| − | |url=http://books.google.com/books?id=gvyHquVubDoC&printsec=frontcover&dq=Hedtke+The+secrets+of+the+sixth+edition&source=bl&ots=VQBk7unu95&sig=3-pYZsIj2vzBHgcIbYEpexlVc9s&hl=en&sa=X&ei=FsOGUO2kCIKJ4gS-tYCoBg&redir_esc=y}}</ref> | + | |url=http://books.google.com/books?id=gvyHquVubDoC&printsec=frontcover&dq=Hedtke+The+secrets+of+the+sixth+edition&source=bl&ots=VQBk7unu95&sig=3-pYZsIj2vzBHgcIbYEpexlVc9s&hl=en&sa=X&ei=FsOGUO2kCIKJ4gS-tYCoBg&redir_esc=y}}</ref>{{#tag:ref|cf. ''"Today we cannot see whether Schrodinger's equation contains frogs, musical composers, or morality--or whether it does not. We cannot say whether something beyond it like God is needed, or not. And so we can all hold strong opinions either way."'' Richard Feynman<ref>{{cite web |title=Miscellaneous Quotes |publisher=Duke University |
| | + | Department of Physics|accessdate=20-April-2013|url=http://www.phy.duke.edu/~hsg/quotes.txt|quote=Richard Feynman in Volume II, Section 41, page 12 of "The Feynman Lectures on Physics", 1964.}}</ref>|group=note}} |