We all know that standing six feet away from other people can help us avoid catching or spreading COVID-19. Ever since modern medicine began, we knew fresh air and good airflow helped promote health. But, where exactly did we get the number six feet? Why is a six-foot gap better than a five-foot space, and why isn’t it seven?

In an editorial, Joseph Allen is director of the Healthy Buildings program at Harvard T.H. Chan School of Public Health, wrote: “Six feet is good, but 10 feet is better.” That shows that there are disputes about how far apart we need to be. It also varies by activity. The farther away you are from someone else, the better. And, obviously, if you are 100 feet away from someone, you won’t catch their COVID-19 or give it to them if you have it. So Why does everyone say six feet?

The guidelines vary by country. Some Countries measure in meters and say that one is fine. Canada, Spain and the U.K. call for two meters. The U.S. says six feet (1.8 meters). COVID-19 can travel through spit and small particles as you speak, cough, sneeze or breathe. Our rules, no matter what country a person is in, are based on research from the 1930s. They found that most droplets of liquid from a cough or sneeze fall to the ground or evaporate within one or two meters. Smaller particles travel farther. The research was from Harvard, and so is probably reliable, but we would really like an update. It’s been almost 100 years, and we’d like to know more about their methods.

The current concern is that tiny particles can travel about six meters (almost 20 feet). And, scientists have figured out how long the virus can live on different materials, but now how long it survives in the air. Research takes time, and COVID-19 is still a new virus in terms of how long a study takes.  

Until we know more, six feet seems like a good guideline until we get more studies on the virus. If you have a hard time picturing it, It’s a little more than an average-sized person’s arm span. If you and a person could touch: you’re too close. Other examples include the length of two shopping carts, the width of a car or the height of many professional basketball players!

If you want to spend time with people, heading outside is a good idea. The air circulation is better for keeping particles away from you. The farther away from people, the safer you are. That’s not always a possibility, but it’s better to keep as much room as possible. Air hugs and air fives are the best way to greet a friend until we have more answers.