Re: Avoiding the Void

Nick Wedd writes:
> "Frame-dragging"?  That is not something I have seen mentioned in 
> physics texts.

It's one o'them thar relativistic thingies.

> But I admit that it exists - you can frequently observe 
> it on a railway platform.  As a train pulls to a stop, the people on the 
> platform who were waiting for that train tend to drift in the train's 
> direction of motion.

Sure, because...

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People who have reserved seats will tend to remain stationary until the
train stops *or* until the car where their seat is goes by, and in the
latter case, they'll start moving to be nearer that car when it stops.
Similarly people who are looking for the only first-class car, or the
only smoking car if on a railway that still has them.

People who don't have reserved seats, or passengers on systems like urban
transit railways where there are no reservations, will scan the cars as
the train stops, looking for one with enough empty seats (or at least
enough standing room).  If they see one that looks good, they'll start
moving so as to be nearer it when it stops.

This won't apply on all systems or at all stations, of course.  Regular
travelers on a line will know if one part of the train tends to be less
loaded than another, and the flow along the platform at any particular
station may be determined mainly by where its entrances and exits are.
-- 
Mark Brader, Toronto                        "Sex on trains, of course."
[EMAIL PROTECTED]                                         -- Clive Feather

My text in this article is in the public domain.