Why Are So Many American Barns Red?If we start at the beginning then we need to talk about star birt
Why Are So Many American Barns Red?If we start at the beginning then we need to talk about star birth. Not just any star, and not a living star; these stars (note the plural) have been dead for probably billions of years. But while they were living they did some pretty incredible things. Most importantly to our topic, they made iron.When a star is born it’s just a big ball of gas. There are some light elements floating in space that cluster together due to gravity, pulling each other in until they fuse, transforming hydrogen into the heavier element helium, for instance. These heavier elements are also floating around, but because of their weight they huddle a little closer (again due to gravity). As they do so, the temperature and the pressure inside the star continues to increase until they, too, fuse, forming an even heavier element. And the cycle continues.This happens in all stars until a very specific threshold is reached. Stars don’t create elements with more than 56 nucleons (or a total of protons and neutrons). Why? Because at this point there needs to be a net input of energy to create newer, heavier elements, energy which the sun just doesn’t give. What is the most stable element with 56 nucleons? Iron. Stars produce more iron than anything else, and therefore iron is super abundant.What on earth does all this star stuff have to do with red barn paint? Red paint is made from red ochre (Fe2O3), or anhydrous iron oxide. This is the stuff that makes the red paint red, thanks mainly to the way iron absorbs and reflects light. Because there is so much iron in the universe (and probably beyond) and therefore on earth, red ochre is extremely cheap, making the paint relatively cheap. And who wants to paint a cow barn with expensive paint?In a delicious twist of fate, one of the more common adornments on American barns is the “barnstar”, considered a “lucky omen” similar to a horseshoe over a doorway.Further reading: http://www.smithsonianmag.com/smart-news/barns-are-painted-red-because-of-the-physics-of-dying-stars-58185724/?no-istPicture credit: Dave Smith https://www.flickr.com/photos/skimerlin/-Colter -- source link
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