Does light take all possible paths at the same time



We’re incredibly grateful to Prof. David Kaiser, Prof. Steven Strogatz, Prof. Geraint F. Lewis, Elba Alonso-Monsalve, Prof. Christopher S. Baird, Prof. Anthony Bloch, and Prof. Stephen Bartlett for their invaluable contributions to this video.

A special thanks to Mahesh Shenoy from FloatHeadPhysics for his help with this video. Check out his excellent intuitive video on the UV Catastrophe here (Sep 2024): https://www.youtube.com/watch?v=ALEDjjAVZSY

▀▀▀
0:00 What path does light travel?
2:40 Black Body Radiation
6:47 How did Planck solve the ultraviolet catastrophe?
9:42 The Quantum of Action
13:25 De Broglie’s Hypothesis
15:16 The Double Slit Experiment
20:00 How Feynman Did Quantum Mechanics
25:01 Proof That Light Takes Every Path
31:16 The Theory of Everything

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Sign up to our Patreon to watch the Q&A for free: https://www.patreon.com/c/veritasium

Try Snatoms! A molecular modelling kit I invented where the atoms snap together.
https://ve42.co/SnatomsV

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References:
Armin Hermann (Nov 1974). The Genesis of Quantum Theory (1899-1913). - https://ve42.co/genquanttheor
Richard P. Feynman (1985). QED The Strange Theory of Light and Matter. - https://ve42.co/qed
A fantastic book on the history of the Principle of Least Action: Rojo, A. and Bloch, A. The
Principle of Least Action: History and Physics. - https://ve42.co/Bloch2018
Coopersmith, J. (2017). The lazy universe: an introduction to the principle of least action. Oxford University Press. - https://ve42.co/LazyU
PBS Space Time. (Nov 2021) - https://www.youtube.com/watch?v=Q_CQDSlmboA
Sabine Hossenfelder. (May 2022) - https://www.youtube.com/watch?v=A0da8TEeaeE
Max Planck (1901). On the Law of Distribution of Energy in the Normal Spectrum. Annalen der Physik - https://ve42.co/lawdistenergy
Paul Ehrenfest (1911). Welche Züge der Lichtquantenhypothese spielen in der Theorie der Wärmestrahlung eine wesentliche Rolle?. Wiley Online Library - https://ve42.co/quantthermrad
Nils-Erik Bomark and Reidun Renstrøm (Aug 2023). The Ultraviolet myth. Proceedings of Science - https://ve42.co/uvmyth
Planck's law. In Wikipedia - https://ve42.co/planckslaw
PBS Space Time. (Jul 2017). - https://www.youtube.com/watch?v=vSFRN-ymfgE&t=10s
Einstein and The Photoelectric Effect. (Jan 2005) via APS News - https://ve42.co/einsteinphotoelec
Louis de Broglie (1924). On the Theory of Quanta. - https://ve42.co/theoryquanta
Larry Sorensen (2012). Path Integrals 1. University of Washington - https://ve42.co/pathintegrals
Feynman’s Method of “A Particle Exploring All Possible Paths”. (Mar 2018) via Pure Dhamma - https://ve42.co/allposspaths
A great intuitive video on the Feynman path integral approach - https://www.youtube.com/watch?v=Sp5SvdDh2u8&t=1253s
Origins of Quantum Theory. via University of Pittsburgh - https://ve42.co/origquanttheor

Images & Video:
Nobistor Altona 1880 via NDR - https://ve42.co/streetlight
Edison incandescent lights by William J. Hammer via Wikimedia Commons - https://ve42.co/edinclights
The full expanded form of the Standard Model Lagrangian by Chen Ning Yang et al. via Wikipedia - https://ve42.co/stmodellang
Muon Ray. (2011). https://www.youtube.com/watch?v=-QUj2ZRUa7c
Muon Ray. (2011). https://www.youtube.com/watch?v=1C7abO7LtV0
Bohrs Atomic Model via EEEGUIDE.COM - https://ve42.co/bohrmodel

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Special thanks to our Patreon supporters:
Adam Foreman, Albert Wenger, Alex Porter, Alexander Tamas, Anton Ragin, Autodidactic Studios, Balkrishna Heroor, Bertrand Serlet, Blake Byers, Bruce, Dave Kircher, David Johnston, David Tseng, Evgeny Skvortsov, Garrett Mueller, Gnare, gpoly, Greg Scopel, Juan Benet, Keith England, KeyWestr, Kyi, Lee Redden, Marinus Kuivenhoven, Matthias Wrobel, Meekay, meg noah, Michael Krugman, Orlando Bassotto, Paul Peijzel, qiaohui wei, Richard Sundvall, Sam Lutfi, Tj Steyn, TTST, Ubiquity Ventures, wolfee

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Directed by Casper Mebius
Written by Casper Mebius and Derek Muller
Edited by Trenton Oliver and Peter Nelson
Animated by Fabio Albertelli, Mike Radjabov, Ivy Tello, Andrew Neet and Emma Wright
Illustrations by Jakub Misiek, Tommy A. Steven and Cainejan Esperanza
Filmed by Derek Muller and Casper Mebius
Produced by Casper Mebius, Derek Muller, Rob Beasley Spence, Gabe Strong, Geeta Thakur, Emilia Gyles, Zoe Heron, Emily Zhang and Tori Brittain

Thumbnail contributions by Ignat Berbeci, Ben Powell, Jakub Misiek, Ren Hurley, and Peter Sheppard

Additional video/photos supplied by Getty Images and Storyblocks
Music from Epidemic Sound

Want my books for free? Go here: https://www.acquisition.com/audiobooks
The easiest business I can help you start (free trial): https://www.skool.com/games

If you’re new to my channel, my name is Alex Hormozi. I’m the founder and managing partner of Acquisition.com. It’s a family office, which is just a formal way of saying we invest our own money into companies. Our 10 portfolio companies bring in over $250,000,000+ per year. Our ownership stake varies between 20% and 100% of them. Given this is a YT channel, and anyone can claim anything, I’ll give you some stuff you can google to verify below.

How I got here…

21: Graduated Vanderbilt in 3 years Magna Cum Laude, and took a fancy consulting job.
23 yrs old: Left my fancy consulting job to start a business (a gym).
24 yrs old: Opened 5 gym locations.
26 yrs old: Closed down 6th gym. Lost everything.
26 yrs old: Got back to launching gyms (launched 33). Then, lost everything for a 2nd time.
26 yrs old: In desperation, started licensing model as a hail mary. It worked.
27 yrs old: "Gym Launch" does $3M profit the next 6 months. Then $17M profit next 12 months.
28 yrs old: Started Prestige Labs. $20M the first year.
29 yrs old: Launched ALAN, a software company for agencies to work leads for customers. Scaled to $1.7mmo within 6 months.
31 yrs old: Sold 75% of UseAlan to a strategic buyer in an all stock deal.
31 yrs old: Sold 66% of Gym Launch & Prestige Labs at $46.2M valuation in all-cash deal to American Pacific Group. (you can google it)
31 yrs old: Started our family office Acquisition.com. We invest and scale companies using the $42M in distributions we had taken + the cash from the $46.2M exit.
32 yrs old: Started making free content showing how we grow companies to make real business education accessible to everyone (and) to attract business owners to invest or scale their businesses.
34 yrs old: I became co-owner of https://Skool.com to help the many people who want to start a business online do so.

Today: Our portfolio now does $200M/yr between 10 companies. The largest doing $100M/yr the smallest doing $5M per year. Our ownership varies between 20% and 100% ownership of the companies. Many of them we invested in early and helped grow (which is how we make our money - not youtube videos).

To all the gladiators in the arena, we’re all in the middle of writing our own stories. The worse the monsters, the more epic the story.

You either get an epic outcome or an epic story. Both mean you win.

Keep crushing. May your desires be greater than your obstacles.

Never quit,

Alex

DISCLOSURE
Information shared here is for educational purposes only. Individuals and business owners should evaluate their own business strategies, and identify any potential risks. The information shared here is not a guarantee of success. Your results may vary.
Copyright © 2025.

WTF is a Deep Fake?

Ready or not, deep fakes are here to stay. Deep fakes are going to change the way we trust information around us and even each other. The question is - are we prepared for the threat they cause while being able to harness their potential for good?

My next video is live on Nebula NOW! It's about how countries are starting to challenge the US-led world order that emerged after World War 2. Watch now: https://nebula.tv/videos/johnn....yharris-were-heading

Check out all my sources for this video here: https://docs.google.com/docume....nt/d/1m-P_PVIa4PRfIc

-- VIDEO CHAPTERS --
0:00 Intro
1:51 Incogni
3:54 What Are Deep Fakes?
8:01 The Good Side of Deep Fakes
8:58 And the Bad Side
11:37 Misinformation
13:17 The Legal System
14:58 Cyber Crime
16:55 Solutions
18:51 Conclusion



Get access to behind-the-scenes vlogs, my scripts, and extended interviews over at https://www.patreon.com/johnnyharris

I made a poster about maps - check it out: https://store.dftba.com/produc....ts/all-maps-are-wron

Custom Presets & LUTs [what we use]: https://store.dftba.com/produc....ts/johnny-iz-luts-an

The music for this video, created by our in house composer Tom Fox, is available on our music channel, The Music Room! Follow the link to hear this soundtrack and many more: https://youtu.be/Y_WBGC_28z4

About:
Johnny Harris is an Emmy-winning independent journalist and contributor to the New York Times. Based in Washington, DC, Harris reports on interesting trends and stories domestically and around the globe, publishing to his audience of over 3.5 million on Youtube. Harris produced and hosted the twice Emmy-nominated series Borders for Vox Media. His visual style blends motion graphics with cinematic videography to create content that explains complex issues in relatable ways.

- press -
NYTimes: https://www.nytimes.com/2021/1....1/09/opinion/democra
NYTimes: https://www.nytimes.com/video/....opinion/100000007358
Vox Borders: https://www.youtube.com/watch?v=hLrFyjGZ9NU
NPR Planet Money: https://www.npr.org/transcripts/1072164745


- how i make my videos -
Tom Fox makes my music, work with him here: https://tfbeats.com/
I make maps using this AE Plugin: https://aescripts.com/geolayers/?aff=77
All the gear I use: https://www.izharris.com/gear-guide

Want to support my work? You can sign up for a paid subscription to my newsletter and YouTube channel here - https://www.distilled.earth/In this video we cover enhanced geothermal and the role it could play in decarbonizing the world's electric grid.Recently there have been a series of breakthroughs in enhanced geothermal systems, an advanced method of generating electricity from the Earth’s heat. If these developments continue, geothermal could generate between 10 and 20 percent of the country’s electricity in the coming decades, according to recent studies from the Department of Energy and Princeton.Enhanced geothermal could also solve one of clean energy’s biggest problems: intermittency. Unlike solar and wind, geothermal power plants can operate at all hours of the day, no matter the weather or time of year. In this story, I’ll cover the past, present, and future of enhanced geothermal and look at what needs to happen in order for the technology to play a large role in decarbonizing America’s power sector.All sources can be found in my article on the same topic here: https://www.distilled.earth/p/....the-new-clean-energy #technology #sustainability #geothermal #energy

The Real Reason We Drink Cow’s Milk
Click my CoPilot link https://go.mycopilot.com/johnnyharris to get a FREE TRIAL with your own expert fitness and health coach.

Ever wonder why your mom made you drink so much milk as a kid? Turns out the answer is a lie.

Btw we recently experimented with a new map only format to tell the story of the US government meddling in other countries. Check it out and let me know if you like it and we’ll do more! https://youtu.be/_wIOqHSsV9c

Next week’s video is already live. It’s about why unemployment is a much bigger deal than we realize. Go watch now on Nebula (a portion of your subscription goes directly to support our channel): https://nebula.tv/videos/johnn....yharris-unemployment

Check out all my sources for this video here: https://docs.google.com/docume....nt/d/1UbxQ_gXyq4jQRm

Get access to behind-the-scenes vlogs, my scripts, and extended interviews over at https://www.patreon.com/johnnyharris

Custom Presets & LUTs [what we use]: https://store.dftba.com/produc....ts/johnny-iz-luts-an

Thank you to Michael Moss for lending his expertise. You can read his book “Hooked” here - https://www.mossbooks.us/#HOOOKEDOutSoon

A big thank you to Melanie Dupuis for speaking to us for this video. She has a fantastic book that we cited throughout this piece. Read “Nature’s Perfect Food: How Milk Became America’s Drink” here - https://books.google.ch/books?id=V_CuITfG-FgC&pg=PA47&dq=how+we+started+drinking+milk&lr=&hl=de&source=gbs_toc_r&cad=2#v=onepage&q&f=false

Thank you to Ariana Gerstein and her film “Milk in the Land.” Check out her website to see more of her work - https://www.arianagerstein.com/

About:
Johnny Harris is an Emmy-winning independent journalist and contributor to the New York Times. Based in Washington, DC, Harris reports on interesting trends and stories domestically and around the globe, publishing to his audience of over 3.5 million on Youtube. Harris produced and hosted the twice Emmy-nominated series Borders for Vox Media. His visual style blends motion graphics with cinematic videography to create content that explains complex issues in relatable ways.

- press -
NYTimes: https://www.nytimes.com/2021/1....1/09/opinion/democra
NYTimes: https://www.nytimes.com/video/....opinion/100000007358
Vox Borders: https://www.youtube.com/watch?v=hLrFyjGZ9NU
NPR Planet Money: https://www.npr.org/transcripts/1072164745


- where to find me -
Instagram: https://www.instagram.com/johnny.harris/
Tiktok: https://www.tiktok.com/@johnny.harris
Facebook: https://www.facebook.com/JohnnyHarrisVox
Iz's (my wife’s) channel: https://www.youtube.com/iz-harris

- how i make my videos -
Tom Fox makes my music, work with him here: https://tfbeats.com/
I make maps using this AE Plugin: https://aescripts.com/geolayers/?aff=77
All the gear I use: https://www.izharris.com/gear-guide

- my courses -
Learn a language: https://brighttrip.com/course/language/
Visual storytelling: https://www.brighttrip.com/cou....rses/visual-storytel

Are Vitamins and Supplements a Scam?
Click https://go.mycopilot.com/johnny-harris to get 14 days FREE with your own personal trainer!

The supplements industry — with all its vitamins, weight loss pills, workout powders, and hormones — has been growing exponentially over the last couple of decades despite there being no increased regulations for them. We wanted to know — are supplements dangerous to take, and are they even effective?

Thank you to the experts we spoke with that helped with our research in this story:
Dr. C. Michael White, Pharm.D., FCP, FCCP
Dr. F. Perry Wilson, MD, MSCE
Dr. Edzard Ernst, MD, PhD, MAE, FMedSci, FRSB, FRCP

And thank you to Ryan Howkins, the founder of the Lion’s Mane Recovery subreddit, who brought the Lion’s Mane story to our team. You can find the subreddit here: http://reddit.com/r/LionsManeRecovery

Resources to look up supplements and vitamins:
US Pharmacopeia: https://www.usp.org/
NSF: https://www.nsf.org/

My next video is live on Nebula NOW! It's about how the world economy is changing. Watch now: https://nebula.tv/videos/johnn....yharris-how-the-worl

Check out all my sources for this video here: https://docs.google.com/docume....nt/d/1QpeAf2LG20Hzlo

-- VIDEO CHAPTERS --
0:00 Intro
3:57 How the Supplement Industry Works
12:25 What the Science Says
17:34 Supplements Gone Bad
25:19 What Can Be Done
28:28 Announcements & Outro

Check out my new channel with Sam Ellis - Search Party: https://youtube.com/@Search-Party

Get access to behind-the-scenes vlogs, my scripts, and extended interviews over at https://www.patreon.com/johnnyharris

Do you have an insider tip or unique information on a story? Do you have a suggestion for a story you want us to cover? Submit to the Tip Line: https://docs.google.com/forms/....d/e/1FAIpQLSdpNs1ykI

I made a poster about maps - check it out: https://store.dftba.com/produc....ts/all-maps-are-wron

Custom Presets & LUTs [what we use]: https://store.dftba.com/produc....ts/johnny-iz-luts-an

The music for this video, created by our in house composer Tom Fox, is available on our music channel, The Music Room! Follow the link to hear this soundtrack and many more: https://www.youtube.com/watch?v=5hDeO03FIZ4

About:
Johnny Harris is an Emmy-winning independent journalist and contributor to the New York Times. Based in Washington, DC, Harris reports on interesting trends and stories domestically and around the globe, publishing to his audience of over 3.5 million on Youtube. Harris produced and hosted the twice Emmy-nominated series Borders for Vox Media. His visual style blends motion graphics with cinematic videography to create content that explains complex issues in relatable ways.

- press -
NYTimes: https://www.nytimes.com/2021/1....1/09/opinion/democra
NYTimes: https://www.nytimes.com/video/....opinion/100000007358
Vox Borders: https://www.youtube.com/watch?v=hLrFyjGZ9NU
NPR Planet Money: https://www.npr.org/transcripts/1072164745


- where to find me -
Instagram: https://www.instagram.com/johnny.harris/
Tiktok: https://www.tiktok.com/@johnny.harris
Facebook: https://www.facebook.com/JohnnyHarrisVox
Iz's (my wife’s) channel: https://www.youtube.com/iz-harris

- how i make my videos -
Tom Fox makes my music, work with him here: https://tfbeats.com/
I make maps using this AE Plugin: https://aescripts.com/geolayers/?aff=77
All the gear I use: https://www.izharris.com/gear-guide

- my courses -
Learn a language: https://brighttrip.com/course/language/
Visual storytelling: https://www.brighttrip.com/cou....rses/visual-storytel

A ton of your devices use Bluetooth to communicate wirelessly. But how does Bluetooth work? In this video, we'll dive into the details of how your smartphone sends audio to your wireless headphones. Bluetooth is rather complicated and thus we're going to use a number of analogies and tools to explain it fully.

This video is sponsored by KIOXIA. Visit KIOXIA's website to see their lineup of solid-state drives:
www.kioxia.com

Do you want to support in-depth engineering and technology education? Support us on: https://www.patreon.com/brancheducation

Website: https://www.branch.education
On Facebook: https://www.facebook.com/BranchEducation/
On Twitter: https://twitter.com/TeddyTablante
On Insta: https://www.instagram.com/brancheducation/

Or Join us on YouTube Memberships: https://www.youtube.com/channe....l/UCdp4_l1vPmpN-gDbU

This video is part of a series that explores how wireless headphones work.
1) Audio Codecs https://youtu.be/_ZKNOKHpqE4
2) Noise Cancellation https://youtu.be/VIi04uD8LtY

Script, Modelling, Animation, Editing- Teddy Tablante
Twitter: @teddytablante
Voice Over- Phil Lee

Table of Contents:
00:00 - How does Bluetooth Work?
00:37 - Traffic Lights
01:26 - 2.4GHz Spectrum
02:44 - Issues with the Bluetooth Visualization
05:56 - Details behind Bluetooth
07:30 - Bluetooth Packets
08:27 - Frequency Hopping Spread Spectrum
10:58 - Noise in the 2.4GHz Spectrum
13:05 - Bluetooth Signal Integrity
14:21 - Sponsored Segment
15:33 - Frequency Shift Keying & Phase Shift Keying
18:16 - More Details on Scheduling & Packets
20:43 - Outro

Key Branches from this video are: Wireless Headphones & Audio Codecs, Noise Cancellation

Erratum:

Animation built using Blender 2.90.1 https://www.blender.org/
Post with Adobe Premiere Pro

Additional Patreon / YouTube Member Credits Not Shown in the Video:
Adit Kaul

Credits:
Wikipedia contributors. "Bluetooth", "Frequency-Shift Keying" , "Phase-Shift Keying" , "Wireless" Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia, Visited May, 2021

Music Credits
Sunburst, Tobu & Itro is licensed under Creative Commons Attribution License
http://www.7obu.com
https://www.youtube.com/watch?v=4lXBHD5C8do

#bluetooth #wireless #headphones