Earlier quoted context omitted.
forgot: here's the paper (it's just mentioned in Japanese in the video) https://journals.asm.org/doi/10.1128/mSphere.00637-20 your controlled experiment with Sars-COV-2 particles :)
from the paper (emphasis mine): > Here, we developed an airborne transmission SIMULATOR of infectious SARS-CoV-2-containing droplets/aerosols produced by human respiration and coughs and assessed the transmissibility of the infectious droplets/aerosols and the ability of various types of face masks to block the transmission. Mannequin heads in a box is perhaps evidence of something , but it has little to do with actu…
Also they just tested one mask.
In HK, Taiwan and Japan a lot of people are wearing 2 masks:
1 surgical mask and a cotton mask on top :)
Doesn't help at all (check Taiwan's and HK's numbers compared with Texas ... much higher population density).