Imagine a black hole like listening to a broken piano, says a scientist

The American computer scientist Katie Bouman, who caused a stir in her role in creating the first image of a black hole in the world, described the tedious process as listening to a piano at the keys broken.

During his testimony before Congress Thursday, the Harvard Smithsonian Astrophysics Center postdoctoral fellow also suggested that the technology developed by the project could have practical applications in the fields of medical imaging, forecasting seismic and autonomous cars.

A photo released last month on the star-devouring monster at the heart of the Messier 87 galaxy (M87) revealed a dark nucleus surrounded by a pale orange halo of white and hot plasma.

But as M87 is 55 million light years away, "This ring looks incredibly small in the sky: about 40 microarcseconds, a size comparable to the size of an orange at the Moon's surface as seen from our position on Earth, "said Bouman. .

The laws of physics would require a telescope the size of our planet to visualize it: an impossible proposition.

The EHT (Event Horizon Telescope) collaboration has spent more than 10 years building a telescope for calculating the size of the Earth combining the signals received by various telescopes working in pairs around the world.

However, as the number of locations is limited, telescopes can only pick up certain frequencies, leaving large gaps in the information.

"By analogy, you can think of the measures that the EHT does a bit like the notes of a song, each measure corresponds to the tone of a note," said Bouman.

"Observing the black hole with Event Horizon Telescope, it's a bit like listening to a song played on the piano with more than half of the broken keys."

The approach has led to many gaps that could be filled with infinite possibilities compatible with the data.

"But if your brain is still able to recognize a song played on a broken piano when there are enough keys that work, we can design algorithms to intelligently fill in missing information from the EHT to reveal the image of the underlying black hole, "she concluded. .

Avoid human prejudices

Although the images were captured in 2017, the final result had to be independently validated by four EHT teams working around the world to avoid shared human prejudices.

The four images they produced vary slightly, but they all contain the same basic structure.

"Seeing these images for the first time was truly amazing and one of the happiest memories of my life," recalled Bouman, who kept a broad smile throughout his testimony.

The last image released last April 10 was a composite of the four images that were optimized by algorithms designed to eliminate human preferences.

Bouman stated that she had started working on ISE as a postgraduate student in computer vision at MIT and that she had discovered that the problem shared striking similarities with her. the work she had done on brain imaging based on limited data provided by an MRI scanner.

"So, even though the project was well outside my main area and I had no astrophysical training, let alone black holes, I hoped to make a difference."

She also welcomed early-stage scientists from a variety of backgrounds, from post-doctorate to undergraduate, whose work was vital to the project.

"However, like black holes, many early-career scientists, who make a significant contribution, are often ignored," she said.

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© 2019 AFP