Eli5. Why does a baseball sizzle when thrown hard.

Question

My son plays ball and asked me this. I’m guessing it has to do with the seams.

In: 1

Answer 1

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Answer 2

You are correct to suspect the seams. The seams create a non uniform surface. When the ball is thrown at high velocity, it is most often imparted with a high spin rate (except knuckleball). The rotation of the ball causes the seams to created a regular disturbance and vibration of air molecules around the ball. We can then sense the vibrations as hearing a sizzle.

Edit: Think ground spinning fireworks.