How Does Light Ripple Through Deep Space?

We previously discussed how gravity bends light around various cosmic bodies, but what happens at the boundaries that determine exactly what we see as an observer? https://emergentbeacon.com/videos/critical-curves This video is an addendum to "What Is This Cosmic Mirage?" https://youtu.be/yCHYmlwjUcI EDITOR'S NOTE  * caustic & critical curve diagram adjustments at 6:14:  The green and yellow dots were the same color in the original diagram; they could have represented a double-lensed source, but that wasn’t mentioned, so I’ve separated them (maybe naively) under the assumption that the same color was in error. I also added a small dark blue dot in the inner critical curve, which was not originally present, but I believe should have been as consistent with the diagrams at 12:18. SUPPORT  You can directly support the show at  https://patreon.com/emergentbeacon  Music from this video can be streamed or purchased  https://emergentbeacon.com/music/critical-curves CITATIONS  1. 2019, Scientists Simulate a Black Hole in a Water Tank   https://phys.org/news/2019-02-scientists-simulate-black-hole-tank.html  2. 1986, Fermat’s Principle, Caustics, and the Classification of Gravitational Lens Images   http://articles.adsabs.harvard.edu//full/1986ApJ...310..568B/0000568.000.html  3. 2003, The Basics of Lensing   https://arxiv.org/abs/astro-ph/0304438  4. 2017, Gravy: A Ray-Traced Gravitational Lens Demo   https://github.com/portsmouth/gravy  5. 2014, Java Lens Simulation   https://compadre.org/osp/items/detail.cfm?ID=11451   (requires download to use)  6. 2014, Galaxy Cluster Simple Lens   https://slowe.github.io/LensToy   https://github.com/slowe/LensToy  7. 2021, WebGL Lens with Caustics   https://eb.v32.dev/lensing-sim/  8. 2015, Introduction to Gravitational Lensing (PDF)   https://www.ita.uni-heidelberg.de/~jmerten/misc/meneghetti_lensing.pdf  9. 2018, Diffraction of Electromagnetic Waves in the Gravitational Field of the Sun   https://arxiv.org/abs/1704.06824  10. 2019, The Legacy of Einstein's Eclipse, Gravitational Lensing   https://arxiv.org/abs/1912.07674  11. 2019, Building the 100-inch Telescope   https://mtwilson.edu/building-the-100-inch-telescope/  12. 2015, The Amateur Who Helped Einstein See the Light   https://sciencenews.org/blog/context/amateur-who-helped-einstein-see-light MEDIA  i1. 2014, twin quasar and surrounding area captured by Hubble   https://esahubble.org/images/potw1403a/ CHAPTERS  0:00 welcome  0:24 pronunciation corrections  1:32 simulation with water vortex  2:59 thin lens approximation  4:09 twin quasars  4:57 caustics and critical curves  10:31 three interactive demos  12:32 focal line  14:28 early solar eclipse expeditions  16:11 deleted scene: scratched eye  16:49 deleted scene: hooker telescope debut  18:30 the einstein quote  22:12 closing thoughts CREW  brandt hughes: research, host, cam op, audio engineer, music prod, editor SOCIALS  gaming: https://youtube.com/@BrandtHughes  bluesky: https://bsky.app/profile/brandthughes.bsky.social  discord: https://discord.emergentbeacon.com  patreon: https://patreon.emergentbeacon.com