When scientists announced in a co-ordinated press meet and released the first ever image of the black hole yesterday, the world was left in awe by the beauty of the ‘ring of fire’.
A pale blurred hot yellowish hue surrounding a black dot; humanity just looked into the very first image of the black hole. Soon enough, millions took on to social media to share the groundbreaking photo and eventually, some started asking “what’s the big deal about this image?” For starters, its important to know about black holes.
* What are black holes?
A black hole is a region of space where even light cannot escape. They are not empty but instead consist of a huge amount of matter packed densely into a small area giving it an immense gravitational pull. There is a region of space beyond the black hole called the event horizon. This is a ‘point of no return’, beyond which it is impossible to escape the gravitational effects of the black hole. Black holes were predicted by Einstein’s theory of general relativity
* The initial seed
Professor Heino Falcke, of Radboud University in the Netherlands had the idea for the project when he was a PhD student in 1993. Back then, the prospect of photographing a black hole was impossible. But he was the first to realise that a certain type of radio emission would be generated close to and around the black hole, which would be powerful enough to be detected by telescopes on Earth. He also recalled reading a scientific paper from 1973 that suggested that because of their enormous gravity, black holes appear 2.5 times larger than they actually are.
These two factors suddenly made the impossible, possible. After arguing his case for 20 years, Falcke persuaded the European Research Council to fund the project. The National Science Foundation and agencies in East Asia then joined in to bankroll the project, pitching in more than £40m.
* Earth-sized telescopes used
No single telescope is powerful enough to photograph the black hole. Professor Sheperd Doeleman of the Harvard-Smithsonian Centre for Astrophysics led a project to set up a network of eight linked telescopes, basically forming a telescopes the size of the earth. Together, they formed the Event Horizon Telescope and can be thought of as a planet-sized array of dishes. Each is located high up at a variety of exotic sites, including on volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, in the Atacama Desert of Chile, and in Antarctica.
A team of 200 scientists pointed the networked telescopes towards M87 and scanned its heart over a period of 10 days. The information they gathered was too much to be sent across the internet. Instead, the data was stored on hundreds of hard drives that were flown to a central processing centres in Boston, US, and Bonn, Germany, to assemble the information.
*History in the making
The first ever image of a black hole measures 40 billion km across, about three million times the size of the Earth. The black hole is 500 million trillion km away. Falcke told media that the black hole was found in a galaxy called M87. “What we see is larger than the size of our entire Solar System,” he said. “It has a mass 6.5 billion times that of the Sun. And it is one of the heaviest black holes that we think exists. It is an absolute monster, the heavyweight champion of black holes in the Universe.” The bright halo is caused by superheated gas falling into the hole. The light is brighter than all the billions of other stars in the galaxy combined which is why it can be seen at such distance from Earth.
* What next?
The first image will enable researchers to learn more about these mysterious objects. They will be keen to look out for ways in which the black hole departs from what’s expected in physics. No-one really knows how the bright ring around the hole is created. Researchers will also learn about what may happen when an object falls into a black hole.