The DP-3T algorithm for contact tracing (via Nicky Case) @3blue1brown

3Blue1Brown | The DP-3T algorithm for contact tracing (via Nicky Case) @3blue1brown | Uploaded 4 years ago | Updated 9 minutes ago
Though many contact tracing apps involve location tracking, they don’t have to.
This is a video adaptation of a post by Nicky Case: ncase.me/contact-tracing
New post by Nicky on COVID-19: ncase.me/covid-19
Consider supporting his work: patreon.com/ncase
Supporters of this video: 3b1b.co/ctracing-thanks

DP-3T Whitepaper:
github.com/DP-3T/documents/blob/master/DP3T%20White%20Paper.pdf

Full repo:
github.com/DP-3T

Where did the number 60% come from?
science.sciencemag.org/content/early/2020/04/09/science.abb6936

The specific figure is Figure 3, the last panel showing instant contact tracing (with an app). It shows what combination of % (symptomatic) cases isolated & % (pre/a-symptomatic) contacts quarantined would contain the virus or not.

Mental health resources (copied from a John Green video, since he knows what he's doing):
National Suicide Prevention Lifeline: 1-800-273-TALK (8255)
I know it can be scary to make a phone call, but people are nice, I promise.
Substance Abuse and Mental Health Administration helpline: 1-800-662-HELP (4357)
The Trevor Project: 866-488-7386
International helplines: togetherweare-strong.tumblr.com/helpline

Mental Health Resource list and links: http://activeminds.org
The Anxiety and Depression Association of America: http://www.adaa.org
Mental Health screening tools: screening.mhanational.org/screening-tools
Mind: http://mind.org.uk/information-support

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Music by Vincent Rubinetti.
Download the music on Bandcamp:
vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown

Stream the music on Spotify:
open.spotify.com/album/1dVyjwS8FBqXhRunaG5W5u

If you want to contribute translated subtitles or to help review those that have already been made by others and need approval, you can click the gear icon in the video and go to subtitles/cc, then "add subtitles/cc". I really appreciate those who do this, as it helps make the lessons accessible to more people.

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3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe: http://3b1b.co/subscribe

Various social media stuffs:
Website: 3blue1brown.com
Twitter: twitter.com/3blue1brown
Reddit: reddit.com/r/3blue1brown
Instagram: instagram.com/3blue1brown_animations
Patreon: patreon.com/3blue1brown
Facebook: facebook.com/3blue1brown

Holograms are wild (link above explains how this works)

Why do prime numbers make these spirals? | Dirichlet’s theorem and pi approximations

$How are holograms possible? 3d scenes on 2d film, and a diffraction lesson along the way. Instead of sponsored ad reads, these lessons are funded directly by viewers: https://3b1b.co/support 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 didnt properly double-check how we got there. 2) In the end, I referenced treating |R^2| as some real number, so that its 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 its a wave with relatively constant magnitude across the film. Gabors Nobel Prize lecture: https://www.nobelprize.org/uploads/2018/06/gabor-lecture.pdf A few resources we found helpful for this video Seeing the Light, by Falk, Brill, and Stork https://amzn.to/3Ngdiqh Practical Holography, by Saxby and Zarcharovas https://amzn.to/3ZR2MNN Principles of Holography by Howard Smith https://amzn.to/3ZOihFZ 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 These animations are largely made using a custom Python library, manim. See the FAQ comments here: https://3b1b.co/faq#manim https://github.com/3b1b/manim https://github.com/ManimCommunity/manim/ All code for specific videos is visible here: https://github.com/3b1b/videos/ The music is by Vincent Rubinetti. https://www.vincentrubinetti.com https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown https://open.spotify.com/album/1dVyjwS8FBqXhRunaG5W5u 3blue1brown is a channel about animating math, in all senses of the word animate. If youre reading the bottom of a video description, Im guessing youre 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: https://3blue1brown.substack.com Twitter: https://twitter.com/3blue1brown Instagram: https://www.instagram.com/3blue1brown Reddit: https://www.reddit.com/r/3blue1brown Facebook: https://www.facebook.com/3blue1brown Patreon: https://patreon.com/3blue1brown Website: https://www.3blue1brown.com$

$e to the pi i, a nontraditional take (old version) Wait! Theres an improved version: https://youtu.be/mvmuCPvRoWQ Also, for the calculus-savvy, youll prefer this one: https://youtu.be/v0YEaeIClKY Home page: https://www.3blue1brown.com/ The enigmatic equation e^{pi i} = -1 is usually explained using Taylors formula during a calculus class. This video offers a different perspective, which involves thinking about numbers as actions, and about e^x as something which turns one action into another. For more information on viewing exponential functions in this new light, check out this article: http://goo.gl/LPyc4R Music: Wyoming 307 by Time For Three, http://www.tf3.com/$

What does area have to do with slope? | Chapter 9, Essence of calculus

But why is a spheres surface area four times its shadow?

How prisms work (video linked above shows why light slows down)

The most unexpected answer to a counting puzzle