Webb images, we wrote these articles and realized that GNZ11 was not unique: there were more of these very bright and very bright galaxies, which we interpreted as unusually massive. Then, within a few weeks, there was another one even further back in time, closer to the Big Bang, which was still very massive. It was really a surprise. We have to ask ourselves: is it really impressive? Or does it have really unusual stars that are very bright, but not so much mass? We don’t know at this point, but Webb can answer these questions.
What we need to do now is go in and look at those objects in more detail, see if we can learn more about what’s actually in that galaxy. How are the stars, if there are many smaller stars that contribute a lot of mass. Theorists are now asking themselves: How do you build a galaxy like this so quickly, and it also has a black hole that built up very quickly? Are we received? Galaxies can be quite complicated. The universe can play with you, even when you have Webb-quality data, but not enough.
What do you think a situation like this says about the scientific process itself?
This is interesting, because I would say that in the past there was a very slow process of doing things. The data didn’t come very fast. We spent a lot of time working on it, sometimes you had to go back and get more. Then, you know, the cards would come out and we’d be pretty final. The papers come out, everyone thinks “oh, this is great”. Then a year later, some new data comes in that says “well, that was wrong”. You have to recognize that you can be wrong at any time, but when you do wrong you learn new things.
I think I never felt particularly bad if people took care of doing the best they could at the time, and then come back and review things. Getting it wrong isn’t bad, it’s part of the process. And it is probably inevitable at this stage.
Webb has been busy. Is there a next goal on his list that you are particularly excited to see and learn more about?
Yes, the large image that was originally shown, of the galaxy cluster, indicated what I think will be extremely valuable in the future for learning more about galaxies. But I don’t just want to emphasize distant galaxies – exoplanets are going to be awesome and then, of course, those star-forming regions like Carina and the Tarantula Nebula. Those look great, but there’s also an incredible amount of science in those.
And I would just say, you know, when I was sitting there looking at the first pictures, I was blown away by their beauty and the character there, by the information. But one of the things I was thinking about next was: in that hour, I saw, like, six sets of data. I have to say that I am more data than I have ever seen from anything in any reasonable period of time in my entire life. Scientists will be working on those on their own for years, because there is so much information in those. And that was just an explorer – I mean, that was tens of hours of time, so we’re going to multiply that by 100, 1000 times a year.
One of the things I am often asked is: why is it important? That’s a lot of money. I have often thought about it and I think the human race has a deep interest in our origins. We are interested in how we were born, how life was born. And then you really go, well we’re sitting on this little planet, how are planets formed? You can take this question of origins, and that’s what astronomy is all about. Webb, Hubble, these things are just early machines. And what I really like about it, in so many ways, is that we live in a very divisive environment, and this interest crosses all these political and non-political areas wonderfully.
It’s one of those places where we still have common interests, which I hope we can expand in the future! At least Webb should contribute to this.
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