Mechanical energy swing because of the work done by the pendulum to oppose these non-conservative forces. That the loss of mechanical energy in a system always resulted in an increase of the system's temperature has been known for a long time, but it was the amateur physicist James Prescott Joule who first experimentally demonstrated how a certain amount of work done against friction resulted in a definite quantity of heat which should be conceived as the random motions of the particles that comprise matter. This equivalence between mechanical energy and heat is especially important when considering colliding objects. In an elastic collision,
Feathers: The Evolution of a Natural Miracle Adult Science Book category, presented by the American Association for the Advancement of Science and Subaru. "Feathers" was listed among the top ten best books of 2011 in the Sci-Tech category by the "Library Journal". "Feathers" received the John Burroughs Medal in 2013, which is awarded annually by the John Burroughs Association to "the author of a distinguished book of natural history". Reception to "Feathers" has been positive. Amanda Katz, in a review published by "The New York Times", wrote that because "Feathers" is a work of synthesis, bird enthusiasts will find the book's content already "familiar", but noted that