--- title: The Physics Behind the Thumb Trick link: https://www.youtube.com/watch?v=fKuIJ_z2Y6A source: youtube-com-practicalengineeringchannel published: 2026-05-05T13:01:16Z updated: 2026-09-01T06:22:26Z first_seen: 2026-09-08T10:17:10.166315Z authors: - Practical Engineering summary: |- _Closed Conduit Hydraulics_ is a place where intuitions don’t always serve you well ⚙️ Check out SendCutSend for custom parts fabricated from your CAD: http://sendcutsend.com/practicalengineering The garden hose is a backyard version of the same problem engineers and operators deal with every day: how much flow can you get through a real system, and what does it cost you in pressure? Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-the-physics-behind-the-thumb-trick 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 practicalengineering@standard.tv 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 ____________________________________ Tapped Out from Epidemic Sound Practical Engineering Theme composed by Caleb Winters (https://beacons.ai/calebwinters) Water and Light composed by Caleb Winters Woodland Expedition composed by Caleb Winters Tonic and Energy by Elexive is licensed under a Creative Commons Attribution License Source: https://www.youtube.com/watch?v=U6fBPdu8w9U content: extracted html: 2026-05-05-the-physics-behind-the-thumb-trick.html preview: file: 2026-05-05-the-physics-behind-the-thumb-trick.preview-35053624bf5f.webp width: 256 height: 192 color: '#7d6f6c' images: - source: https://i.ytimg.com/vi/fKuIJ_z2Y6A/maxresdefault.jpg original: file: 2026-05-05-the-physics-behind-the-thumb-trick.image-935794a7644f.jpg width: 1280 height: 720 variants: - file: 2026-05-05-the-physics-behind-the-thumb-trick.image-6543db13cbeb.webp width: 48 height: 27 color: '#e9d3b6' extra: thumbnail: https://i3.ytimg.com/vi/fKuIJ_z2Y6A/hqdefault.jpg --- \_Closed Conduit Hydraulics\_ is a place where intuitions don’t always serve you well\ ⚙️ Check out SendCutSend for custom parts fabricated from your CAD: http://sendcutsend.com/practicalengineering The garden hose is a backyard version of the same problem engineers and operators deal with every day: how much flow can you get through a real system, and what does it cost you in pressure? Watch this video ad-free on Nebula: https://nebula.tv/videos/practical-engineering-the-physics-behind-the-thumb-trick 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 practicalengineering@standard.tv 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\ \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\ Tapped Out from Epidemic Sound\ Practical Engineering Theme composed by Caleb Winters (https://beacons.ai/calebwinters)\ Water and Light composed by Caleb Winters\ Woodland Expedition composed by Caleb Winters\ Tonic and Energy by Elexive is licensed under a Creative Commons Attribution License\ Source: https://www.youtube.com/watch?v=U6fBPdu8w9U