Gravitational Lensing
Gravitational lensing is a phenomenon in which light from a distant object is bent and distorted by the gravitational pull of a massive object, such as a galaxy or black hole, that lies between the observer and the source. This distortion can cause the distant object to appear magnified, stretched, or even multiply imaged. Gravitational lensing is a key tool in studying the distribution of dark matter in the universe and can provide valuable insights into the properties of distant galaxies and the nature of spacetime itself.