the first direct visual evidence of a supermassive black hole and its shadow.
The image reveals the black hole at the center of Messier 87, a massive galaxy in the nearby Virgo galaxy cluster. This black hole resides 55 million light-years from Earth and has a mass 6.5 billion times that of the Sun.
The EHT links telescopes around the globe to form an Earth-sized virtual telescope with unprecedented sensitivity and resolution. The EHT is the result of years of international collaboration, and offers scientists a new way to study the most extreme objects in the Universe predicted by Einstein’s general relativity during the centennial year of the historic experiment that first confirmed the theory.
Each telescope of the EHT produced enormous amounts of data — roughly 350 terabytes per day — which was stored on high-performance helium-filled hard drives. These data were flown to highly specialised supercomputers — known as correlators — at the Max Planck Institute for Radio Astronomy and MIT Haystack Observatory to be combined.
Beyond confirming the existence of the black hole, EHT tells us that all its features of the hole match the predictions of Einstein’s general theory of relativity. The object is rotating clockwise. A black hole, unless a hole in your jeans, spins. This rotation drives the jets that the hole ejects from its environs into deep space. Interestingly, the image from the telescope is asymmetric, which might be a further clue to the spin and mass.
Looking at a black hole is what the Event Horizon Telescope has done for the past 12 years.
The Event Horizon Telescope (EHT) is not less remarkable than the objects it observes. With a collaboration of 200 people, the EHT uses not a single telescope, but a global network of nine telescopes. Its sites, from Greenland to the South Pole and from Hawaii to the French Alps, act in concert as one. Together, the collaboration commands a telescope the size of planet Earth, staring at a tiny patch in the northern sky that contains the Messier-87 black hole.
Black holes bend light so much that it can wrap around the horizon multiple times. The resulting image is too complicated to capture in simple equations.
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The experimental challenge is formidable. The network’s telescopes must synchronize their data-taking using atomic clocks. Weather conditions must be favorable at all locations simultaneously. Once recorded, the amount of data is so staggeringly large, it must be shipped on hard disk to a central location for processing.
The EHT’s observations agree with expectation. But this result is more than just another triumph of Einstein’s theory of general relativity. It is also a triumph of the astronomers’ resourcefulness. They joined hands and brains to achieve what they could not have done separately.
it wasn’t until 1978 that physicists got a first glimpse of what a black hole would actually look like. In that year, the French astrophysicist Jean-Pierre Luminet programmed the calculation on an IBM 7040 using punchcards. He drew the image by hand.
“We had to convince all of these observatories that the science we wanted to do was good enough that they would let us come in and rummage around in some of their sensitive insides,”
The Atacama Large Millimeter Array in Chile took six years and a lot of negotiations to receive all the necessary upgrades.
“It turns out that the Internet is just too slow to transfer all of our data,” says Doeleman. “All the data that we recorded at the South Pole in April 2017 would have taken about twenty five years to get back using the Internet.”
“We’re confident that we can take the next step and move from still images to making movies of black holes,” he says. “And we feel there are no logistical problems that would prevent us from doing that over the next decade.”
Given the pressure that many schools are under, exploration and play are often discouraged because they seem like “inefficient” modes of learning. Under capitalism, inefficiency is never framed positively—it’s considered wasteful. But I believe that learning is fundamentally inefficient, and that it shouldn’t be dictated by capitalist imperatives. Learning is naturally circuitous, adventitious, sort of a chance operation
Many scholars are doing some long-overdue grappling with the white, elitist legacy of the discipline since the 19th century. Scholars of antiquity have everything to gain from working to dismantle that legacy, and inviting engagement with the ancient world based not on racist or elitist identity politics, but on critical thinking, open-minded curiosity, and joy.
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