On Fri, Oct 26, 2018 at 5:40 PM <agrayson2...@gmail.com> wrote: *> the concept of a plane wave, one of the solutions of Maxwell's > equations. It certainly doesn't exist in THIS universe*
I agree with the general point you're trying to make, just because something can be consistently described mathematically doesn't prove it must exist physically. However if you're interested in the waves that enter your radio telescope and consider them to be plane waves the error in doing so can be made arbitrarily small by increasing the distance from the point source or by decreasing the size of the antenna. As a practical matter because the things astronomers study are so distant and their antennas are so small they can treat the waves they're interested in as plane waves and produce no measurable error by doing so. But a designer of optical microscopes would not have that luxury because the lens of a microscope is large compared to the distance from the sample, so he could not treat them as plane waves. John K Clark -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To post to this group, send email to everything-list@googlegroups.com. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
