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Path: utzoo!linus!decvax!duke!phs!jtb
From: jtb@phs.UUCP
Newsgroups: net.space
Subject: Re: uiucdcs.3825: Re: Space Solar Power - (nf)
Message-ID: <2150@phs.UUCP>
Date: Tue, 15-Nov-83 10:00:46 EST
Article-I.D.: phs.2150
Posted: Tue Nov 15 10:00:46 1983
Date-Received: Tue, 22-Nov-83 00:00:03 EST
Lines: 15


In reply to your question about the reflection of heat:
All electro-magnetic radiation carries energy we call infra-red light
"heat" because we can feel the heat when it strikes our skin but we can't
see it.  Actually on a per photon basis visible light has more energy than
infra-red.  The energy traping which occurs in a room with a window or a
planet with an atmosphere occurs because some of the sun's light is absorbed
and the energy is re radiated as long wave infra-red if the glass or atmos-
phere is not transparent to this infra-red the energy will be traped.
That fraction of the light which is reflected however will pass out of the
window or atmosphere as easily as it came in.  Since most of the sun's
energy is in visible light or near(short wave)-infra red the visual reflectance
of a surface is critical in determing how much energy it will absorb.
Jose Torre-Bueno
decvax!duke!phs!jtb