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Re: Virtual and Real Images



Yes you need to tilt the reflector so that the chandelier and the
observing eye are both slightly off-axis (and on opposite sides of the
axis). But do not use a screen. Observe the light from the real image
directly - (of course, the eye must be at least 10 inches beyond this real
image in order to focus on it). The striking point is that, without a
screen, the tiny chandelier floats in space like a real object.

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor
----- Original Message -----
From: "Spagna Jr., George" <gspagna@RMC.EDU>
To: <PHYS-L@lists.nau.edu>
Sent: Tuesday, March 19, 2002 2:18 PM
Subject: Re: Virtual and Real Images


Bob Sciamanda wrote, in response to Huge Haskell:
-----Original Message-----
From: Bob Sciamanda [mailto:trebor@VELOCITY.NET]
Sent: Tuesday, March 19, 2002 2:16 PM

From: "Hugh Haskell" <hhaskell@MINDSPRING.COM>
. . .
As I think about it, I recall that it is possible to create a real
image in a concave mirror, but because of the geometry, it is
difficult to display the image.
. . .
Not really difficult. . . . When at dinner, look for reflective concave
surfaces, like soupspoons, goblets, etc. Very often one can display a
diminished, real image of a chandelier floating within - or just
above -
the concave reflector. It's great dinner conversation teaching the
unwashed how to become convinced that the image is hovering in space.

It's not difficult, but you need to form an image for an off-axis object
or
use a large mirror with a small screen, else your screen will obscure
the
light from hitting the mirror in the first place.

*********************************************
"Artificial intelligence is no match for
natural stupidity."
-Anonymous
********************************************
George Spagna
Department of Physics
Randolph-Macon College
P.O. Box 5005
Ashland, VA 23005-5505
phone: (804) 752-7344
FAX (804) 752-4724
e-mail: gspagna@rmc.edu
http://www.rmc.edu/~gspagna/




Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor