> > > I've almost certainly misunderstood this quote, but how can a mask > possibly cause a single photon to cast a shadow? A shadow is just the > contrast between high and low light areas, so with a single photon how can > the shape of this area be defined? Sounds like a relative of the two-slit experiment, in some ways. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist