Artist’s impression of massive object distorting spacetime

Einstein’s general theory of relativity predicts that objects deform spacetime, causing any light that passes by to be deflected. This effect is only noticeable for very massive objects. One result of this deformation of spacetime is that light from distant sources is deflected around a massive intervening object, such as a galaxy. ESO 325-G004 is the large haze of light in the centre of the screen which is deforming light from the background galaxies.