From: veritasium
The Magnus effect is a phenomenon that influences the flight of rotating objects moving through a fluid, such as air [00:00:52]. It is observed when a ball or cylinder spins, causing air on one side to move in the same direction as the spin, and air on the opposite side to move against it [00:00:59]. This interaction creates a net force on the object, pushing it in the direction of the air deflected by the spin [00:01:14].
The effect was described by Heinrich Gustav Magnus in 1852 [00:01:22], though Isaac Newton had observed it nearly two centuries earlier in the flight of tennis balls [00:01:27].
Demonstration at Gordon Dam
Friends dropped a basketball from the Gordon Dam in Tasmania, which is 126.5 meters (415 feet) high [00:00:02] [00:00:05].
- A basketball dropped without spin landed directly below the drop point, only slightly pushed by the breeze [00:00:18].
- When a basketball was dropped with backspin, it dramatically took off horizontally, moving far from its initial drop point [00:00:24] [00:00:43]. This dramatic deviation was due to the Magnus effect [00:00:50].
Sports Applications
The Magnus effect is highly significant in various sports involving projectile motion:
- Tennis [00:01:36]
- Soccer [00:01:36]
- Golf [00:01:36]
Non-Sport Applications
While crucial in sports, the Magnus effect also has potential non-sport applications:
Flettner Rotors on Ships
Ships can be propelled using spinning cylinders called “Flettner rotors” instead of traditional sails [00:01:49] [00:01:52]. These rotors deflect crosswinds, using the Magnus effect to propel the ship forward [00:01:55]. An example is the E-Ship 1, which uses four Flettner rotors to increase efficiency and reduce diesel consumption [00:02:25] [00:02:30].
Experimental Aircraft
The Magnus effect has been explored in aircraft design:
- An experimental plane was designed with spinning cylinders taking the place of wings [00:02:00].
- These cylinders generated more lift than traditional wings using the Magnus effect [00:02:04].
- However, they also created significantly more drag, making the design impractical; this particular plane only flew once before crashing [00:02:09] [00:02:13].
- Despite past setbacks, the Magnus effect is seeing a comeback, with experimental rotor wing aircraft designed to generate all their lift from spinning cylinders [00:02:17] [00:02:19].
The future may see the Magnus effect assisting more than just basketballs in flight [00:02:35].