Take a look around you. If you’re indoors, look around for the nearest flat surface. Slide your index finger over that surface and then take a look at your fingertip. Unless you just finished thoroughly dusting or cleaning the surface you just touched, you are almost certain to have picked up dust or other small particles with your finger. Because you’re reading this right now, it’s likely that you’re at home or in an office. These places are, as a rule, pretty clean places. But it’s impossible to keep things from becoming at least kind of dirty most of the time. Now imagine that you are reading this on a computer in a factory or warehouse. Given Continue reading →