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From: shipman@nmtvax.UUCP (John Shipman)
Newsgroups: net.physics
Subject: Re: Electric Brae
Message-ID: <933@nmtvax.UUCP>
Date: Mon, 10-Feb-86 13:23:27 EST
Article-I.D.: nmtvax.933
Posted: Mon Feb 10 13:23:27 1986
Date-Received: Wed, 12-Feb-86 21:39:10 EST
References: <736@brl-smoke.ARPA>
Distribution: net
Organization: Zoological Data Processing
Lines: 30

>    "My cousins took me to see this neat thing called the 'Electric Brae'.
>     Have you ever heard of it?  A brae is a hill, and this one has a 
>     peculiar property: it defies gravity!  We got over the crest of the
>     hill, and cousin Tom put the car in neutral; now, it should have 
>     rolled down the hill, right?  But no--the car coasted to a stop and
>     then started backing up the hill!...

Sue Stratton's story about the "Electric Brae" sounds like a tourist
trap called the "Mystery Spot" in the southwest--I can't remember where,
somewhere on I-10 or I-40 in Arizona or New Mexico?  The illusion
of the "Mystery Spot" is that gravity seems to be off vertical;
water runs uphill, you have to stand off plumb, and so forth.

Has anyone visited such a spot?  I haven't, but I remember one
of my secondary school science teachers said this was done by 
providing erroneous vertical references.  Artifacts that everyone
assumes are vertical, such as walls, phone poles, or conifers,
were all bent slightly to disorient the eye.

Driving on long rolling interstates, I have also seen an illusion
that might explain "Electric Braes".  If you drive up a long upgrade,
and it changes to a slight upgrade, it looks as if you have breasted
a hill and are now going down.

Investigators should carry a pair of spirit levels to establish true
vertical.  Plumb bobs are subject to buried magnets and should be
avoided.
-- 
John Shipman/Zoological Data Processing/Socorro, New Mexico
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