On Wednesday 10th April 2019, astronomers from Chile, Shanghai, Japan, Tapei and the United States of America revealed the first photograph of a black hole. The black hole in question is at the heart of the Messier 87 galaxy, 55 million light years from Earth. It measures 40 billion km across- three million times the size of Earth, and 6.5 billion times the mass of our Sun. Not only is the photograph an amazing feat of human ingenuity but it also confirms Einstein’s theory of General Relativity: gravity is the consequence of the warping of space-time.
This is not just a matter of confirming predictions, however, this image provides exciting new avenues for scientists to refine their knowledge of black holes, by examining their spin and their magnetic fields. It also means that we may see pictures of their second target, Saggitarius A: the black hole at the centre of our galaxy. With this recent success, the hope is that their next discovery will be happening “very soon”. Our generation has now witnessed the transformation from “mathematical concept” to a “physical entity” and scientists are rightly on the edge of their lab stools with anticipation.
The picture itself was captured by the Event Horizon Telescope (EHT), a project involving over 200 scientists from 60 different institutes in 20 different countries working from 8 telescopes. The project has been developing for over a decade to link telescopes around the globe to make a “virtual dish” the size of our entire planet. By linking the telescopes, they were able to achieve the highest angular resolution possible from the surface of the Earth; in context, the EHT would enable us to read a newspaper in New York from a cafe in Paris!
The amount of data collected from all of the telescopes was so enormous that it had to be physically shipped to the MIT via half a tonne of hard drives. Although the results were invaluable, the practicality of the research posed a huge problem; the data not only needed to be brought together, but also required all noise caused by things such as atmospheric humidity to be filtered out in order to create an image; it required a mathematical process to sort through the data quickly and efficiently. MIT graduate, Dr Katie Bouman devised the algorithm CHIRP (Continuous High-resolution Image Reconstruction) that the scientists at the EHT were able to use to fill in the gaps that were left by the their eight telescopes across the world. It is thanks to her efforts that we have been able to “see the unseeable“.
This is a landmark in Science that will transform and enhance our understanding of black holes for decades and centuries to come. The work of the late Professor Stephen Hawking was groundbreaking in his time, and will continue to inform the hypothesis of future generations, but this remarkable discovery has only proven his work, and would have left him “blown away”
We do not know exactly what the future of the astrophysics holds, but with this new discovery, it is certain to be an exciting one!