Physicists Used Einstein’s Relativity To Successfully Predict A Supernova Explosion
“When the lens and a background source align in a particular fashion, quadruple images will result. With slightly different light-travel paths, the brightness and arrival time of each image is unique. In November 2014, a quadruply-lensed supernova was observed, showcasing exactly this type of alignment. Although a single galaxy caused the quadruple image, that galaxy was part of a huge galaxy cluster, exhibiting its own strong lensing effects. Elsewhere in the cluster, two additional images of the same galaxy also appear.”
We normally think of light traveling in a straight line, but that’s only true if your space is flat. In the real Universe, mass and matter not only exist, but clump together into massive structures like galaxies, quasars, and galaxy clusters. When a background source of light passes through these foreground masses, the light can get bent and distorted into multiple images that are magnified and arrive at slightly different times. If an event occurs in one such image, we can predict, based on General Relativity, cluster dynamics, and dark matter, when that event will appear in the other images.