As we begin to re-enter the world, we’re proceeding with caution. These days, we have a new checklist before we run out the door. What was once the standard ‘phone, keys, wallet’ check has now become ...

Viruses differ greatly in size, the smallest being about 20 nanometers in diameter to the largest measuring some 400 nanometers across. For reference, a human hair is about 60,000 nanometers in ...