Hypnotic New NASA Visualization Probes the Light-Bending Dance of Binary Black Holes

Supermassive Black Hole With Smaller Black Hole

In this frame from the new visualization, a supermassive black hole weighing 200 million solar masses lies in the foreground. Its gravity distorts light from the accretion disk of a smaller companion black hole almost directly behind it, creating this surreal view. Different colors for the accretion disks make it easier to track the contributions of each one. Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell

A pair of orbiting black holes millions of times the Sun’s mass perform a hypnotic pas de deux in a new NASA visualization. The movie traces how the black holes distort and redirect light emanating from the maelstrom of hot gas – called an accretion disk – that surrounds each one.

Viewed from near the orbital plane, each accretion disk takes on a characteristic double-humped look. But as one passes in front of the other, the gravity of the foreground black hole transforms its partner into a rapidly changing sequence of arcs. These distortions play out as light from both disks navigates the tangled fabric of space and time near the black holes.


Explore how the extreme gravity of two orbiting supermassive black holes distorts our view. In this visualization, disks of bright, hot, churning gas encircle both black holes, shown in red and blue to better track the light source. The red disk orbits the larger black hole, which weighs 200 million times the mass of our Sun, while its smaller blue companion weighs half as much. Zooming into each black hole reveals multiple, increasingly warped images of its partner. Watch to learn more. Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell

“We’re seeing two supermassive black holes, a larger one with 200 million solar masses and a smaller companion weighing half as much,” said Jeremy Schnittman, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, who created the visualization. “These are the kinds of black hole binary systems where we think both members could maintain accretion disks lasting millions of years.”  

The accretion disks have different colors, red and blue, to make it easier to track the light sources, but the choice also reflects reality. Hotter gas gives off light closer to the blue end of the spectrum, and material orbiting smaller black holes experiences stronger gravitational effects that produce higher temperatures. For these masses, both accretion disks would actually emit most of their light in the UV, with the blue disk reaching a slightly higher temperature.

Warped View Binary Black Holes Details

This image shows the warped view of a larger supermassive black hole (red disk) when it passes seen almost directly behind a companion black hole (blue disk) with half its mass. The gravity of the foreground black hole transforms its partner into a surreal collection of arcs. Insets highlight areas where one black hole produces a complete but distorted image of the other. Light from the accretion disks produces these self-similar images as it travels through the tangled fabric of space and time near both black holes. Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell

Visualizations like this help scientists picture the fascinating consequences of extreme gravity’s funhouse mirror. The new video doubles down on an earlier one Schnittman produced showing a solitary black hole from various angles.

Seen nearly edgewise, the accretion disks look noticeably brighter on one side. Gravitational distortion alters the paths of light coming from different parts of the disks, producing the warped image. The rapid motion of gas near the black hole modifies the disk’s luminosity through a phenomenon called Doppler boosting – an effect of Einstein’s relativity theory that brightens the side rotating toward the viewer and dims the side spinning away.

The visualization also shows a more subtle phenomenon called relativistic aberration. The black holes appear smaller as they approach the viewer and larger when moving away.

Views of Binary Black Holes

A face-on view of the system highlights the smaller black hole’s distorted image (inset) of its bigger companion. To reach the camera, the smaller black hole must bend light from its red companion by 90 degrees. The accretion disk of this secondary image appears as a line, which means we’re seeing an edge-on view of the red companion – while also simultaneously seeing it from above. A secondary image of the blue disk also forms just outside the bright ring of light nearest the larger black hole, too. Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell

These effects disappear when viewing the system from above, but new features emerge. Both black holes produce small images of their partners that circle around them each orbit. Looking closer, it’s clear that these images are actually edge-on views. To produce them, light from the black holes must be redirected by 90 degrees, which means we’re observing the black holes from two different perspectives – face on and edge on – at the same time.

“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.”

Warped View Binary Black Holes

This image shows the warped view of a larger supermassive black hole (red disk) when it passes almost directly behind a companion black hole (blue disk) with half its mass. The gravity of the foreground black hole transforms its partner into a surreal collection of arcs. These distortions play out as light from the accretion disks navigates the tangled fabric of space and time near the black holes. Credit: NASA’s Goddard Space Flight Center/Jeremy Schnittman and Brian P. Powell

Schnittman created the visualization by computing the path taken by light rays from the accretion disks as they made their way through the warped space-time around the black holes. On a modern desktop computer, the calculations needed to make the movie frames would have taken about a decade. So Schnittman teamed up with Goddard data scientist Brian P. Powell to use the Discover supercomputer at the NASA Center for Climate Simulation. Using just 2% of Discover’s 129,000 processors, these computations took about a day.

Astronomers expect that, in the not-too-distant future, they’ll be able to detect gravitational waves – ripples in space-time – produced when two supermassive black holes in a system much like the one Schnittman depicted spiral together and merge.

8 Comments on "Hypnotic New NASA Visualization Probes the Light-Bending Dance of Binary Black Holes"

  1. … what would happen if one observes three of those, four, five, six, seven, …

  2. Utter nonsense.

    Black holes are not 2D in shape they are 3D.

    Why people always show 2D discs is beyond me.

    They pull in from all directions on the X, Y & Z planes.
    Think of light from the sun and reverse it!

    Wish news would not show this illusion, its pure nonsense.

    • Yes the hole itself is 3 dimensional, but you can’t see it because no light can escape the event horizon of nature’s most perfect sphere. If no light can escape, no light can reflect its shape.

      What we’re looking at in the simulation is the accretion disk, matter and energy which spirals *around* the event horizon, and which gravity formed into a disk the same way rings around planets are formed, the same way our galaxy is a spiral ‘disk’.

      Yes matter and energy are falling into the black hole from all directions, but the only light that reaches our eyes (or instruments) are the photons that sling off from the accretion disk fast enough to escape. Everything else surrounding the black hole succumbs to gravity.

      Gravitational lensing is the same reason the center of our galaxy appears as a bright round blob when in fact there’s a supermassive black hole (or two) at the center. Light appears to surround the center of our galaxy, as if at the center there were a hot hot super-sun. That’s impossible, anything that massive collapses into a black hole. That light exists in a disk around the supermassive black hole at the center of the galaxy.
      We’re looking at the center from the edge, so that disk is being lensed into what we perceive as a sphere. Everything that was actually above or below our galaxy long ago fell into the supermassive black hole.

      Flat earth is theory is bee ess, but accretion disks are real!

    • Torbjörn Larsson | April 18, 2021 at 6:01 am | Reply

      How can it be nonsense when it is a simulation that is faithful to the physics – “computing the path taken by light rays from the accretion disks as they made their way through the warped space-time around the black holes” – and “help scientists picture the fascinating consequences of extreme gravity’s funhouse mirror”?

      I’m not sure what 2D aspect your are speaking of. The gravity and photon trajectory simulation is obviously in 3D, albeit the video projection is also obviously down to 2D. And the accretion ring is very thin in comparison to the black hole size.

      For example, 100 million solar masses supermassive black holes – about 10 times more massive than our own Sgr* – have event horizon diameters of about 1 au [ https://en.wikipedia.org/wiki/Sagittarius_A* ; event horizon radius is proprtional to the black hole mass]. Their innermost stable orbit of the opening is 3 times as wide as that. But the accretion ring thickness typically less than 1/10 of that going out to distances 100 times that [“Exploring the Effects of Disk Thickness on the Black Hole Reflection Spectrum”, Corbin Taylor1 and Christopher S. Reynolds, The Astrophysical Journal, 2018; fig 2]. The typical ring model is described as “the standard razor-thin case”.

      It is admittedly a first proof-of-principle simulation and is also simplified to show the dominant physics, but to call it “nonsense” is nonsensical. If they miss any effects from an optically thick accretion disk, simulations of such disks will eventually show that. Meanwhile we can appreciate the scientific progress and the sheer beauty of it!

  3. The only issue is that due to the Doppler effect, the black hole will not be monochromatic.
    As a result, if we look at one black hole, we should see light moving towards us in blue and light moving away from us in red.
    When we have a binary black hole, the color mixture intensifies.
    The amount of red and blue (and colors in between) seen by the observer should also be determined by the observer’s frame of reference to the binary’s more massive black hole.

    • Torbjörn Larsson | April 18, 2021 at 6:06 am | Reply

      The text explains that it is a simplification, likely as much because it is early days and computer demanding anyway as to simplify for the viewer.

      But the video goes into the gravity zoom effects and IIRC the relativistic (including Doppler) dimming that must complicate the brightness simulation. So they are getting there.

    • Torbjörn Larsson | April 18, 2021 at 6:06 am | Reply

      Also, nice catch!

Leave a Reply to Torbjörn Larsson Cancel reply

Email address is optional. If provided, your email will not be published or shared.