Astrophysicist Kim Arcand is Helping Everyone Experience the Universe
A supernova, by nature, isn’t something you can touch or feel—at least, not in any survivable way. And yet, there was Kim Arcand, standing on stage giving a TED X talk about her work with NASA’s Chandra X-ray Observatory, holding the remains of an exploded star.
In her 2016 talk, “How to Hold a Dead Star in Your Hand,” Arcand explained how she and her colleagues used NASA’s data to create a 3D model of the Cassiopeia A (Cas A) supernova remnant, a star 11,000 light years away, whose dying light reached Earth only 300 years ago. It was notable not only because the project combined data from different telescopes and observatories to create a 3D model of an exploded star but also because her team used that data to create a physical 3D-printed representation of that star.
It was the first time someone was able to “hold” a dead star, making a much-studied astronomical phenomenon into a tangible item. (Granted, that star model is scaled down. The actual size, Arcand said, is “400 million billion times the surface area of our sun and planets.”)
But the Cas A model is also significant because that sophisticated data was turned over to the public in a fully accessible way. Not only is the print available for download so that anyone with access to a 3D printer can create their own replica of a supernova remnant, but the accompanying virtual reality experience works with any smartphone and allows people to see inside the supernova in an immersive way using tools that most people already have in their pockets.
That level of accessibility to the cosmos is Arcand’s main goal. Arcand is the Visualization Scientist and Emerging Technology Lead at the Chandra X-ray Observatory, a NASA and Smithsonian Astrophysical Observatory project based at Harvard University, and part of her job is to take information about space and deliver it to as many people as possible, in as many ways as possible.
The most powerful X-ray telescope in the world, Chandra can perceive X-rays undetectable on Earth, and it delivers data about the universe that is, so far, unavailable any other way. It studies the high-energy universe, and is a sister telescope to the Hubble Space Telescope. Besides the remnants of that collapsed Cas A star, Chandra has shown us the supermassive black hole, Sagittarius A*, at the center of the Milky Way; an enormous galaxy, Perseus A, cannibalizing the smaller Perseus Cluster; the most fully-realized images we’ve ever seen of the Crab Nebula and the Andromeda Galaxy; and compelling evidence that dark matter, which cosmologists think makes up the bulk of the universe, actually exists.
All of that sounds impressive—but unless you’re an astrophysicist who can actually interpret the 50 Blu-ray discs worth of data that Chandra collects every day, you’re probably not going to be able to make much sense out of what those discoveries are, or why they’re significant.
“We care about things like exploded stars because the seeds for life, the elements that we need, are created in their furnaces…”
That’s where Arcand comes in. Her work is to take the data the observatory gathers and turn it into images and experiences that are meaningful to the public. The data comes in as binary code and becomes vivid images that use color to illuminate topography, or to illustrate chemical composition or temperature levels. “It adds to the information quotient of the image,” Arcand said in her Ted talk. Those images then become other experiences, such as virtual or augmented reality immersions or specs for 3D printed objects.
Lately, finding ways for people with visual impairments to experience the cosmos is at the forefront of Arcand’s work. “Having this collection of astronomical objects that you can very easily put into some other 3D production pipeline,” using emerging technologies like holograms and data sonification, she says, “just means that when it comes to designing an output for the user, you can be highly specific. You can really take that visualization and mold it to the audience that you best want to communicate with.”
For the visually impaired, tactile models offer an immersive experience of astronomical phenomena that, until recently, have not been fully accessible to them. Being told what an exploded star looks like is a very different experience than touching one, especially if you’ve never seen a star to begin with.
“We now have about nine models of various objects we have 3D printed that we have either tested with people who are blind or visually impaired, or we are in the process of testing now,” she said. Most of them are exploded stars, pulsars or mature stars, mostly nearby (in cosmological terms) our own Milky Way galaxy.
Testing the models with people with sight impairments, Arcand said, has improved their model-making for everyone, through suggestions like segmenting 3D models so that people can see and feel what the inside of a supernova remnant is like. “They're sort of spherical shells of high energy material that expand radially outwards,” she explained. “If you 3D printed in a hard plastic, it seems like it's a solid ball, right? But it's not, it's a shell. Inside has just as much texture as the outside of this 3D print. If you can't see the model, however, it's not going to be as apparent because you can't see through some of the holes and gaps that someone who is sighted can see. So we cut the model in half for people to be able to open.”
“That sort of experiential aspect, the ability to manipulate and take apart a model, adds something for people who are sighted, too,” she explained. “It’s that universal design mentality that we’ve been trying both to learn about and implement.”
One of the biggest challenges, which also has also reaped the biggest reward, is translating virtual reality experiences into meaningful interactions for people who are visually impaired. “A virtual reality application is typically pretty heavily weighted towards someone who is sighted,” Arcand said. “We try to make them so that if you’re vision impaired, they’re still very friendly. My goal was to take data in that geospatial bubble and attach sound to it that was also spatially aware.”
The result of that work is data sonification—the process of turning information into sound—that allows the user to hear outer space. The tones change as you move through the model, either looking at it or just listening to it. “You’re moving through this object, and whether you’re sighted or not, you’re still experiencing the information in different, multimodal ways,” Arcand explained. “You can hear the pitch and the sound type changes of the supernova material. You can hear the calcium versus the silicon versus the iron — and as you’re moving through that space, the density of information changes respectively.”
The data sonification work was happening with Arcand and her research group of students and faculty at Brown University in Providence, Rhode Island, so the pandemic paused their progress —but that, she said, was actually a good thing. While the school is closed, she’s been able to rethink the process, and is collaborating with sound experts while Brown is closed. “We were able to think of other projects we could do with data sonification and a simpler, two-dimensional format,” Arcand explained. They’re now developing sonifications that can be experienced through web browsers, and a phone application, using haptic technology to help you feel vibrations through the phone to indicate changes in space. “It’s something useful not just for people who are blind or visually impaired, but others as well. I think a lot of learners can do well with that sort of multi-access point.” Some such sonifications can be heard online now.
One of the things Arcand often says in her talks is that learning about the cosmos is important not just for the knowledge of space itself, but because knowing more about the universe helps us understand ourselves as well.
“We care about things like exploded stars because the seeds for life, the elements that we need, are created in their furnaces. And when they explode and spew their guts out into the universe, they are eventually swept up and create the new generations of stars and planets,” she said in her TED talk. “The iron in our blood, the calcium in our bones, the gold in our jewelry ... they come from those previous generations of stars.”
Image Credit: X-ray: NASA/CXC/INAF/R. Gilli et al.; Radio NRAO/VLA; Optical: NASA/STScI
