At 50% ambient relative humidity and half a second after a cough, droplets 0.01 mm in diameter (blue) remain afloat in turbulent eddies while ones that are 10 times (green) or 100 times (red) larger fall away.

From the article:

Extended Lifetime of Respiratory Droplets in a Turbulent Vapor Puff and Its Implications on Airborne Disease Transmission
Kai Leong Chong, Chong Shen Ng, Naoki Hori, Rui Yang, Roberto Verzicco, and Detlef Lohse
Phys. Rev. Lett. 126, 034502 (2021)

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