Gravitational Lensing

In this segment of the “How Fast Is It” video book, we cover gravitational lensing. First, we illustrate how the light is bent, followed by some Einstein Ring examples. We then cover the lens itself: how it magnifies; how it distorts; and how images are mapped back to the source celestial object. We also cover critical curves that can magnify an object by thousands of times. We use Abell 68 and MACS 1206 as examples. We cover flickering quasars and how they can be used to calculate the Hubble constant. We follow that with multiple Type 1a supernovae image timings that can also be used to calculate the Hubble constant. We use the supernova Refsdal with its Einstein Cross as an example. We then cover lensing galaxies like Hamilton’s Object, Starburst Arc and Abell 1689-zD1.   We finish with lensing stars namely Icarus and Earendel.