Microfine

My wife was peeling an orange the other day, and every now and then a cloud of tiny particles would erupt from where she was working. It would only hang in the air for a second or so and then it would disappear. It didn't happen every time she tore a piece of peel, just on the bigger tears. I don't know whether it was particles of peel or juice. I tried taking a picture, but I was too late, and the camera was too slow.

I picked up a coffee mug to make myself a cup of tea and I noticed a line in the stain on the inside of the cup that could have been a hair. I knew it wasn't, it was too thin and it was the same color as all the other tea stain on the inside of the cup, but I couldn't restrain myself, so I wiped it with my thumb, and surprise, surprise! A big bunch of the "stain" got wiped away. This cup had just come out of the dishwasher. I got a paper towel and tried wiping away more of the stain and almost all of it came off. Not much of a stain, more like a film of superfine tea dust. I wanted some pictures, so I tried the same thing on a couple of other badly stained tea mugs, but no luck. Something about the micro structure of the surface perhaps.

My friend Marc and I were poking around in a pile of stuff he had acquired from an old tool & die shop. I found a large envelope marked as containing sandpaper with one micron grit. One micron?!?! You got to be kidding, so I open it up and pull out a sheet. It looks like paper, it even feels like paper. Well, I supposed it could be one micron grit, I mean how would you tell? There was a mold for making a curved plastic mirror there as well, and it was very smooth and shiny, just like a mirror. Is that how you get there? Cut, grind, file, and then sand, sand, sand with progressively finer sandpaper until you can't tell the difference?

Update January 2017 replaced missing picture.