"In the last 24 hours, a computer simulation by a team of Belgian engineers that tracks the 'spread droplets' and 'slipstream' of the exhalations, coughs, and sneezes of people who are running, walking, or cycling has gone viral."

"Perhaps you have seen this gif on Twitter, Facebook, or NextDoor. Or, as some people on our staff have seen, perhaps write-ups of it have been texted to you by concerned friends or family. Though this was not the specific goal of the simulation, it is currently being used on neighborhood groups and social media as scientific evidence that people who are jogging and biking are putting others at risk. If you are getting 'droplets' or 'globules' on you, the thinking goes, you are at risk of contracting coronavirus. 'People should read and not misread my tweets and texts,' Bert Blocken of Eindhoven University of Technology, the lead researcher on the simulation, wrote in an email to Motherboard. 'I have never and nowhere discouraged people from walking, running, or cycling. Rather the opposite. Maybe people should read more, and react less.'"

"The Viral ‘Study’ About Runners Spreading Coronavirus Is Not Actually a Study/Belgian researchers chose to bypass all standard science publishing protocols to publish research that has been overhyped and isn't well understood" (Vice).

Yeah, I got that thing texted to me. I think people who are sheltering indoors are hot to drag others indoors.

Blocken has yet to publish a peer-reviewed paper about the simulation. In fact, he hasn't even published a non-peer-reviewed study.... Given what Blocken has put into the world, taken at face value, some people are understandably concluding that it is impossible to run or cycle safely in many cities; he recommends a distance of 65 feet between bikers and other people, something that is impossible to do in cities. The issue with Blocken’s suggestion that we “read more, and react less” is that there is almost nothing to read, and there is no study to critique....
On Facebook and Twitter, the article is being shared in neighborhood groups and is being used to spur a battle between pedestrians and runners and cyclists. A typical comment is something like this, shared in an Iowa City "Quarantine Survival" Facebook page: “Omg people keep doing this. Runners and bikers with zero regard for fellow pedestrians 🤬🤬”...

I showed Blocken's research to William Hanage, an epidemiologist at Harvard's Center for Communicable Disease Dynamics. He said that the virality of Blocken's research is harmful, and that Blocken's suggestion in the white paper that this research is a "modest contribution" toward the fight against Covid-19 "makes my blood boil." "Where the droplets are is much less relevant than the amount of transmission that occurs via this route."

Crucially, scientists are still unsure how well the coronavirus spreads in the air, and many have cautiously speculated that the overall risk of transmission appears to be less outdoors. Globules and droplets do likely carry the virus, but that doesn’t mean that anyone who gets a droplet on them from someone’s breath is going to be infected. Transmission depends on a host of factors; scientists believe an important one of these is “viral load,” which is a measure of how much of the virus is present....