Adventures in Tech

I have always wondered why most barns are painted red. It is always an aesthetic sight to see one while driving in the countryside, both during the lush green days of summer, or the yellow arid days of winter. There is of course a chance that farmers chose the color red for its aesthetics value, but I wondered if there was a more practical reason for the choice. An online search produced a bevy of results with equally reasonable choices. One of the sites argues that in the older days, one of the practical methods to seal the barn wood and protect it from the elements was to paint it with a mixture of linseed oil, and  additions of milk and line. The red color would come from adding either the blood of a recent slaughter or from ferrous oxide--rust. As the paint would dry it would turn into a dark red color. I buy the rust theory, since there is a lot of rust to be had everywhere, and the blood theory is a bit weird. The Smithsonian magazine adds a physics...