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--:-- Sean Rameswaram: Welcome back to Today Explained. I'm Sean Rameswaram. Today, we're talking about the James Webb Space Telescope and its mind-blowing images of the universe.
--:-- Amber Straughn: Hi, I'm Amber Straughn, an astrophysicist at NASA's Goddard Space Flight Center.
--:-- Sean Rameswaram: Dr. Straughn, you're on a first-name basis with the James Webb Space Telescope. You're a scientist on the team at NASA for JWST.
--:-- Amber Straughn: That's right. I've been working on it for 11, 12 years now, officially. And I've been working on it even before then as a postdoc and grad student.
--:-- Sean Rameswaram: Which means you saw these mind-expanding images before they were cool. I mean, I don't think you have to be an astronomer to appreciate the beauty of these images.
--:-- Amber Straughn: And I think the past 30 years of Hubble has demonstrated that. The public loves Hubble because of these beautiful images.
--:-- Sean Rameswaram: And I think that was the exact reaction, although I don't think people actually know in most cases exactly what they're looking at.
--:-- Amber Straughn: So we were wondering if you could help us with that part of it. So broadly speaking, these first five images that were released sort of span a breadth of different science topics, ranging from exoplanets.
--:-- Sean Rameswaram: To looking at regions of star birth and star death. There are galaxies here in which you're seeing individual clusters of stars forming, popping up just like popcorn.
--:-- Amber Straughn: To other galaxies. Light from some of the most distant galaxies in that image has been traveling over 13 billion years.
--:-- Sean Rameswaram: So we are literally seeing galaxies as they were in the distant past, which is exactly what this telescope was designed to discover.
--:-- Amber Straughn: So the James Webb Telescope is essentially a time machine. That is literally true.
--:-- Sean Rameswaram: And it sounds sort of, you know, sci-fi. But it's actually due to a very sort of basic principle of physics, and that is the fact that light takes time to travel.
--:-- Amber Straughn: You're seeing a lamppost across the street. Light from that takes a tiny fraction of a second to reach your eye.
--:-- Sean Rameswaram: The light from the sun takes about eight minutes to get to the Earth.
--:-- Amber Straughn: So in essence, you're seeing the sun as it was eight minutes ago. Putting these powerful telescopes in space allows us to see things as they were literally back in time.
--:-- Sean Rameswaram: It's amazing. It's actually, it's the true definition of the word amazing.
--:-- Amber Straughn: Which of the images have been the widest circulated? Do you know?
--:-- Sean Rameswaram: My sense is, just from like looking at all the media reports and stuff, that people have fallen in love with the deep-filled image and also the Carina Nebula.
--:-- Amber Straughn: Those two seem to be the ones that I've seen popping up, but all of them are spectacular for their own reasons.
--:-- Sean Rameswaram: Let me pull up the deep field image first. There's a lot going on in this image. Where do you even begin to start talking about it?
--:-- Amber Straughn: I guess, what are we seeing broadly? Where are we? It's so much to take in, but I guess the first sort of thing to know about this image is it's a teeny, tiny piece of sky.
--:-- Sean Rameswaram: If you held a grain of sand out at arm's length. That's the amount of sky we're seeing here, which is incredible, right?
--:-- Amber Straughn: And in this grain of sand, we're seeing thousands of galaxies. I mean, it's absolutely incredible.
--:-- Sean Rameswaram: And to go a little bit more in detail, the sort of fuzzy white galaxies we see near the center of the image, those are making up a galaxy cluster.
--:-- Amber Straughn: Those are further away. They're sort of in the background. And essentially what's happening in this image and the reason you get those little arcs is that the combined mass of the fuzzy white galaxies and also crucially their dark matter is serving as this giant cosmic lens.
--:-- Sean Rameswaram: And so when light travels sort of through the universe from these distant galaxies and hits the mass of this galaxy cluster it gets bent and stretched out.
--:-- Amber Straughn: So that what all these little arcs that you seeing are sort of like you know looking through the bottom of like a glass and you see how light gets weird and distorted.
--:-- Sean Rameswaram: Proving once again that Einstein was right. Right about what?
--:-- Amber Straughn: The way the universe works and the way that mass can actually bend light.
--:-- Sean Rameswaram: The equation E is equal mc squared in which energy is equal to mass multiplied with the square of the velocity of light showed that a very small amount of mass may be converted into a very large amount of energy.
--:-- Amber Straughn: Is like anything we're seeing a star? Yes. The bright points of light that have spikes around them, so you can see several of those, those are actually stars within our own Milky Way galaxy, so relatively nearby.
--:-- Sean Rameswaram: Okay. So anything with a spike is a star. Everything else, every other point of light is a galaxy.
--:-- Amber Straughn: And of course, again, just to sort of go back to high school astronomy class, a galaxy is a grouping of stars. Our own Milky Way galaxy has a couple hundred billion stars.
--:-- Sean Rameswaram: And so each point of light you see in this image, aside from the individual stars with spikes, Every other point of light is an individual galaxy itself, probably with hundreds of billions of stars.
--:-- Amber Straughn: Okay, so that's like, that is actually mind-blowing. Because what you're saying is that the galaxies greatly, greatly outnumber the few spiky stars we're seeing in this photo, right?
--:-- Sean Rameswaram: Absolutely. The data's brand new, so we haven't done an actual count yet. But just by looking at this, I mean, there are thousands, right? There are thousands of galaxies here and just a few stars within the sort of foreground of the Milky Way.
--:-- Amber Straughn: So there's thousands of galaxies here which contain billions of stars. This photo is representative of holding a grain of sand up to the sky at arm's length.
--:-- Sean Rameswaram: Yeah. Right? Right, right.
--:-- Amber Straughn: It starts to give you a little tiny bit of a sense of just how big the universe is.
--:-- Sean Rameswaram: And is the James Webb telescope going to sort of pivot on an axis and give us all the other grains of sand?
--:-- Amber Straughn: What happens after this? Well, that would, of course, take a very long time.
--:-- Sean Rameswaram: But the good news is that taking these little teeny tiny snapshots of the universe helps to give us a sense of what the rest of the universe is like.
--:-- Amber Straughn: It's sort of just statistics because one of the fundamental assumptions in astrophysics is that the universe is sort of the same in all directions, roughly speaking.
--:-- Sean Rameswaram: So you can imagine that point anywhere in the sky and you would see roughly this many galaxies.
--:-- Amber Straughn: Now, that's a little bit maybe not quite true because this is a galaxy cluster in the foreground.
--:-- Sean Rameswaram: But of course, we have examples from Hubble, and we will soon have examples from JWST of just sort of clear deep fields, like deep fields of galaxies without the intervening galaxy cluster here.
--:-- Amber Straughn: Incredible as that is, let's pivot to another photo here, one that Marina Korin at the Atlantic called the coolest space picture I've ever seen.
--:-- Sean Rameswaram: And this is, of course, the aforementioned nebula, Karina Nebula, is that right?
--:-- Amber Straughn: This was the image that made me cry when I first saw it. You know, it's just so stunningly beautiful.
--:-- Sean Rameswaram: And I love how it, I mean, it sort of brings the universe to life, right? You can see texture and structure and depth.
--:-- Amber Straughn: It's gorgeous. And what exactly is it? It looks like some sort of like cotton candy cloud up in deep space.
--:-- Sean Rameswaram: Yeah, well, maybe not cotton candy, but it is sort of a cloud.
--:-- Amber Straughn: So the Carina Nebula, which the team sort of nicknamed Cosmic Cliffs, which I think is great.
--:-- Sean Rameswaram: But the Carina Nebula is a relatively nearby star forming region within our Milky Way galaxy.
--:-- Amber Straughn: It's about 7,600 light years away. So, you know, relatively nearby.
--:-- Sean Rameswaram: But it's basically a stellar nursery. So the orange stuff you see in this image is basically gas and dust.
--:-- Amber Straughn: And then above the sort of ridge of the nebula here, up above sort of out of the frame of view, are some really hot, young, gigantic stars.
--:-- Sean Rameswaram: And these stars have immense amounts of radiation and stellar winds and so you can imagine that radiation and wind is sort of pushing down on this region of gas and dust.
--:-- Amber Straughn: And these processes are some of what help newborn stars to form so it really is you know a stellar nursery.
--:-- Sean Rameswaram: What is the information collected thus far by the telescope reveal about the universe that we didn't already know?
--:-- Amber Straughn: The type of light this telescope sees, this is infrared light, which is light that's a little bit more red than what your eyes can see.
--:-- Sean Rameswaram: And this is the first time we've ever gotten a spectrum of an exoplanet in these certain longer wavelengths of light, which is super exciting.
--:-- Amber Straughn: But in terms of what we've learned, this is just a first look. And so scientists are already busy sort of digging into the data.
--:-- Sean Rameswaram: But the most impressive thing to me was this chemical, you know, fingerprint of this extremely distant galaxy.
--:-- Amber Straughn: We're starting to get a hint to learn what these distant galaxies are made of, because we've never been able to see that before.
--:-- Sean Rameswaram: And this was one of the main drivers for building this telescope the way that we did.
--:-- Amber Straughn: So, you know, over the course of the last 30 years with Hubble, we've been able to learn incredible things about galaxies, about how the universe works in the sense of how galaxies change over time.
--:-- Sean Rameswaram: And with Hubble, we've been able to look back pretty far into the distant past. But Hubble was not able to see the very first epic of galaxies that were born after the Big Bang.
--:-- Amber Straughn: So we're talking about looking back in time about 13 and a half billion years into the past. That's a part of space we have never seen before.
--:-- Sean Rameswaram: And this telescope was designed to find those first galaxies.
--:-- Amber Straughn: And this very first deep image was a relatively short image it just like a snapshot.
--:-- Sean Rameswaram: And what we see what this image shows us is that we will be able to do that.
--:-- Amber Straughn: We think we will be able to learn what that first epic of galaxies was like, that set off the whole evolution of the universe.
--:-- Sean Rameswaram: That thing Dr. Amber Straughn from NASA said about this telescope seeing infrared light? That's the reason all of these images have been painstakingly doctored.
--:-- Joshua Sokol: Yeah, it is true. They're all mediated. Mediated?
--:-- Sean Rameswaram: Is that a euphemism?
--:-- Joshua Sokol: Well, there's technology interfering between what's out there in the universe and what you're seeing.
--:-- Sean Rameswaram: And this is kind of something that we accept in other situations. You know, our phone cameras and our cameras in general, digital cameras, all kind of are creating a vision of reality.
--:-- Joshua Sokol: They're trying to create something that mimics what our eyes do, but it's not exactly real, I guess.
--:-- Sean Rameswaram: I see what you're saying there because I've noticed I recently went from an iPhone 5 to an iPhone 13.
--:-- Joshua Sokol: And what I'm noticing now, especially when I take photos at night, is that my iPhone's rendering of events, this iPhone 13, is actually much better lit than what I actually see with my human eye.
--:-- Sean Rameswaram: Which is the more accurate reality? Is that like an existential question?
--:-- Joshua Sokol: Yeah, it gets philosophical really quick. I mean, if you think about the romantic notion of an astronomer as somebody who puts their eye up to the lens of a telescope and looks at the universe and they perceive it all through their eyeball, the reality hasn't been like that for a while.
--:-- Sean Rameswaram: And also that's not the way our photography works. We're creating almost like a data visualization of your iPhone or the telescope.
--:-- Joshua Sokol: It creates an array of numbers. It takes in some data from the universe. And then there's this added step of like, how do we want to visualize that? Do we want to make it look exactly mimicking how your eye might see it?
--:-- Sean Rameswaram: Granted that people's eyes are different and lighting conditions are different, you know?
--:-- Joshua Sokol: Or are you trying to show other things? So what you're saying is the telescope's up there capturing ones and zeros.
--:-- Sean Rameswaram: And the question is, how do we want to represent those ones and zeros?
--:-- Joshua Sokol: The telescope is not up there to make really, really cool pictures. It's up there to take data about what's in the universe.
--:-- Sean Rameswaram: And what this kind of breaks down to is like, in every pixel of this image, how much light do we see from the universe?
--:-- Joshua Sokol: And that's all that the telescope wants to do. Everything past that point of how would it look to us and how can we visually communicate what it's seeing and what it's doing, that's all a little bit subjective, a little bit of interpretation.
--:-- Sean Rameswaram: It is a data visualization.
--:-- Joshua Sokol: What's coming across their desks in its raw form? Is it black and white?
--:-- Sean Rameswaram: Yeah. Well, the raw data is black and white.
--:-- Joshua Sokol: Or I challenge you to imagine something even more abstract.
--:-- Sean Rameswaram: Huh. What it really is, is an array of numbers.
--:-- Joshua Sokol: And the array of numbers is just like, how bright was the universe in each pixel? Like, this pixel saw 100 photons from this crazy galaxy, and this one saw a little bit less.
--:-- Sean Rameswaram: And it's just an array of numbers.
--:-- Joshua Sokol: What astronomers do on their computers is like, immediately translate that into a black and white, like a grayscale image.
--:-- Sean Rameswaram: Of let's see it. That will help me understand it because I don't want to look at just a matrix code. You know, I want to see an image.
--:-- Joshua Sokol: So the really raw is the array of numbers The kind of the way that then that visualized is like let translate this into an image a digital image black and white image for sure
--:-- Sean Rameswaram: Does that feel sort of distinct from the way say our smartphones, our Google Pixels, and our iPhone 13s are interpreting a landscape photo shot at night?
--:-- Joshua Sokol: Because here you're talking about actual black and white, ones and zeros, numbers of photons, And then what you end up with is this sort of stunning image of the Carina Nebula, which people actually look at and can't believe what they're seeing.
--:-- Sean Rameswaram: And it sort of turns out, well, that isn't exactly what anyone saw.
--:-- Joshua Sokol: I think there's an analogy that holds up pretty well between the phone and the telescope. And then it breaks down towards the end.
--:-- Sean Rameswaram: The way that our cameras, our regular cameras work is they're also really creating arrays of numbers, black and white images.
--:-- Joshua Sokol: And then they're combining them and they're assigning colors to them, digitally combining them.
--:-- Sean Rameswaram: They're showing us something that makes visual sense. A lot of times their goal is to recreate kind of how our eyes work and do something that looks like the kinds of things we see, but they might punch it up in certain ways because they're also trying to create something that's pleasing to us and contains the information about the scene that we want to see.
--:-- Joshua Sokol: The thing is, when your phone does this, you're not involved in the process at all. It's all like underneath the hood in a black box.
--:-- Sean Rameswaram: And what's happened with these telescope images is there were people involved at every step, decisions made at every step.
--:-- Joshua Sokol: And it's just much more intentional about what is being communicated in the images.
--:-- Sean Rameswaram: If I was actually shooting by the Carina Nebula in a spaceship, would it actually look like that? No, it would not actually look like this.
--:-- Joshua Sokol: I have to confess it would not. Whoa. It would still look really cool.
--:-- Sean Rameswaram: Bummer. What would it look like? I mean, it would look cloudy, and you would see a lot of these structures, and you would definitely see less color with your eyes.
--:-- Joshua Sokol: And you cheated a little bit in your example because you said you're there in a spaceship, like at warp speed.
--:-- Sean Rameswaram: So you're still implying there's this technological mediation going on to get you close to this thing that, like, I promise you no human being in the next thousand years will ever be close to.
--:-- Joshua Sokol: Corina Nebula, visually, your eyes could see a lot of cloudiness, a lot of structure, a lot of color.
--:-- Sean Rameswaram: It would not be this vivid. It's fake in the sense that all images are sort of fake.
--:-- Joshua Sokol: But it's hyper real. It's super humanly real. It's beyond what you could do.
--:-- Sean Rameswaram: And that's what's cool about it, too.
--:-- Joshua Sokol: It seems like such an enormous responsibility because these images are essentially now the historical record.
--:-- Sean Rameswaram: I mean, they have entered the public consciousness and that's how people will think about James Webb.
--:-- Joshua Sokol: How does NASA walk the line between getting the public excited about what this telescope is doing and representing fairly what it's actually seeing?
--:-- Sean Rameswaram: These images are a conscious act of visual communication.
--:-- Joshua Sokol: Part of that is almost brand management. It's like communicating, hey, here's this thing that we do that's very legible to the average person, this amazing image that you can appreciate and see.
--:-- Sean Rameswaram: So it'll make the argument that the telescope that costs all this taxpayer money is worthwhile, that it's functioning well, that it's capable of doing amazing things.
--:-- Joshua Sokol: That's kind of a cynical thing almost. We want to inform public perception of what this large public project is doing.
--:-- Sean Rameswaram: The other part is that NASA is required with its spending to explain itself to do science communication.
--:-- Joshua Sokol: So you could also imagine the telescope is just taking all this really technical data, but it's not showing anything. Nobody benefits from the knowledge generated.
--:-- Sean Rameswaram: So there is this very genuine, earnest desire in the people that work on this to show, like, this is how we see the universe, this is what we can learn about it, this is what you paid for, let me explain how it works.
--:-- Joshua Sokol: The colors are not fake to convince people to fund NASA more. The colors are punched up and combined and made aesthetically pleasing to communicate real information about just how precisely the telescope can see the universe.
--:-- Sean Rameswaram: That it can really see this thing that looks red in the image, that's this stuff out in space.
--:-- Joshua Sokol: And this blue in the image is a totally different physical process. and, hey, look, isn't it amazing that we built this thing that can tell that difference?
--:-- Sean Rameswaram: I mean, it's better than what our eyes can see. It's more informative, and that's why they're doing it.
--:-- Joshua Sokol: And if they released it in black and white, no one would care. If they released it in black and white, they'd be showing off less of what the thing's true capabilities are, and they would be less impactful on an audience.
--:-- Sean Rameswaram: They would be boring.
--:-- Joshua Sokol: Joshua Sokol is a freelance science writer.
--:-- Sean Rameswaram: Earlier in the show, you heard from Dr. Amber Straughn. She's with NASA.
--:-- Victoria Chamberlain: Our program today was produced by Victoria Chamberlain.
--:-- Sean Rameswaram: Matthew Collette edited.
--:-- Victoria Chamberlain: Laura Bullard fact-checked.
--:-- Sean Rameswaram: Paul Mounsey engineered.
--:-- Victoria Chamberlain: We had help from our friends at Unexplainable, especially Dr. Brian Resnick.
--:-- Sean Rameswaram: They just re-released their two-episode series on the James Webb Space Telescope.
--:-- Victoria Chamberlain: If you want to hear more about what exactly this telescope is looking for in outer space, look for Unexplainable wherever you listen.
--:-- Sean Rameswaram: This is Today Explained. Thank you.
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