A very good illustration.
Experiments with dummy heads and masks. Credit: TU Wien
Tiny droplets loaded with viruses disappear more slowly after exhalation than previous models suggested. Experiments and simulations by TU Wien (Vienna) can now explain this.
It is easier to get infected in winter than in summer — this is true for the Corona pandemic, for influenza, and for other viral diseases. Relative humidity plays an important role in this. Outdoors, it is much higher outside in winter than in summer, as can be seen from the fact that our breath condenses into droplets in the cold air.