Mechanical energy nonconservative forces, like frictional forces, will be present, but often they are of negligible values and the mechanical energy's being constant can therefore be a useful approximation. In elastic collisions, the mechanical energy is conserved but in inelastic collisions, some mechanical energy is converted into heat. The equivalence between lost mechanical energy (dissipation) and an increase in temperature was discovered by James Prescott Joule. Many devices are used to convert mechanical energy to or from other forms of energy, e.g. an electric motor converts electrical energy to mechanical energy, an electric generator converts mechanical energy into electrical energy and a
Feathers: The Evolution of a Natural Miracle the byways of evolution and the wonderful world of birds." "Scientific American" published an online review of "Feathers" in their blog "Tetrapod Zoology" by Darren Naish. Naish commented that prior to Hanson's book, "it doesn’t seem that any one book has ever been devoted to feathers and feathers alone. ... "Feathers" is thus a rather significant book, and very nice it is too." Naish also stated that ""Feathers" is not the provincial view of someone only interested in ecology or conservation biology; on the contrary, this is a remarkably well-rounded review of the subject." In a review published in the