"The distance itself appears to be somewhat arbitrary, and varies from 1 meter in parts of Europe, to six feet in the US, which makes me doubt the scientific ba

"The distance itself appears to be somewhat arbitrary, and varies from 1 meter in parts of Europe, to six feet in the US, which makes me doubt the scientific basis" This seems quite a black and white way to look at things. Would you agree that it you are more likely to catch the virus from an infectious person if your face is 6 inches from theirs, vs. being a mile away from them? A reasonable conclusion about the difference between Europe and US recommendations is not that their science is different, but that they are simply setting the threshold for acceptable risk at a different level, and that the risk increases with proximity. They are trying to give meaningful advice while keeping it somewhat simple. 6 feet away is safer than one meter away. If you come close to someone, it is safer if it is for 5 seconds rather than for 20 seconds. If you can hold your breath during that period, all the safer. It is safer if you are facing away from one another. It is safer if neither person is talking, coughing or sneezing. Whether there is a breeze and which way it is blowing is significant. And so on. There is never going to be a hard cutoff for things like this. Sometimes there is a place for common sense, reasonable inferences, and balancing of priorities and risks.