NASA released this new new visualization of a black hole this week, generated by astrophysicist Jeremy Schnittman, using custom software at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Schnittman’s areas of expertise include computational modeling of black hole accretion flows. That’s what you’re seeing in this visualization, the flow of material around a black hole as it might appear if you could see the hole up close (but not too close!), and from the side. Yes, black holes are black; no light can escape them. All the action is in the area immediately surrounding the hole, because the hole’s powerful gravity warps its surroundings, distorting our view, NASA said, “as if seen in a carnival mirror.” NASA explained on September 25, 2019:
The visualization simulates the appearance of a black hole where infalling matter has collected into a thin, hot structure called an accretion disk. The black hole’s extreme gravity skews light emitted by different regions of the disk, producing the misshapen appearance.
Bright knots constantly form and dissipate in the disk as magnetic fields wind and twist through the churning gas. Nearest the black hole, the gas orbits at close to the speed of light, while the outer portions spin a bit more slowly. This difference stretches and shears the bright knots, producing light and dark lanes in the disk.
Viewed from the side, the disk looks brighter on the left than it does on the right. Glowing gas on the left side of the disk moves toward us so fast that the effects of Einstein’s relativity give it a boost in brightness; the opposite happens on the right side, where gas moving away us becomes slightly dimmer. This asymmetry disappears when we see the disk exactly face on because, from that perspective, none of the material is moving along our line of sight.
Closest to the black hole, the gravitational light-bending becomes so excessive that we can see the underside of the disk as a bright ring of light seemingly outlining the black hole. This so-called “photon ring” is composed of multiple rings, which grow progressively fainter and thinner, from light that has circled the black hole two, three, or even more times before escaping to reach our eyes. Because the black hole modeled in this visualization is spherical, the photon ring looks nearly circular and identical from any viewing angle. Inside the photon ring is the black hole’s shadow, an area roughly twice the size of the event horizon — its point of no return.
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Simulations and movies like these really help us visualize what Einstein meant when he said that gravity warps the fabric of space and time. Until very recently, these visualizations were limited to our imagination and computer programs. I never thought that it would be possible to see a real black hole.
Yet – as many recall – on April 10 of this year, the Event Horizon Telescope team released the first-ever image of a black hole’s shadow using radio observations of the heart of the galaxy M87.
Bottom line: For decades, astronomical theorists have told us that a black hole’s powerful gravity would warp the space around it. This new visualization from NASA’s Goddard Space Flight Center is the best yet at showing exactly how.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.