New York based artist Sally Davies has been photographing one McDonald’s burger-and-fries Happy Meal, that she bought on April 10, 2010, every day for the last 137 days. Other than a little patty shrinkage, the burger look essentially the same.

Davies plans to keep going with the project until something happens, but she has no idea what she is getting into. A few years ago, a twelve-year-old McDonald's burger surfaced that looked shockingly well-preserved. Again, earlier this year, a blogger left a McDonald Happy Meal exposed for a year and found it mostly unchanged. Sally Davies experiment is the closest thing we’ve seen to transparent scientific documentation on the subject, and provides terrifying evidence that McDonald’s burgers are worst possible thing you can put in your body.

According to McDonald’s website, the only ingredients in the McDonald’s beef patty are “100% pure USDA inspected beef; no fillers, no extenders. Prepared with grill seasoning (salt, black pepper).” The buns do, however, contain the preservatives sodium and calcium propionate, and McDonald’s French fries contain citric acid and tert-Butylhydroquinone as preservatives. However, we do believe, that there are some terrible preservatives in that thing that could keep it so well preserved for years.

There are other evidences of McDonald’s indestructible burgers. University of Nottingham chemistry professor Martyn Poliakoff dunk the whole thing in a vat of concentrated hydrochloric acid. Hydrochloric acid, as you must know, contains in every person’s stomach and helps in breaking down of the food molecules. The hydrochloric acid in the stomach is very diluted. But see what happens when you put the burger in concentrated hydrochloric acid.

[via Refinery29 and Geekosystem]