Experiments are done to gather information to help provide answers to questions. So before starting any experiment, we first need to figure out what the question is. The obvious question that might be asked is:
Does wearing a mask help prevent the spread of covid?
That's obviously what is important. However, that question is too broad to be easily answered directly. Let's back up a bit and consider how covid can be spread. The World Health Organization has a good scientific brief available here. From that article, they identify several "Modes of transmission", including:
- Contact and droplet transmission - droplets >5-10 micrometers (um) in diameter via coughing, sneezing, or even talking.
- Airborne transmission - droplets <5um in diameter.
- Fomite transmission (contaminated surfaces) - when the above sources land on a surface.
- When people with COVID-19 cough, sneeze, sing, talk, or breathe they produce respiratory droplets.
So let's focus on those "droplets" - these >5-10um diameter airborne "blobs" that come flying out of our mouths. Can a mask stop those? Well, that's something we can more easily test directly. So let's state that as our question:
Does a mask reduce the amount of droplets?
The general idea will be to create a laser light sheet into which we can speak and spew forth our blobs. The laser sheet will illuminate them and we will capture the results via video, which we can then process. Let's look at the hardware specifics in more detail.