 This same light bending leads to the warping of light from distant galaxies as the light encounters supermassive galaxies on their path to us. This is called gravitational lensing. Here's a clip that shows how this lensing works on a grand scale. A distant galaxy would be seen here on Earth directly if there were no intervening massive cluster to bend the light. But with such a cluster the light from the distant galaxy gets bent into rings and arcs to continue on to the Earth. This is Able 1689, 2.2 billion light years away. It's one of the most massive galaxy clusters known. The gravity of its trillion stars plus dark matter acts like a 2 million light year wide lens in space. And here's another cluster, 5.7 billion light years away. It's the latest from Hubble on gravitational lensing released in late 2015. These foreground galaxy clusters are magnifying the light from the faint galaxies that lie far behind the clusters themselves. These faint lensed galaxies are around 12 billion light years away. It's the gravitational lensing that allows us to see that far back in time. Without the magnification these galaxies would be invisible for us.