Engineering Feed

The Space Telescope That Will Reveal the Universe’s Biggest Secret

Click this link https://boot.dev/?promo=REALENGINEER and use my code REALENGINEER to get 25% off your first payment for boot.dev Watch this video ad free on Nebula: https://nebula.tv/videos/realengineering-the-insane-engineering-of-the-nancy-grace-roman-telescope Links to everything I do: https://beacons.ai/brianmcmanus Get your Real Engineering shirts at: https://standard.tv/collections/real-engineering Credits: Producer/Writer/Narrator: Brian McManus Head of Production: Mike Ridolfi Editor: Dylan Hennessy Writer/Research: Josi Gold Animator: Eli Prenten Animator: Stijn Orlans Sound and Production Coordinator: Graham Haerther Sound: Donovan Bullen Thumbnail: Simon Buckmaster Head of Moral: Shia LeWoof Select imagery/video supplied by Getty Images Thank you to my patreon supporters: Oliver Olsen Gerard Maggiolino Hayley Ben Jay Maglione Vern Knowles Fergus Lynch Eric Lyness Claire Han C. Tran Casper Kroon Sasha Reid Nathan Baum Javier Soto Ciarán Eric S. John Monsees John C Monsees Jonathan Mayhew Grant Grossbier Alfred Holzheu

How We Could Reach Proxima Centauri B in 20 Years

Help us continue to turn down crappy sponsors: https://www.patreon.com/c/realengineering Thank you to my patreon supporters: Eric Lyness Claire Han C. Tran Casper Kroon Sasha Reid Javier Soto Ciarán Eric S. John Monsees John C Monsees Jonathan Mayhew Grant Grossbier Alfred Holzheu

Are Beavers Actually Good at Dams?

Want to restore the planet’s ecosystems and see your impact in monthly videos? The first 100 people to join Planet Wild with my code PRACTICAL8 will get the first month paid for by me: https://planetwild.com/r/practicalengineering/join/8 If you want to get to know them better first, check out their wildlife crossings mission: https://planetwild.com/r/practicalengineering/m36/8 Do the beavers have a better dam system? 📖My new book, Disasters By Design: How Engineering Failures Shaped the Modern World is coming March 2, 2027 and available for preorder now. US: https://www.penguinrandomhouse.com/books/786143/disasters-by-design-by-grady-hillhouse/ UK: https://www.penguin.co.uk/books/476190/disasters-by-design-by-hillhouse-grady/9780241798508 More About the Book: https://practical.engineering/books Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-are-beavers-actually-good-at-dams Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by Planet Wild. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios Thanks to Ian Slater for sharing some beaver footage (https://www.youtube.com/@porchlandia) MUSIC CREDITS ____________________________________ Recycled Mood from Epidemic Sound Tapped Out from Epidemic Sound Water and Light composed by Caleb Winters (https://beacons.ai/calebwinters) Edge of a Knife composed by Caleb Winters Woodland Expedition composed by Caleb Winters

I made an apple peel itself

Go to https://brilliant.org/StuffMadeHere/ try the tutor for free and get 20% off your annual premium subscription! SAFETY NOTICE This video depicts an experimental system involving high-pressure steam. Boilers and pressure vessels contain substantial stored energy and can cause severe injury or death if they fail or are operated improperly. Their construction and use may also be governed by engineering codes, inspection requirements, permits, and other regulations that vary by jurisdiction and application. This video is a record of an experiment, not a construction guide. Do not copy, reproduce, or operate equipment based on what is shown here. A hydrostatic test, a pressure relief valve, or an engineering background does not by itself make a homemade pressure system safe. Anyone working with pressurized steam should consult qualified pressure-equipment professionals and the applicable authorities before building or operating anything similar. SOURCES: Belleville washers: https://en.wikipedia.org/wiki/Belleville_washer

The Grid That Doubles the Strength of the Ground

I love geocells ⚙️ Check out SendCutSend for custom parts fabricated from your CAD: http://sendcutsend.com/practicalengineering Sometimes it’s not all about more massive concrete slabs or the brute strength of steel, but just a little bit of clever geometry and some dirt. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-the-grid-that-doubles-the-strength-of-the-ground Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by SendCutSend. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ Cactus Song from Epidemic Sound Practical Engineering Theme composed by Caleb Winters (https://beacons.ai/calebwinters) Keyless Entry from Epidemic Sound Woodland Expedition composed by Caleb Winters Water and Light composed by Caleb Winters

How a 144-Year Architectural Puzzle Was Solved

Get Nebula for 50% off with my link: https://go.nebula.tv/realengineering Watch this video on Nebula: https://nebula.tv/videos/realengineering-why-sagrada-familia-took-144-years-to-finish The bonus Nebula video: https://nebula.tv/videos/realengineering-how-the-stained-glass-of-sagrada-familia-was-designed Links to everything I do: https://beacons.ai/brianmcmanus Get your Real Engineering shirts at: https://standard.tv/collections/real-engineering Credits: Producer/Writer/Narrator: Brian McManus Head of Production: Mike Ridolfi Editor: Dylan Hennessy Writer/Research: Josi Gold Animator: Eli Prenten Animator: Stijn Orlans Sound and Production Coordinator: Graham Haerther Sound: Donovan Bullen Thumbnail: Simon Buckmaster Head of Moral: Shia LeWoof References: Select imagery/video supplied by Getty Images Thank you to AP Archive for access to their archival footage. Music by Epidemic Sound: http://epidemicsound.com/creator Thank you to my patreon supporters: Abdullah Alotaibi, Adam Flohr, Henning Basma, Hank Green, William Leu, Tristan Edwards, Ian Dundore, John & Becki Johnston. Nevin Spoljaric, Jason Clark, Thomas Barth, Johnny MacDonald, Stephen Foland, Alfred Holzheu, Abdulrahman Abdulaziz Binghaith, Brent Higgins, Dexter Appleberry, Alex Pavek, Marko Hirsch, Mikkel Johansen, Hibiyi Mori. Viktor Józsa, Ron Hochsprung

What's Under Your Feet in New York City?

A tour of the subsurface in NYC ⚙️ Check out SendCutSend for custom parts fabricated from your CAD: http://sendcutsend.com/practicalengineering The underground of New York is almost a city within a city. We kind of get used to having all these utilities and services that it’s easy to forget the physical space they all take up and the work that goes into installing and maintaining them. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-whats-under-your-feet-in-new-york-city Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by SendCutSend. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ Himalayan Spell from Epidemic Sound Keyless Entry from Epidemic Sound Water and Light composed by Caleb Winters (https://beacons.ai/calebwinters) Tapped Out from Epidemic Sound Woodland Expedition composed by Caleb Winters (https://beacons.ai/calebwinters)

Why the Nokia 3310 was so Durable

The Insane Engineering of the V-22 Osprey

Get Nebula for 50% off with my link: https://go.nebula.tv/realengineering Watch this video ad free on Nebula: https://nebula.tv/videos/realengineering-the-insane-engineering-of-the-v22-osprey Links to everything I do: https://beacons.ai/brianmcmanus Get your Real Engineering shirts at: https://standard.tv/collections/real-engineering Credits: Producer/Writer/Narrator: Brian McManus Head of Production: Mike Ridolfi Editor: Dylan Hennessy Writer/Research: Josi Gold Animator: Eli Prenten Animator: Stijn Orlans Sound and Production Coordinator: Graham Haerther Sound: Donovan Bullen Thumbnail: Simon Buckmaster Head of Moral: Shia LeWoof References: Select imagery/video supplied by Getty Images Thank you to AP Archive for access to their archival footage. Music by Epidemic Sound: http://epidemicsound.com/creator Thank you to my patreon supporters: Abdullah Alotaibi, Adam Flohr, Henning Basma, Hank Green, William Leu, Tristan Edwards, Ian Dundore, John & Becki Johnston. Nevin Spoljaric, Jason Clark, Thomas Barth, Johnny MacDonald, Stephen Foland, Alfred Holzheu, Abdulrahman Abdulaziz Binghaith, Brent Higgins, Dexter Appleberry, Alex Pavek, Marko Hirsch, Mikkel Johansen, Hibiyi Mori. Viktor Józsa, Ron Hochsprung

The Wild Story of the Teton Dam Failure

This year is the 50th anniversary of the Teton Dam Failure 🌌Get Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/practical-engineering 🚣Watch Joe Scott - Oldest and Newest Places on Earth: https://nebula.tv/oldestnewest?ref=practical-engineering Teton was one of the most dramatic and catalyzing dam failures of the 20th century in the US. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-the-wild-story-of-the-teton-dam-failure Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by Nebula. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ Building Blocks from Epidemic Sound Aural Imprints from Epidemic Sound Addicted To Me from Epidemic Sound Magnified XY from Epidemic Sound The Road Less Travelled from Epidemic Sound

Engineering a $1 Cup of Lemonade #AdobePartner

No denying the video turned out better than the lemonade. @Adobe

Robot golf vs holes that keep getting harder

Check out https://brilliant.org/StuffMadeHere/ for a free 30-day trial and 20% off your annual premium subscription! See how I designed and made the club: https://youtu.be/JQB8aNKyeao I decided to spend months giving my robotic club a massive software upgrade so that it can understand physics and solve challenging mini golf holes. Sources: Ackley function vis: https://en.wikipedia.org/wiki/Differential_evolution#/media/File:Ackley.gif 3D Scanner video: https://www.revopoint3d.com/products/trackit-optical-tracking-3d-scanner

Some Spillways Fail on Purpose

An overview of fuse plug and fusible gate spillways ⚙️ Check out SendCutSend for custom parts fabricated from your CAD: http://sendcutsend.com/practicalengineering Most of the largest dams in the world have gated spillways with whole teams of staff dedicated to their operation. But it’s still a challenge, especially for small owners like cities. So there is another option, kind of in between controlled and uncontrolled spillways, and its use is growing worldwide. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-spillways-that-fail-on-purpose Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by SendCutSend. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ Addicted To Me from Epidemic Sound Practical Engineering Theme composed by Caleb Winters (https://beacons.ai/calebwinters) Tapped Out from Epidemic Sound Water and Light composed by Caleb Winters (https://beacons.ai/calebwinters) Building Blocks from Epidemic Sound

How American Tanks are being Destroyed in Ukraine

Tank Engines are Weird

The Nuclear Reactor Hidden Under Greenland

Get Nebula for 50% off with my link: https://go.nebula.tv/realengineering Watch this video ad free on Nebula: https://nebula.tv/videos/realengineering-the-illegal-nuclear-reactor-built-under-greenland Links to everything I do: https://beacons.ai/brianmcmanus Get your Real Engineering shirts at: https://standard.tv/collections/real-engineering Credits: Producer/Writer/Narrator: Brian McManus Writers: Malik Klalib and Brian McManus Head of Production: Mike Ridolfi Senior Editor: Dylan Hennessy Sound Design: Donovan Bullen Animators: Mike Ridolfi & Ratimir Rakuljic Select imagery/video supplied by Getty Images Thank you to my patreon supporters: Abdullah Alotaibi, Adam Flohr, Henning Basma, Hank Green, William Leu, Tristan Edwards, Ian Dundore, John & Becki Johnston. Nevin Spoljaric, Jason Clark, Thomas Barth, Johnny MacDonald, Stephen Foland, Alfred Holzheu, Abdulrahman Abdulaziz Binghaith, Brent Higgins, Dexter Appleberry, Alex Pavek, Marko Hirsch, Mikkel Johansen, Hibiyi Mori. Viktor Józsa, Ron Hochsprung

The Los Angeles Aqueduct is Wild

A little tour of the Los Angeles Aqueduct system 🌌Get Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/Practical-Engineering 🚣Watch The Colorado Problem: https://nebula.tv/thecoloradoproblem?ref=practical-engineering The story of the LA aqueduct in a nutshell: The project seemed obvious from an engineering perspective. But it many ways, it was not only unscrupulous, but also short-sighted. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-the-los-angeles-aqueduct-is-wild Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by Nebula. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ Recycled Mood from Epidemic Sound Cave Thoughts composed by Donovan Bullen (Nebula Studios) Magnified XY from Epidemic Sound Building Blocks from Epidemic Sound All Parts Equal from Epidemic Sound

The SECRET to Fighting Laundry Stains #TidePartner

The SECRET to Fighting Laundry Stains #TidePartner

How Liquid Dampers in Skyscrapers Work

How sloshes quash wobbles in skyscrapers. 🌌Get Nebula using my link for 40% off an annual subscription: https://go.nebula.tv/Practical-Engineering 🏙️Watch 17 Pages: https://nebula.tv/videos/17pages?ref=practical-engineering Errata: At 8:12, the One Wall Centre building is incorrectly identified. It's actually the one on the left side of the screen. Liquid dampers are the unsung heroes of structural vibration control. They take up more space, but they’re simple, cost-effective, straightforward, and pretty darn cool. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-the-hidden-engineering-of-liquid-dampers Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by Nebula. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ Cactus Song from Epidemic Sound Tonic and Energy by Elexive is licensed under a Creative Commons Attribution License (Source: https://www.youtube.com/watch?v=U6fBPdu8w9U) Cave Thoughts composed by Donovan Bullen (Nebula Studios) Rhubarb from Epidemic Sound Tapped Out from Epidemic Sound Heart Beam from Epidemic Sound

The Hidden Engineering of Floating Bridges

An engineering tour of Washington's floating concrete highways There aren’t that many permanent floating bridges around the globe, but they're full of creative solutions and unexpected stories. Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-how-floating-bridges-work Signed copies of my book (plus other cool stuff) are available here: https://store.practical.engineering/ Practical Engineering is a YouTube channel about infrastructure and the human-made world around us. It is hosted, written, and produced by Grady Hillhouse. We have new videos posted regularly, so please subscribe for updates. If you enjoyed the video, hit that ‘like’ button, give us a comment, or watch another of our videos! CONNECT WITH ME ____________________________________ Website: http://practical.engineering Twitter: https://twitter.com/HillhouseGrady Instagram: https://www.instagram.com/practicalengineering Reddit: https://www.reddit.com/r/PracticalEngineering Facebook: https://www.facebook.com/PracticalEngineerGrady​ Patreon: http://patreon.com/PracticalEngineering SPONSORSHIP INQUIRIES ____________________________________ Please email my agent at [email protected] DISCLAIMER ____________________________________ This is not engineering advice. Everything here is for informational and entertainment purposes only. Contact an engineer licensed to practice in your area if you need professional advice or services. All non-licensed clips used for fair use commentary, criticism, and educational purposes. SPECIAL THANKS ____________________________________ This video is sponsored by Ground News. Stock video and imagery provided by Getty Images, Shutterstock, Pond5, and Videoblocks. Video by Grady Hillhouse Edited by Wesley Crump Produced by Ralph Crewe Graphics by Nebula Studios MUSIC CREDITS ____________________________________ The Early Bird from Epidemic Sound Tapped Out from Epidemic Sound Cave Thoughts composed by Donovan Bullen (Nebula Studios) Pattern View from Epidemic Sound Recycled Mood from Epidemic Sound Tonic and Energy by Elexive is licensed under a Creative Commons Attribution License (Source: https://www.youtube.com/watch?v=U6fBPdu8w9U)