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From: barry@ames.UUCP (Kenn Barry)
Newsgroups: net.philosophy
Subject: Re: Re: To Laura:  outlook on life and free will
Message-ID: <980@ames.UUCP>
Date: Sat, 11-May-85 11:52:38 EDT
Article-I.D.: ames.980
Posted: Sat May 11 11:52:38 1985
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Organization: NASA-Ames Research Center, Mtn. View, CA
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>   I never said treating time like a dimension was science fiction.  I said 
>that treating time as a *spatial* dimension was science fiction.  I don't
>think there is *any* reason to believe that "time is 'spacelike'" OR that
>"space is 'timelike'" so you won't get any disagreement from me there.
>
>  Maybe I'd better clarify what I mean.  Length, depth, and height are spatial
>dimensions.  They are, for all intents and purposes, the same.  They are all
>measured with the same instruments and calculated in the same units.  Time, 
>on the other hand, can only be measured by its effects (a gear turning in a
>clock, a candle burning down, radioactive decay, or whatever) and has its 
>own units.  Things move through 3-space in all different directions.  Things
>"travel through time" in one direction only.  I could go on, but I think 
>you get the picture.

	"Timelike space" and "spacelike time" are not only found in science
fiction. Current physical theory suggests that the time and space dimensions
really do swap roles in a black hole; movement through space becomes
unidirectional and constant velocity, while movement through time is
freed up. One of the ways of describing an event horizon is to say that
it's a boundary at which space and time axes get swapped around.
	Apologies to the real physicists out there for this "pop physics"
description, but I think it gives the general idea. If not, I'm sure
you'll let me know :-).

-  From the Crow's Nest  -                      Kenn Barry
                                                NASA-Ames Research Center
                                                Moffett Field, CA
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