One of the strangest predictions of general relativity is that gravity can deflect the path of light. The effect was first observed by Arthur Eddington in 1919. While the bending effect of the Sun is small, near a black hole light deflection can be significant. So significant that you need a powerful supercomputer to calculate how light will behave.
Recently the NASA Goddard Media Studios released a few videos showing us how a binary black hole system might look under gravitational lensing. The simulation traces the paths of light coming from the accretion disks of two close-orbiting black holes. One with a mass of 200 million Sun, the other with half that mass. The simulation was run on the Discover supercomputer at the NASA Center for Climate Simulation and took about a day to complete.
Check out NASA Goddard’s video to see the latest simulation.
This new simulation takes into account some of the more subtle effects. For example, near a rotating black hole, light coming from the side rotating toward us will appear brighter, while light from the side rotating away from us would appear dimmer. This effect is known as Doppler boosting. Another strange effect is known as ...