Message-Id: <v03102800affc1d3e5402@[146.186.17.49]>
In-Reply-To: <n1342506221.9067a@Tesla.exploratorium.edu>
Date: Wed, 23 Jul 1997 17:01:10 -0400
To: "Pinhole Listserv" <pinhole@exploratorium.edu>
From: Dave Nickles <dan7@psu.edu>
Subject: Re: Pinhole Daily Digest
A question of reflection to reflect upon.
I was presenting an elementary teacher workshop on light reflection today
and asked the questions: "How tall must a (normal) mirror be, mounted flat
against the wall, in order for a person to see their whole body (head to
toe)? Does the distance from the mirror play a role?"
I maintained that the distance away from the mirror does not matter, that
the height of the mirror must be approximately one-half the person's
height, and that the top of the mirror should be approximately level with
the top of the person's head.
We seemed to find this answer suitable through experimentation with
different size mirrors and distances away from the mirror. However, there
were two high school physics teachers in the room who insisted that
distance DOES matter, one giving the example of looking through a relector
telescope and being able to see the moon (and comparing that to my mirror
question) and, that if a person looks in a mirror s/he can observe the
entire moon, which is very large, because it is so far away, so odstance
MUST matter. I think THEY have the misconception, but I'm not sure and
intuitively we are all experiencing cognitive conflict even after "seeing"
the evidence. They maintained that if we got a mirror far enough away from
the observer then the only problem with the observer seeing his/her whole
body in the mirror would be our inability to see oneself from such a great
distance (they suggested using binoculars to look back at your reflectin in
the mirror!)
I think their responses are addressing a different question, but couldn't
argue against their position on the spot. I'd like to know what advice
pinhole folks have to offer. I am presenting this workshop 'till Friday and
if I could get your responses on Thursday, I could share them with the
teachers. We all want to know!
Thanks!!!
Dave Nickles
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Dave Nickles
Science Education
177 Chambers Bldg.
Penn State University
University Park, PA 16802
814-863-1691 (office)
814-861-2093 (home)
dan7@psu.edu
personal homepage is http://www.personal.psu.edu/users/d/a/dan7/
Thought of the Week:
The Genesis of Ideas
"Some weeks or months go by, and then, suddenly, an idea that represented a
solution to the problem or the germ of a solution to the problem would
burst into my unconsciousness."
Linus Pauling (1963)
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