Backspin Basketball Flies Off Dam
Why Hacker News recommends it
HN uses it as a quick, clear demonstration of the Magnus effect behind spinning-cylinder ships and planes.
What it is
A short Veritasium video showing how far a backspinning basketball would travel dropped off a dam. It demonstrates the Magnus effect and links to Flettner rotor ships and aircraft.
Recommended by 3 HN commenters across 3 different months, 2015 to 2021.
What Hacker News said
Recommends sndean · 2016-11 · on “Bouncing bomb”
There's a decent video by Veritasium about the Magnus Effect, where the bomb is essentially given lift by its backspin: [this video]
Recommends pqdbr · 2020-12 · on “Rotating Sails Help to Revive Wind-Powered Shipping”
There's a great Veritasium video explaining the Magnus effect and the Flettner rotor here: [this video] The Norsepower company (which installs Flettner rotors on ships) also has a short video explaining the effect here [LINK]
Recommends krisoft · 2021-05 · on “How to design a sailing ship for the 21st century?”
I'm not an expert on it really. They rotate the giant cylinder and the wind is blowing by. The rotation forms a low pressure zone one side of the cylinder which acts as a lift force perpendicular both to the rotational axis of the cylinder and the wind. It's the same effect which "turns" a soccer ball if you kick it with a spin. There is a really nice demonstration of the effect in this video: [this video] This wikipedia page has a way better summary than my attempt above: [LINK]
Cites tfigment · 2015-07 · on “What is the most ridiculous aircraft design?”
My favorite is the Flettner aeroplane since it uses the Magnus effect [1][2] as it generates lift without a wing. Screenshot linked in the original post [3]. [1] [LINK] [2] [this video] [3] [LINK]
Cites cgag · 2018-10 · on “Wind-powered ships are making a comeback”
This is the video they reference at the end that elaborates and shows off the use in ships, as well as some planes that have spinning cylinders instead of wings: [this video]