I've always thought that these "recommendations" were just the best guesses at the time. I didn't think they were "scientific". I thought it was obvious to ever

I've always thought that these "recommendations" were just the best guesses at the time. I didn't think they were "scientific". I thought it was obvious to everyone. Who is going to volunteer to stand 1,2,3,4,5,6 ft away and test whether covid infection happens in March 2020? What scientific evidence could we have come up with in such a short notice?