Can Waves Really Transmit Angular Momentum?

AI Thread Summary
Waves can indeed transmit angular momentum, contrary to some beliefs. Electromagnetic waves, particularly circularly polarized light, can carry both orbital and spin angular momentum, causing objects like plates to twist when exposed to them. Similar principles apply to mechanical waves; for instance, sending circular waves down a rope connected to a rotating disc can impart angular momentum to the disc, causing it to spin. These experiments demonstrate the ability of waves to transfer angular momentum effectively. Understanding this phenomenon has implications in various fields of physics and engineering.
Himal kharel
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why can't a wave transmit angular momentum?
 
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They can and do. Electromagnetic waves can carry both orbital and spin angular momentum. If you shine a beam of circularly polarized light on a plate, the plate will twist slightly. This has been http://prola.aps.org/abstract/PR/v50/i2/p115_1" .

You could do a similar experiment with waves on a string. Connect a rope to one edge of a disc mounted so that it is free to rotate about its axis. Hold the other end and send circular waves down the rope and you will be able to get the disc spinning. The angular momentum in the wave is imparted to the disc.
 
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