Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!uwvax!shorty!matt
From: matt@shorty.CS.WISC.EDU (Mad Matt Schaefer)
Newsgroups: sci.misc
Subject: Re: quick question
Summary: oops, I take that back.
Keywords: point of view
Message-ID: <5137@spool.cs.wisc.edu>
Date: 29 Jan 88 05:08:37 GMT
References: <1170@petsd.UUCP> <73600006@uiucdcsp> <6730@agate.BERKELEY.EDU> <3508@batcomputer.tn.cornell.edu> <5127@spool.cs.wisc.edu> <20215@bbn.COM>
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Reply-To: matt@cs.wisc.edu (Mad Matt Schaefer)
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In article <20215@bbn.COM> cosell@bbn.com (Bernie Cosell) writes:
>In article <5127@spool.cs.wisc.edu> matt@cs.wisc.edu (Mad Matt Schaefer) writes
>>[ ]
>>the forehead and one on the nose, then front/back reversal would cause top/
>>bottom reversal. Or something like that.
>
>Does that mean that if you close one eye there'll be no reversal at all? :-)

As I went to sleep the night after I posted the article about the eyes, I
thought the same thing and decided that what I had posted was utter BS. I
guess that will teach me to post without sleep. Anyway, I say there is no
left-right reversal with respect to the person looking in the mirror, since
as was pointed out earlier, if you point to your left, your image points to
*your* left as well. However, if we compare the images, we get both horizontal
*and* vertical reversal. Let's say you take a camera and take a picture of
yourself looking in a mirror. Let's say, for the sake of demonstration, that
your image's camera takes a picture of you at the same time. After the film
is developed, we take the two pictures and place them side by side with both
heads on top. There is left-right reversal, as if there was only one picture
with a mirror perpendicular to it at its side. Then take the two pictures and
put them head-to-head. There is top-bottom reversal, as if the perpendicular
mirror was on the top of one picture. So depending on your point of view
(I wonder what your image sees ;^) there is either no reversal or total
reversal.

Matt Schaefer                      ...!{harvard,ihnp4,rutgers,ucbvax}!uwvax!matt
UW-Madison Computer Sciences Laboratory                         matt@cs.wisc.edu