Amazing that in all humanity this has never been done to scale. Then like magic this particular coronavirus can only be concerned by SD, but not the last one, or the one before that. If COVID-19 needs 6 feet / 2m of space, what do we think the distance will be when we get to COVID-23, 10m?
Perhaps this should be researched for 20 or 30 years and get back with us on the effectiveness of SD.
Cheers