Anatomy of a Sneeze
You know to cover up when you sneeze. That’s just good etiquette.
But you might be surprised by the findings of a study published in Experiments in Fluids (yes, that’s a real journal) that shines a light on how the germs you’re unleashing on the world explode from your body.
Researchers discovered that when a person sneezes, the fluid is not dispersed in a uniform mist, as you might imagine. Instead, they found that a "balloon" of fluid emerges from the mouth. This balloon then breaks down into long threads before dispersing as a spray of droplets. They compare the process to "paint that is flung through the air."
The team used two high-speed monochrome cameras to record more than 100 sneezes of three healthy participants who were placed against a black backdrop. The high-speed imaging allowed researchers to capture around 200 milliseconds of each participant's sneezes and analyze them frame by frame. (Follow the link below to see a cool picture of a sneeze forming.)
Investigators noted that as soon as fluid leaves a person's mouth through sneezing, it combines with the simultaneously exhaled air to form a balloon. As this balloon moves through the air, it breaks into thin threads that divide into sprays of different-sized droplets, which either stay in the air or fall to the ground.
The findings were surprising, since the team expected to see droplets coming out fully formed from the respiratory tract. This new information could prove to be an important step in understanding the mechanics of what is termed “violent expirations," and help identify individuals who are most likely to spread illness.