What the quest for black hole images could tell us about our universe

Hours after unveiling the first image of the black hole at the center of the Milky Way, scientists from the Harvard & Smithsonian-led team discussed its significance in an online panel. Credit: Kris Snibbe/Harvard Staff Photographer

Not so long ago, the idea of ​​photographing a black hole was as fanciful as photographing a unicorn. Now scientists have not one but two images of two different supermassive black holes – and they both look as magical as flaming donuts.

“I remember when black holes were purely theoretical,” Ellen Stofan, undersecretary for science and research at the Smithsonian and former NASA chief scientist, said during a post-revelation panel on Thursday. Moderated by Stofan, the conversation brought together four members of the Harvard-led team of scientists who, in 2019, revealed the world’s first image of a black hole – a behemoth dubbed M87 after its galaxy, Messier 87. Hours before the roundtable, the team shared a second image – a close-up of Star A Sagittarius (or Sgr A*), the black hole munching on light, cosmic debris at the center of our own galaxy, the Milky Way.

“There is no doubt now that we have seen black holes for the first time,” said Shep Doeleman, founding director of the Event Horizon Telescope Collaboration, an international team of more than 100 scientists led by the Center for Astrophysics | Harvard & Smithsonian. “This is the dawn of a new era in astronomy.”

In this new era, scientists could prove – or disprove – Einstein’s longstanding theories of gravity and relativity, find Earth 2.0, or discover a wormhole to another universe. (The latter won’t be so difficult for Doeleman, who said, cheekily, that he’s from another universe.)

Photographing a black hole is even harder than it looks. To capture images of objects so far away, “you would need an Earth-sized telescope,” said Kari Haworth, engineer and chief technology officer at the Center for Astrophysics. “We didn’t do it because it’s impossible and it would ruin a lot of people’s opinion,” she said.

Instead, researchers transformed Earth into a giant telescope by coordinating individual machines positioned in Hawaii, Chile, Mexico, Spain, France and elsewhere. Each team had to take a picture at exactly the same time. Because black holes engulf anything that gets too close, even light, they can’t be seen. But their massive gravity pulls and compresses nearby light and debris, creating a spinning gaseous whirlpool that’s bursting with energy. “Transforming falling matter into luminosity” is how Doeleman put it.

This luminosity can be seen and photographed. Some of the light that is pulled into the black hole’s gravitational field does a U-turn or loop before escaping and flying back to Earth, carrying an image of its origin. The EHT team’s final photograph is a composite of images taken by each telescope and stacked on top of each other. To combine all this data, which is light, captured at a very precise moment, the team needed to pull off another strange feat. Each telescope team froze their light, stored it on hard drives (it’s too large to send over the Internet), and airlifted it to a central location.

M87, the first black hole to get the star treatment, is about 1,000 times larger than Sagittarius’ A star and much more stable, but the images came out about the same, a knock for the EHT and Albert Einstein. Einstein theorized that black holes have only three characteristics – mass, spin and charge – and no “hair” (as astrophysicists like to call additional properties). The only difference is a slight blur in the image of the A star of Sagittarius. Our galaxy’s black hole is more restless, as restless as a toddler, and it’s harder to capture a sharp picture of something that’s constantly changing, astrophysicist Paul Tiede said. Also, there is a cosmic soup between us and the A star of Sagittarius, which obscures the images slightly. “Even considering that,” Tiede said, “I’m still struck by the similarity of these images.”

From the way black holes are described, you might expect them to be insatiable monsters, sucking up everything in space like a bathtub drain. Not exactly. Although they’re the most powerful objects in the universe – Doeleman said a black hole formed by bending the Earth in half could power Manhattan for a year – they don’t gobble up entire galaxies, but simply distort space. space-time and move objects from their destination. paths.

This is good news because the EHT team suspects that there is a a supermassive black hole at the center of each galaxy. But even with these new images, Tiede said, “We know next to nothing about them.” (When asked why black holes are donut-shaped, he replied, “Because they’re delicious.”)

“Black holes live at the frontier of our current knowledge of physics and astrophysics,” said Angelo Ricarte, who brought his pet black hole named Poe – a soft black orb with two googly eyes – to the round table. These new images are already helping Ricarte and other scientists study the strange physics of superheated gases orbiting black holes, as well as how behemoths spit out jets of these gases a million Light years in any direction. These jets, Ricarte said, could help explain “our cosmic origin story”, have profound effects on the evolution of our galaxy, or connect theories from the very large to the very small to support a theory of everything. “There are a lot of things that we still don’t fully understand in this extreme environment,” he said.

To better understand, Doeleman wants to build an even bigger telescope by placing another imaging device on a satellite orbiting Earth. He also hopes to capture something more exciting than a photo of a black hole: a movie of a black hole.

“If we could time the orbits of matter, that would be a completely different test of Einstein’s theory,” he said.

Breaking a black hole: how the EHT super-telescope works

Provided by
Harvard University

This story is published with the kind permission of Harvard Gazette, official journal of Harvard University. For more information about the university, visit Harvard.edu.

Quote: What the quest to image black holes could tell us about our universe (June 1, 2022) Retrieved June 1, 2022 from https://phys.org/news/2022-06-quest-image-black-holes-universe .html

This document is subject to copyright. Except for fair use for purposes of private study or research, no part may be reproduced without written permission. The content is provided for information only.

#quest #black #hole #images #universe

Leave a Comment

Your email address will not be published. Required fields are marked *