In a worldwide effort, we now have our first picture of a black hole. “You’re basically looking at a supermassive black hole that’s almost the size of our solar system,” or 38 billion kilometers in diameter, said Sera Markoff, an astrophysicist at the University of Amsterdam.
Capturing and generating this picture required collaboration from scientists around the world. Jason Snell explains
To capture this image, the EHT used seven different radio telescopes all around the world in order to use something called interferometry, which combines data from telescopes spread out over a wide distance to essentially create a virtual telescope the size of the distance between the telescopes. The result is a telescope that’s basically the size of Earth. (Among the telescopes used is one at the South Pole, which needed to be retrofitted to make these measurements.)
Then the telescopes have to capture data simultaneously, which means the weather needs to be good in Hawaii and Spain and Chile and the South Pole and other places simultaneously. And when that data is captured, it needs to be brought back to a correlation facility to process it and generate a single data set.
The telescopes captured 5 petabytes of data: when stored on high capacity hard drives, it would fill up the back of a pickup truck. Andy Tanenbaum's quote from 1985 is as true today as it was 30 years ago: "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway." When you have petabytes of data to move from place to place, even fast internet connections aren't fast enough. To beat an airplane carrying several dozen hard drives to the MIT Haystack processing facility near Boston, the data captured at the Kitt Peak telescope in Arizona would have to be transmitted at a rate of approximately 14 gigabytes per second. That's like downloading 3-4 high definition movies per second.
I love the space and computer parts of this amazing project. But my favorite part is Katie Bauman's response. She got a lot of attention yesterday because she is female and she was a major contributor to the algorithmic processing required to generate the image that we have all been looking at the last couple of days. It's great to have another role model of a woman in STEM. But it's even better to see (no link because I hate Facebook) how she gracefully reminded us that it was a large team with many contributors.
All the parts of this story make me feel good inside.