title: Classical physics and quantum loops.
abstract: The standard picture of the loop expansion associates a factor of variant Planck's over 2pi with each loop, suggesting that the tree diagrams are to be associated with classical physics, while loop effects are quantum mechanical in nature. We discuss counterexamples wherein classical effects arise from loop diagrams and display the relationship between the classical terms and the long range effects of massless particles.
authors.affiliation: Department of Physics-LGRT, University of Massachusetts, Amherst, MA 01003, USA.
authors.forename: Barry R
authors.initials: BR
authors.lastname: Holstein
authors.forename: John F
authors.initials: JF
authors.lastname: Donoghue