The development of the algorithm that made it possible to create the first image ever of a black hole was led by computer scientist Katie Bouman while she was still a graduate student at MIT. Bouman shared a photo on Facebook of herself reacting as the historical picture was processing.
The algorithm, which Bouman named CHIRP (Continuous High-resolution Image Reconstruction using Patch priors) was needed to combine data from the eight radio telescopes around the world working under Event Horizon Telescope, the international collaboration that captured the black hole image, and turn it into a cohesive image.
Bouman is currently a postdoctoral fellow with Event Horizon Telescope and will start as an assistant professor in Caltech’s computing and mathematical sciences department, according to her website.
The development of CHIRP was announced in 2016 by MIT and involved a team of researchers from three places: MIT’s Computer Science and Artificial Intelligence Laboratory, the Harvard-Smithsonian Center for Astrophysics and the MIT Haystack Observatory. As MIT described it three years ago, the project sought “to turn the entire planet into a large radio telescope dish.”
Since astronomical signals reach the radio telescopes at slightly different rates, the researchers had to figure out how to account for that so calculations would be accurate and visual information could be extracted.
As MIT explained:
Bouman adopted a clever algebraic solution to this problem: If the measurements from three telescopes are multiplied, the extra delays caused by atmospheric noise cancel each other out. This does mean that each new measurement requires data from three telescopes, not just two, but the increase in precision makes up for the loss of information.
The algorithm then reconstructed and refined the original images to prepare the final historical image of the black hole. CHIRP can also be used for any imaging system that uses radio interferometry.
So much data was collected by Event Horizon Telescope that it had to be shipped to the MIT Haystack Observatory on half a ton of hard drives.
Left: MIT computer scientist Katie Bouman w/stacks of hard drives of black hole image data.
Right: MIT computer scientist Margaret Hamilton w/the code she wrote that helped put a man on the moon.
— MIT CSAIL (@MIT_CSAIL) April 10, 2019
To learn more about how the algorithm was developed, check out Bouman’s 2016 TED talk: