There is no doubt that we should wear face masks during the pandemic. While they may not fully protect you from contracting the virus, they can be of immense help for not spreading it further. LaVision decided to show you how it all works. They used an over 150-year-old photographic technique to make a short, but very illustrative video that shows how masks help during the pandemic.
“The primary way of person-to-person coronavirus transmission is via aerosols or small droplets created by breathing, sneezing or coughing,” LaVision explains. This is why CDC’s official recommendation is to wear a mask when going outside, to a grocery store etc.
In the video above, LaVision used the Schlieren imaging technique to visualize the airflow caused by a person breathing and coughing. A person without the mask is compared to the person with the mask as they breathe and cough. The difference is pretty obvious, and the video shows just how much a mask restricts the movement of air as we breathe or cough.
To create this video, LaVision used Background Oriented Schlieren or BOS imaging. It’s a “simple and cost-effective alternative to laser imaging methods, because it doesn’t need any complex illumination device like a laser needed for laser imaging, and it works without seeding the flow,” LaVision writes. Interestingly enough, the technique was invented back in 1864. German physicist August Toepler invented it to study supersonic motion, and it’s used to this day in aeronautical engineering to photograph the flow of air around objects. You can read more about the technique here and here.
Some YouTube comments read that it would be great to make a video that compares a surgical mask and a makeshift cloth mask. Considering that we’re in a serious lack of surgical masks here in Serbia (and doctors certainly need them more), I’d also like to see how these two types of masks differ.