Re: Test Writing

[Herbert H Gottlieb <herbgottlieb@JUNO.COM>]

On Tue, 30 Apr 2002 10:04:43 -0500 Kossom <MKossover@NEWMANSCHOOL.ORG>
writes:
> A better question that gets at the difference between real and
> virtual images,  might ask, "Explain the difference in these two
situations.
> (a) A  slide projector creates an image on the wall that everyone can
see.
> Each  person is asked to draw a picture of the image. Everyone's
picture
> looks  nearly the same.

*** Have you tried this?  I doubt your claim that the drawings will
all look nearly the same.

b) A person looks through a magnifying glass at a
> stamp.  Another person looks over the shoulder of the first person.
Each
> person> draws a picture of what they see. The two pictures are not the
> same."

*** Do you mean that only one of the persons is looking through the
magnifying
glass? If both are looking through the same glass, at the same time, with
their heads
fairly close together why would their pictures look different?

> Instead of talking about virtual/real images, I only discuss the
> images made on the retina. They are always real. We look at how lenses
change
> the angles of the incoming rays on the lens.
***  If only real images appear on the retina,  how is it possible that
we can see a virtual image .... for example... a plane mirror porduces
a virtual image/   How are you able to see such an image when you
are shaving or applying lipstick?

Herb Gottlieb from New York City
(Where we can see  virtual images produced by our plane mirrors here)