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Comment by tim-fan | Hacker News Reader

>As two flat hands collide, the air between them is forced out increasingly quickly, ultimately exceeding the speed of sound. This creates an abrupt pressure change, resulting in shock waves that make up a large part of the noise we hear

So the clap is a mini sonic boom between your hands?

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The sonic boom comes from the object going faster than its own soundwave and crossing it, this just seems to be the product of a big pressure differential between the clap and ambiant air

That sounds surprising to me, too, because I can vary the loudness by moving one hand faster or slower towards the other. My intuition says that a sonic boom is a "catastrophic" event, so there should be a threshold. I'm wondering how they measured that.

The most interesting part of this statement is that you physically move both hands to clap… I let my dominant hand “hit” my other hand… is that not how everyone does it lol

I mostly move both, but vary a bit depending on intensity and frequency. It's faster to clap against, but I get more sound moving both. It also spreads the effort, so I prefer it for low intensity clapping.

I think you'll be ok, considering at least one person does this: https://twitter.com/MetroUK/status/748854767938473984

Look around sometime. I never see everybody clapping the same way. There are tons of variations, including what you do, and plenty of people use them.

I do not believe there is a literal "sonic boom" when clapping. It's possible to cap very slowly and still make a small noise and I don't believe my slow-clapping is pushing air around at 343 meters per second.

Why not? The size of the channel it has to move through goes to zero as your hands meet, but the volume reduction per second is roughly constant. That means the velocity goes to "infinity."

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