Scientists have found "unambiguous evidence" that the coronavirus can float in the air and infect cells.

A team of virologists and aerosol scientists successfully isolated live virus from aerosols collected up to 16 feet away from patients hospitalized with COVID-19, much farther away than the recommended six feet of social distance, reported the New York Times.

“If this isn’t a smoking gun, then I don’t know what is,” tweeted Dr. Linsey Marr, an expert in the airborne spread of viruses but was not involved in this study.

Researchers at the University of Florida managed to collect air samples from a room in a COVID-19 ward, but nether patient had undergone medical procedures known to generate aerosols, which are believed to be the primary source of airborne infection in hospitals.

The team collected samples from seven feet away and 16 feet away, and they found virus samples genetically identical to samples taken from the patients had been able to infect cells in a lab dish.

They found only 74 virus particles per liter of air because the room had six air changes per hour and was outfitted with special equipment intended to inactivate the air returning to the room, but even that sample was able to cause infections in the lab setting.

“I’m just not sure that these numbers are high enough to cause an infection in somebody,” said Angela Rasmussen, a Columbia University virologist.

“The only conclusion I can take from this paper is you can culture viable virus out of the air,” she added. “But that’s not a small thing.”