https://www.vice.com/en_us/article/7kxk99/scientists-plan-to-measure-distorted-time-in-deep-space-to-probe-reality

Scientists want to measure the distortion of time in ancient faraway galaxies in order to solve fundamental mysteries about our reality, including the potential existence of a “fifth force” beyond established physics, reports a new study. 

By peering at galaxies located billions of light years from Earth, researchers hope to spot signs of an effect called gravitational redshift, wherein light becomes redder after escaping the gravitational pull of massive objects. This redshifted light contains clues about how the gravitational fields of massive objects warp time, which could constrain a host of unanswered questions about our universe.