UC Santa Cruz astronomer Garth Illingworth, former deputy director of the Space Telescope Science Institute, has had quite the career.
He spent decades researching and understanding the most distant galaxies and was one of the leaders of the team that built the Hubble Space Telescope. And even before Hubble was in the sky, it had already started developing the James Webb Space Telescope (JWST) – yes, this The James Webb Space Telescope, the one currently wowing the minds of Earthlings on a daily basis with insanely beautiful images of our universe.
While most of us look at these JWST images and only see images, Illingworth and his peers see all of this and more: data. In its few months of operation, Webb has already offered an illuminating breadth of information – discoveries that have confirmed, confounded and even contradicted existing theories about the cosmos. Curious to know what this data means for 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 considerable. Can you tell us a bit about your research and where it led you?
Garth Illingworth: Of course, I will give you the scientific framework. I am an astronomer and my main interests are the first galaxies in the universe. Basically, we live 13.8 billion years after the Big Bang in a large, wondrous spiral galaxy, the Milky Way. But it had to come to this.
The very beginnings have intrigued me for a long time, ever since I saw the Hubble Deep Field in 1995 – Hubble’s first deep image of a pristine part of the sky, which turned out not to be empty, but just absolutely filled of galaxies. It’s what I’ve been working on for about 25 years. In fact, back in the 80s when I first started thinking about Webb, we hadn’t even launched Hubble. Riccardo Giacconi, the director of the Space Telescope Science Institute at the time, told me, “You really need to work on the next big telescope. Believe me, it’s going to take a long time.”
We had to do something quite interesting at that time. We had to look ahead, even when we didn’t know what Hubble was going to find. We realized we should go to longer wavelengths, we really should go into the infrared – we felt there were so many ways this could reveal aspects of the universe that Hubble wouldn’t. never. You needed a big telescope to work in the infrared. It must have been really cold, which meant it had to be far from here. When you look at the designs now, these very simple-minded designs, it’s completely different from Webb, but actually Webb works and has the features that were thought of then. It’s a big telescope, it’s infrared, it’s very cold, it’s damn 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 oldest galaxy humans have ever seen, dating back around 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 have done this, I would have said no. But it turned out that just at the edge of Hubble, we were able to find this early galaxy, and we were able to see it with the Spitzer Space Telescope – we were able to show that there was a fuzzy blob there. It remained as a real enigma for, like, seven years. We couldn’t learn much about it, but it indicated a very interesting change in the way galaxies were building in early times. So, by the time Webb became operational, the big question was: is this object unique? Or are there many others like it?
Within four days of the release of the Webb data in early to mid-July, we had already submitted an article to the preprint server. In fact, there were two groups to do it on the same day, saying we had discovered a few other objects like this, and one of them was even further away. It was the kind of step we hoped Webb would make – that he would expand our horizons to earlier eras, and he did it incredibly quickly and very well.
I think it boils down to 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’s such a strong scientific basis already.
Yes exactly. In the late 1990s, after the release of Hubble Deep Field, the goal of finding the first galaxies became Webb’s central focus. But around this time, we discovered the first exoplanets. We were discussing dark energy and dark matter. There was so much Hubble was finding out about that we knew Webb would make a difference – we ended up having to wait 23 years.
In July, when the first images came out, we had an hour where we saw them all for the first time. I was sitting in the same Space Telescope auditorium where we had the first meeting 33 years ago. It was kind of weird sitting there looking around God, this room looks pretty much the same as when we first talked about Webb, and here we are now seeing the first footage coming in. And they are absolutely amazing.
A particularly juicy conclusion from James Webb is that some new data seems to contradict previous findings. Can you tell us more about this early galaxy which was much more massive than expected?
Yes of course. So this one, which we named GNZ11 – not a very imaginative name, but astronomers are pretty boring when it comes to naming objects [laughs] – pointed out something unusual in those very early days.
So in the first four days after the Webb images were published, we wrote these articles and realized that GNZ11 was not unique – there were other of these very bright, very bright galaxies, which we have interpreted as being exceptionally massive. Then, within a few weeks, there was another 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 huge? Or are there really unusual stars that are very bright, but not so massive? We just don’t know at this point, but Webb can answer those questions.
What we need to do now is go in and look at these objects in more detail, see if we can find out more about what is really in this galaxy. What stars look like, if there are lots of smaller stars that contribute a lot of mass. Theorists are now wondering: how does a galaxy like this build so quickly, and is there also a black hole building there extremely quickly? Are we deceived? Galaxies can be quite tricky. The universe can play games with you even when you have Webb-quality data, but not enough.
What do you think a situation like this reveals about the scientific process itself?
It’s interesting, because I would say that in the past there was a very slow process of doing things. The data was not coming in very quickly. We spent a lot of time working on it, sometimes we had to go back and get some more. Then, you know, the papers would come out, and we’d be pretty definitive. The papers come out, everyone thinks “oh, that’s great”. Then a year later new data comes in that says “well, that was wrong”. You must recognize that you can be wrong at any time, but when you are wrong, you learn new things.
I think I never felt particularly bad if people were careful to do the best they could at the time, then go back and revise things. Getting it wrong isn’t bad, it’s part of the process. And it’s probably unavoidable at this point.
Webb has been busy. Is there an upcoming target on his roster that you’re particularly eager to see and learn more about?
Yes, the large image that was originally shown, of the galaxy cluster, which was pointed at what I think will be extremely useful in the future for learning more about galaxies. But I don’t just want to focus on distant galaxies – exoplanets are going to be amazing, and of course those star forming regions like Carina and the Tarantula Nebula. These look gorgeous, but there’s an incredible amount of science in these too.
And I would just say, you know, when I was sitting there looking at the first images, I was blown away by how beautiful they were and the character there, the information. But one of the things I thought about afterwards was: in that hour, I saw, like, six sets of data. I have to say, that’s more data than I’ve ever seen on anything in a reasonable amount of time in my entire life. Scientists will be working on these for ages on their own, because they contain so much information. And that was just a scout — I mean, it was tens of hours of time, so we’re going to multiply that 100, 1000 times every year.
One of the things I often get asked is: why is this important? It’s a lot of
It’s one of those places where we still have common interests — which I hope we can expand on in the future! Webb should at least contribute to it.
Learn more about the James Webb Space Telescope: Scientists puzzled because James Webb sees things that shouldn’t be there
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