Sneezing is even more disgusting with high-speed cameras

MIT likens it to "throwing paint".

New, super-gross research out of MIT is shedding new insights into what happens when we sneeze. Researchers from the university used high-speed photography to record 100 healthy volunteers right at the moment they sneezed. Turns out, the sticky fluid flies out of our mouths, not as a spray, but as a sheet. Ew. Then it pops, like a balloon, and the snotty filaments remaining then in turn break up into the fine mist we're familiar with. Double ew.

Top and side views of the rapid fragmentation process of mucosalivary fluid occurring during a healthy sneeze. They reflect the sequence of formation of sheets and then filaments, ultimately leading to the formation of respiratory droplets outside of the mouth. These were captured with a camera operating at 6,000 to 8,000 frames per second.

This is actually really important research as it can help researchers better understand how airborne diseases spread. "It's important to understand how the process of fluid breakup, or fluid fragmentation, happens," Lydia Bourouiba, head of MIT's Fluid Dynamics of Disease Transmission Laboratory said in a statement. "What is the physics of the breakup telling us in terms of droplet size distribution, and the resulting prediction of the downstream range of contamination?"

This sequence illustrates the evolution of the multiphase turbulence cloud that suspends droplets emitted during a sneeze. Shown here are times ranging from 7 to 340 milliseconds post sneeze onset.

This isn't Bourouiba's first infectious rodeo, however. This research builds off of her earlier tests that show coughs and sneezes travel up to 200 times farther as these mucus balloons than if they were straight droplets. "What we saw was surprising in many ways," Bourouiba continued. "We expected to see droplets coming out fully formed from the respiratory tract. It turns out that's not the case at all. And this gives us a good baseline to expand our mechanistic understanding of violent expirations." That's all well and good, just be sure to cover your mouth first.

[Image: From the paper, "Visualization of sneeze ejecta: steps of fluid fragmentation leading to respiratory droplets," by B. E. Scharfman, A. H. Techet, J. W. M. Bush, L. Bourouiba.]