Any object with mass warps space-time but this only really becomes apparent for very dense objects, like stars, galaxy clusters, and black holes. Last year for Black Hole Week, NASA released an incredible visualization of how the extreme gravity of a black hole distorts and redirects our view of the light coming from the accretion disk around it. For this year's Black Hole Week, NASA has gone one better and released a stunning visualization of how this effect would appear if there were two orbiting supermassive black holes hundreds of million times heavier than the Sun.
The visualization was created by the same team using the Discover supercomputer and shows the real physics of space-time distortions due to extreme gravity. The two black holes are shown with accretion disks, a donut of gas and dust and material that surrounds the black hole, from which they feed. In the video, we see the black holes orbiting each other from above, to begin with. The accretion disks are colored red and blue to clearly distinguish between the two when things get weird and our view of their orbit becomes edge-on.
“We’re seeing two supermassive black holes, a larger one with 200 million solar masses and a smaller companion weighing half as much,” Jeremy Schnittman, creator of the visualization, explained in a statement. “These are the kinds of black hole binary systems where we think both members could maintain accretion disks lasting millions of years.”
The edge-on view when the black holes are “eclipsing” each other is certainly the most striking, with the images morphing from one instant to the next as the gravity from the larger black hole warps our view of the light from the smaller one. It also shows a subtle phenomenon called relativistic aberration, where the objects appear smaller the closer they get to us and larger further away.
The views from above reveal some peculiar gravitational effects, too. “A striking aspect of this new visualization is the self-similar nature of the images produced by gravitational lensing,” Schnittman explained. “Zooming into each black hole reveals multiple, increasingly distorted images of its partner.”
On a regular computer, this visualization would have taken a decade to complete. Using just 2,580 of Discover's 129,000 processors (around 2 percent) it only took a day. Creating this visualization isn't just to see what orbiting black holes would look like in a funhouse mirror though. Because it is so hard to image a black hole – by their very nature light can't escape them – simulations like this help us understand what we can't see but know is occurring around black holes or visualize our best theories.
Astronomers hope in the not too distant future they will be able to detect the gravitational waves produced when two supermassive black holes orbiting each other like in this video finally merge.