To Make the Invisible Visible

This Wednesday Dr. Katie Bouman and an international team of scientists and astronomers revealed to the world the first ever picture of a black hole at the center of the Messier 87 (M87) galaxy, a supergiant elliptical galaxy in the constellation Virgo 55 million light years away from Earth.

Between 1907 and 1915, Albert Einstein first articulated his general theory of relativity, which predicted that sufficiently compact mass can bend spacetime to form a black hole. While many of Einstein’s theories have been backed up with evidence collected in the past century, until this week humanity had never actually seen a black hole. ScienceNews exclaimed the significance of this discovery in their headline, “The first picture of a black hole opens a new era of astrophysics.”

For anyone who has seen the photo that went viral on Twitter of Dr. Bouman placing her hands in front of her mouth in sheer joy and amazement as her algorithm assembled thousands of terabytes of data collected by a network of global telescopes known as the Event Horizon Telescope, there is a hushed feeling of wonder and awe at seeing the first observable rendering of a black hole.

And while Bouman is the first to acknowledge that this discovery took a village of astronomers and scientists to collect the data and collaborate on this international project, it is her algorithm that allowed the rest of the world to see what once was invisible and unknown. Making a black hole visible is no easy feat considering that a black hole’s gravity is so massive that nothing, not even light, can escape across the event horizon, or the black hole’s edge.

As Bouman put it in her TEDx talk to an audience in Brookline, Massachusetts in November 2016: “Just as a forensic sketch artist uses limited descriptions to piece together a picture using their knowledge of face structure, the imaging algorithms I develop use our limited telescope data to guide us to a picture that also looks like stuff in our universe.”

Bouman’s delightful talk helps even non-scientists understand how the Event Horizon Telescope (EHT) team coordinated their efforts by comparing earth to a giant disco ball, whereby each individual mirror would collect the light of a black hole we could then make a complete picture of whatever we observed in space. The fact that we cannot create an Earth-sized telescope to capture black holes did not faze the EHT team. They instead used an array of observatories around the world coupled with Bouman’s algorithm to provide enough data to lead to the rendering released to the public on April 10.

The future discoveries we will be able to make because of the EHT team’s hard work are extraordinary to think about. Harvard University astrophysicist Avi Loeb, who is not on the EHT team, likens the black-hole visibility to the “shot heard round the world.” This time, instead of heralding the start of the American Revolutionary War in 1775 and the assassination of Archduke Franz Ferdinand in 1914, 2019 will be the year where we will begin to make greater strides in understanding how black holes behave.

And while Bouman is not an island in this important discovery, the fact that the 29 year old’s algorithm made this black hole visible, places her in the great and selective company of scientists such as NASA’s “human computer” Katherine Johnson, who calculated trajectory analysis to ensure safe space missions for Alan Shepard (1961) and John Glenn (1962); Lene Vestergaard Hau, who was the first scientist to stop light; and Vera Rubin, whose pioneering research on dark matter indicated that over 90 percent of the universe’s mass has never been seen.

Bouman’s contributions to science will not only be made visible, but her work will also help us better understand what, for so long, we could not see or think to capture until now.