Is the spacetime metric Euclidean rather than Lorentzian?

Abstract

My answer to the question in the title is "No". In support of this point of view, we analyze some examples of saddle-point methods, especially as applied to quantum "tunneling" in nonrelativistic particle mechanics and in cosmology. Along the way we explore some of the interrelationships among different ways of thinking about path-integrals and saddle-point approximations to them.Comment: plainTeX, 21 pages, 1 figure (in color). A few minor corrections and some re-wording. A previous version erroneously gave Re(f(z)) rather than Im(f(z)) (Thanks to Adam Brown for this correction.) Most current version is available at http://www.perimeterinstitute.ca/personal/rsorkin/some.papers/134.tunneling.pdf (or wherever my home-page may be