Their faces plastered in blue makeup,beauty pagent contestans off stage having sex video some 3,500 people gathered in Western France over the weekend to break the record for the largest-ever crowd of Smurfs.

The next day, the French government banned gatherings of more than 1,000 people, in an effort to contain the spread of the airborne coronavirus. Overall, a leading Harvard epidemiologist told Science Vshe forecasts that 20 to 60 percent of adults worldwide will be infected (though some 80 percent of cases so far are mild, not severe).

Yet to avoid the ensuing disease (called COVID-19) which results in more severe cases than the flu, we now all know to diligently, if not obsessively, wash our hands. But there's another powerful weapon: avoiding each other as the virus expands, because it often spreads between us in the form of droplets expelled from our mouths and noses. This weapon is called "social distancing." It means keeping at least three feet away from someone, or avoiding crowds.

Social distancing, while not as extreme as staying locked inside your home (like a quarantine), is markedly more restrictive, inconvenient, and perhaps dystopian than squeezing sanitizer onto your hands. But in many places — like where you work, watch sports, or go to school — it's increasingly critical, whether you like it or not.

"The idea of social distancing is new to people," said Ashley Conway, an assistant teaching professor in the Rutgers School of Management and Labor Relations. "There is some uncomfortableness when people think about social distancing."

You want to grab drinks at a bar. You have tickets to the game. Some of your coworkers still take the train to work. Someone else is still going to the indie rock show.

"You’re trying to get people to do something they don’t usually do and they don’t want to do," Conway, the former director of the Disease Surveillance and Response Division in Calvert County, Maryland, added.

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Social distancing might be uncomfortable, but on the other hand, it works, especially when the federal government's response to ramp up coronavirus testing has been woefully inadequate and the number of infected people is uncertain. (On Monday, the University of Washington Department of Virology said, after 13 percent of a new batch of tests came back positive, "Clearly there are many people infected.")

"Social distancing goes a long way to prevent the rapid spread of the virus," said Akiko Iwasaki, a professor of immunobiology at the Yale School of Medicine. Slowing the highly contagious bug buys time to develop a vaccine or medicines.

"We really need to buy time," Iwasaki added. "If we don't do anything about this virus, the hospitals are just not going to be able to handle the number of sick people."

"Social distancing is one of the most effective tools," said Suzanne Willard, a global health expert at Rutgers School of Nursing. Sitting in a school, workplace, or sporting event surrounded by infected people near the time of an epidemic's peak can increase a disease's prevalence.

Related Video: How to properly disinfect your phone

Critically, a looming problem with coronavirus is around 80 percent of infected people have pretty mild symptoms, or no symptoms. So you can carry it, breathe it out, leave droplets on doorknobs, the counter, the work fridge —and not even feel too sickor even sick at all.

"It's mild for the vast majority of people," said Jason Farley, a nurse practitioner for the Division of Infectious Diseases AIDS Service at the Johns Hopkins School of Medicine. "But that puts us into the mindset that, ‘This is not all that bad, I might still be able to go out'."

And so the virus spreads. Typically, someone infected with coronavirus will infect two other people, Farley noted. Get ready. "We expect this to spread," he said.

So, if you're in a community with known cases (like New York City or Los Angeles), it's responsible to limit gathering with people — if your work and life allow it.

"Ultimately, if it spreads in your community, one of the first things you can do is distance yourself from others," explained Farley. Many Americans, however, aren't given sick leave and can't work from home, he acknowledged.

The robust immune systems of younger folks will better combat a potent virus that seeks to frenetically reproduce in their respiratory tract. But folks over 60 aren't so lucky, said Farley. Social distancing is meant to help the some 50 million older demographics (in the U.S.) who are more vulnerable to disease. For example, your parents and older relatives.

"Social distancing is based on the principle of altruism," he said. "Treating everyone around you like it’s your 80-year-old grandmother is the circumstance we need to think about."

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Sometimes, social distancing isn't an option. What if your employer asks you to come into work, and you must ride a crowded rush-hour train, like virtually all New Yorkers? You're in each others' faces. Then, you're inevitably exposed.

"There's no social distancing on a train car," said Farley.

"If you don't have to take mass transit, that would be great — but not everyone can do that," Iwasaki agreed.

When's a good time to start social distancing when a new, highly infectious disease has arrived in your community? Sooner than later. In the words of Michael Leavitt, the former Secretary of the U.S. Department of Health and Human Services:

"Everything we do before a pandemic will seem alarmist. Everything we do after a pandemic will seem inadequate. This is the dilemma we face, but it should not stop us from doing what we can to prepare."

"To be effective, [social distancing] should be instituted quickly," said Conway. "Once there's many cases, it’s not going to have as much of an effect."

It might not be easy for many Westerners to accept suggestions that they can't go wherever they want while an epidemic progresses. "The kind of lockdown they instituted in China was a lot easier than it might be other places — particularly in the U.S. where people value freedoms," said Conway.

But on Earth, infectious microbes are dominant. Choose wisely, even if the concept of social distancing seems inconvenient, weird, or maybe alarmist.

"I think people have the capacity to accept bad or unpleasant news and take action for the common good — even if it may be uncomfortable for them," said Conway.