How are holograms possible? | Optics puzzles 5

3d scenes on 2d film, and a diffraction lesson along the way. Instead of sponsored ad reads, these lessons are funded directly by viewers: An equally valuable form of support is to share the videos. Thanks to everyone who helped with this project: Paul Dancstep, for help writing, and for all the 3d modeling Craig Newswanger and Sally Weber, for making the central hologram shown Kurt Bruns, for the artwork of Dennis Gabor Phoebe Tooke, Wayne Grim, and Rick Danielson, for filming at the exploratorium Quinn Brodsky and Mithuna Yoganathan, for footage of lasers through diffraction gratings Vince Rubinetti, for writing the music Cliff Stoll for the Klein Bottle Hologram credits (thanks to the commenter tovedelenius1228): The Microscope is by Walter Spierings, 1984 Lucy in a Tin Hat is by Patrick Keown Boyd, 1988 The Star Wars-themed Direct-Write Digital Holograms were produced by Zebra Imaging. The ’Shakespeare’ embossed animated integral hologram was made by Applied Holographics. Mathematical corrections: 1) In the analysis for the distance between zone plate fringes, we should do a Taylor approximation about d=0, not about x=0. If you this right, the result at the bottom will look like x / sqrt(L^2 x^2), which conveniently cancels out another (much sillier) mistake, which is how x / L in this case is not sin(theta’), but tan(theta’). Thanks to those who spotted that, I guess I must have been happy enough to see the desired sin(theta’) at the end that I didn’t properly double-check how we got there. 2) In the end, I referenced treating |R^2| as “some real number“, so that it’s only scaling O. This only makes sense to do because the amplitude of R is constant. Or at least, it varies only very slowly around a point. In this way, what I say a few moments later about making no assumptions about R is not quite right, we do need to assume it’s a wave with relatively constant magnitude across the film. Gabor’s Nobel Prize lecture: A few resources we found helpful for this video Seeing the Light, by Falk, Brill, and Stork Practical Holography, by Saxby and Zarcharovas Principles of Holography by Howard Smith Timestamps 0:00 - What is a Hologram? 3:28 - The recording process 11:45 - The simplest hologram 17:12 - Diffraction gratings 25:15 - Reconstructing the simplest hologram 28:24 - Conjugate image 31:11 - More complex scenes 35:58 - The bigger picture of holography 38:27 - The formal explanation SEV1: ------------------ These animations are largely made using a custom Python library, manim. See the FAQ comments here: #manim All code for specific videos is visible here: The music is by Vincent Rubinetti. ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. If you’re reading the bottom of a video description, I’m guessing you’re more interested than the average viewer in lessons here. It would mean a lot to me if you chose to stay up to date on new ones, either by subscribing here on YouTube or otherwise following on whichever platform below you check most regularly. Mailing list: Twitter: Instagram: Reddit: Facebook: Patreon: Website: