Katie Bouman is known for her work in compiling the first images of an event horizon—the “surface” of a black hole.
Credit: © Caltech

March is Women’s History Month, an annual observance of women’s achievements and contributions to society. This month, Behind the Headlines will feature woman pioneers in a variety of areas.

Women achieve great things around the world every day. However, not many women craft an algorithm to create the first-ever picture of a black hole. American computer scientist Katie Bouman worked on compiling the first images of an event horizon—the “surface” of a black hole. A black hole is a region of space whose gravitational force is so strong that nothing can escape from it. At the event horizon, the pull of gravity becomes so strong that nothing known can escape. Capturing the event horizon was considered an amazing feat of astronomical imaging. Bouman has helped us understand the universe’s greatest mystery.

Katherine Louise Bouman was born May 9, 1989, in West Lafayette, Indiana. While in high school, she volunteered at Purdue University, conducting imaging research. She attended the University of Michigan from 2007 to 2011, where she graduated summa cum laude (with highest distinction) with a bachelor’s degree in electrical engineering. She received her Ph.D. degree in electrical engineering and computer science from the Massachusetts Institute of Technology (MIT) in 2017.

Bouman joined the Event Horizon Telescope (EHT) project in 2013. The EHT is a global network of ground-based telescopes established to produce images of black hole event horizons. At MIT, she worked to develop the mathematical framework used to assemble images of black holes from radio telescope data. She led the development of the Continuous High-Resolution Image Reconstruction using Patch priors (CHIRP) algorithm. An algorithm is a step-by-step mathematical procedure, often carried out by a computer. The CHIRP algorithm takes images of one object from multiple sources and uses computer vision techniques to produce a single sharper image of the object. Computer vision is the use of computers to recognize patterns in images, a major topic in artificial intelligence.

In 2017, radio telescopes participating in the EHT project observed the M87 galaxy. The following year, Bouman headed one of the four EHT teams that used the data gathered to produce possible images of the supermassive black hole astronomers suspected to be at the center of M87, called M87*. Two teams, including Bouman’s, used algorithms similar to CHIRP. Two other teams used an algorithm traditionally used in radio astronomy. The teams then checked their images against one another.

In 2019, EHT released the combined image of M87*. At that time, two photographs of Bouman garnered significant media attention. The first showed her reaction as her team’s results were compiled for the first time. The second showed her posing with the hard drives of data used to compile the image of M87*. This photograph drew comparisons to a 1969 image of the American computer scientist Margaret Hamilton standing next to a stack of volumes containing the printed computer code for the Apollo lunar missions.

Nicole Aunapu Mann became the first Indigenous American woman in space in October 2022 aboard NASA’s SpaceX Crew-5 mission to the International Space Station.
Credit: NASA

Nicole Aunapu Mann is an American astronaut and Marine Corps test pilot. Today, October 5, 2022, Mann became the first Indigenous (native) American woman in space. Mann and three other astronauts launched on National Aeronautics and Space Administration’s (NASA) SpaceX Crew-5 mission to the International Space Station (ISS). While aboard the ISS, Mann will serve as a flight engineer. Mann is a member of the Wailacki people of the Round Valley Indian Tribes. The Round Valley Indian Tribes is a confederation of tribes designated to the Round Valley Indian Reservation in Mendocino County, California.

In 2013, the NASA chose Mann to be an astronaut. Mann completed astronaut training in July 2015. She led the development of the Exploration Ground Systems (EGS) launch facility, the Orion crewed spacecraft, and Space Launch System (SLS), built to carry the Orion craft into space. NASA selected Mann to serve as mission commander on NASA’s SpaceX Crew-5 mission on the Crew Dragon capsule en route to the International Space Station. SpaceX is a private company that owns and operates the rocket and spacecraft used in the mission. A Falcon 9 rocket was scheduled to launch the mission’s Crew Dragon capsule.

Mann joined the United States Marine Corps in 1999 as a second lieutenant. She reported to the Naval Air Station in Pensacola, Florida, for flight training in 2001. Mann became a Navy pilot in 2003 and began her operational flying career in 2004.  Mann deployed twice to Afghanistan and Iraq, completing 47 combat missions. After her deployments, she completed Navy Test Pilot School and served as a test pilot for many types of naval aircraft.

Nicole Victoria Aunapu was born in Petaluma, California, on June 27, 1977. She enrolled in the United States Naval Academy in Annapolis, Maryland, in 1995. Mann earned a bachelor’s degree in mechanical engineering in 1999. She completed a master’s degree in mechanical engineering from California’s Stanford University in 2001. In 2009, she married Navy pilot Travis Mann.

December 22, 2017

On Dec. 22, 1937, 80 years ago today, the center tube of the Lincoln Tunnel opened to motor traffic, connecting midtown New York City with Weehawken, New Jersey. Funded by the the Public Works Administration (PWA), the tunnel was built beneath the Hudson River by the Port Authority of New York and New Jersey, putting thousands of people to work during the Great Depression. A terrific engineering feat, the tunnel eased commutes in the burgeoning metropolis. Named after Abraham Lincoln, the tunnel followed the completion of the Holland Tunnel, also under the Hudson, in 1927.

Workers load rubble onto tram cars during the excavation of the Lincoln Tunnel in April 1935. Credit: The Port Authority of New York

Construction on the Lincoln Tunnel began in March 1934, and crews worked from both sides of the Hudson River. The work of the sandhogs—as workers who dig tunnels are sometimes known—was dangerous and claustrophobic. To reach the construction sites beneath the river, crews had to pass through air locks that eased them in and out of the high pressure areas. Dynamite exploded, giant drills roared, and tram cars rattled as workers braced the tunnel’s excavation with concrete and hundreds of giant iron rings. The New Jersey and New York workers met beneath the river for the first time in August 1935.

Temporary lighting illuminates the Lincoln Tunnel in October 1937, two months before it opened to motor traffic. Credit: The Port Authority of New York

Today, the Lincoln Tunnel has three tubes, each with two traffic lanes. The 8,216-foot (2,504-meter) center tube carries vehicles in either or both directions, depending on traffic needs. Westbound vehicles travel in the 7,482-foot (2,281-meter) north tube, opened in 1945. The 8,006-foot (2,440-meter) south tube is for eastbound traffic. The completion of the south tube of the Lincoln Tunnel in 1957 brought the total cost to about $190 million. More than 20 million vehicles use the tunnel every year. Today’s cash toll for using the bridge—$15 for cars—is slightly higher than the original fare of 50¢.

As late as 1900, Manhattan was not connected with New Jersey by either bridge or tunnel. A few bridges crossed the narrow Harlem River on the north, connecting Manhattan with the Bronx. Brooklyn Bridge, across the East River, connected the lower end of Manhattan with Long Island. But the thousands of New Jersey people who worked in Manhattan had to cross the Hudson River every day by ferryboat. This was the same method that the Dutch settlers had used nearly 300 years before. Today, seven tunnels under the Hudson River connect Manhattan with New Jersey. The tunnels are used for rail, automobile, truck, and bus traffic. Construction of other routes beneath the river is ongoing.