AMID THE HOURLY updates on the new coronavirus, a single, calming fact stands out: a particle of happy news, hanging in a cloud of dread. The germ that causes Covid-19 may be responsible for a terrifying public-health disaster, but hallelujah, thank the lord, at least it isn’t airborne.This message is now dogma for news outlets and public health officials. They impress on us that droplets laced with the new coronavirus don’t remain aloft for long—that they only sail for six feet at the most before they fall onto the ground. That’s why we’re told that soap and water are the best protections one can find: 20 seconds’ worth of hand-related hygiene, repeated many times throughout the day. The virus isn’t airborne; so keep on washing when you can. The virus isn’t airborne; so you’d be wise to trade your grubby handshake for an elbow bump. The virus isn’t airborne; so don’t forget to keep your fingers off your face.