Pandemic exposes scientific rift over proving when germs are airborne

The coronavirus pandemic has exposed a clash among medical experts over disease transmission that stretches back nearly a century - to the very origins of germ theory.The Geneva-based World Health Organization acknowledged this week that the novel coronavirus can spread through tiny droplets floating in the air, a nod to more than 200 experts in aerosol science who publicly complained that the U.N. agency had failed to warn the public about this risk."WHO's slow motion on this issue is unfortuna