They may- in a fit of panic. More common to see them clutch at their throat.
A clock has hands but cannot wave.
When you clap your hands together, you create a compression wave, also known as a sound wave. This wave is produced by the vibrations of your hands colliding and propagates through the air as a pressure disturbance that we perceive as sound.
The universal sign is someone who has their hands at their throats. Other signs are an inability to breath or make sounds because the windpipe is blocked off. Or there may be some wheezing sounds because the windpipe is partially blocked.
A clock
When you clap your hands together, the rapid collision of your hands creates a compression wave in the air. This compression wave travels to your ears and is picked up by your eardrums, which vibrate in response to the sound wave, sending signals to your brain that are interpreted as the sound of a clap.
mechanical wave
wave your hands and say pick me up
Press W when not typing.
the hands make a compression wave that travels through the air. Your ears pick up that compression wave and turns it into a neuron impulse that your brain registers as sound.
When a wave bends around an obstacle, it is called diffraction.
someone.
People wave to visually say hi or bye to each other from a far distance. People also use waving to get someone's attention. It has been around for so long that people just do it.