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From: tgm@ukc.UUCP (T.Murphy)
Newsgroups: net.games.frp
Subject: Infravision from a physical point of view
Message-ID: <4962@ukc.UUCP>
Date: Sun, 10-Mar-85 07:24:58 EST
Article-I.D.: ukc.4962
Posted: Sun Mar 10 07:24:58 1985
Date-Received: Tue, 12-Mar-85 09:00:09 EST
Organization: Computing Laboratory, U of Kent at Canterbury, UK
Lines: 31


             I have had many arguments with my  players  as  to  the
        effect  and use of infravision.  I use the strict definition
        ``infravision is the ability to see into the infrared  spec-
        trum.''  (Players  Handbook 102).  Sadly, given this defini-
        tion Gygax goes on and imposes all sorts of rules bearing no
        basis  on this physical supposition.  Effecively infravision
        is just another colour.  The normal human eye can see in the
        electromagnetic  spectrum  from red to violet so extend this
        to from infra-red to (possibly ultra-) violet.  Things  like
        ``switching''  infravision on and off and ``concentrating on
        infravision'' and `letting your  eyes  adjust''  just  don't
        make  sense.   Your  eyes  adjust to the dark because of the
        difference in brightness, not colour.  (Just a  minute,  let
        my eyes adjust so that I can admire the blue wallpaper) Bear
        in mind that the human body with normal  clothes  on  (which
        doesn't  make  much  difference  anyway)  radiates  as  much
        infra-red light  as  a  80-watt  lightbulb  radiates  normal
        light.   You  must make the distinction that it the heat and
        not the light of a torch that spoils  infravision.   So  the
        old  trick of casting continual light on a stone and hanging
        it in a lantern should work  without  spoiling  infravision.
        Perhaps  the  most  inconceived  idea  of infravision was in
        ``Vault of the Drow'' by the great Gygax where there existed
        clocks that ``glowed green in infravision''.
        
             Just a note:  both  invisibility  and  darkness  cancel
        infravision.

                        mcvax!ukc!tcdmath!jaymin
Joe Jaquinta, c/o D.U. Mathematical Society, Trinity College Dublin, Ireland