Re: SR examination question

[brian whatcott <inet@INTELLISYS.NET>]

Would it compound the confusion to offer a usual formulation of time
dilation in words, which goes like this:
"If two observers are moving at constant velocity relative to each other,
it will appear to each that the other's clock has been slowed down."

Using the ratio  1/(1-v^2/c^2)^0.5 =0.44 for v = 0.9c
we suppose that each sees the significant other ticking at 44% of
the personal rate, and each can notice that the other's watch will
 indicate the passage of one minute while the local watch indicates
 1 min/44% = 2.3 minutes have elapsed.

Or to put it another way, the local watch indicates the passage
of one minute while the remote watch is seen to indicate the passage of
1 min X 44% = 26 seconds.

This seems like a more reasonable formulation to me, in so far as
any of these relativistic constructions is reasonable - but I am
prepared for the awful realisation that comfort with descriptions
of mind experiments may be a personal thing.

Brian

At 14:28 5/17/01 +0200, Mark wrote:
> My difficulty is perhaps simpler. The question refers to what Peter
> observes and asks what Jane observes. Both sound to me like descriptions of
> a proper time interval, and I don't know in which reference frame to place
> myself to answer the question. I often find this difficulty in basic SR
> problems. Am I missing something, or is it that ambiguous questions are
> common in this area?
>
> Mark
>
> At 07:07 17/05/01 -0500, brian whatcott wrote:
> > At 12:27 5/17/01 +0200, you wrote:
> > > Am I correct in thinking that the following simple question is
inadequately
> > > specified?
> > >
> > > Peter and Jane are each wearing a wristwatch with a second hand that takes
> > > one minute to make one complete revolution and Peter is moving at a speed
> > > of 0.9c with respect to Jane. When Peter observes the second hand on his
> > > watch to have made one complete revolution, how many revolutions will Jane
> > > observe the second hand of her watch to have made?
> > >
> > > Mark
> > >
> > > Mark Sylvester
> > > UWCAd
> > > Duino Trieste Italy
> >
> > What time is observed to elapse in a frame moving at 0.9c with respect to
> > a frame where one minute elapses?
> >
> > According to Ronald Mallett UConn, at least, this is an indeterminate
> > question,
> > in that one of the observers might be circling the other slowly,
> > and traveling backwards in time.
> >
> >
> > brian whatcott <inet@intellisys.net>  Altus OK
> >                 Eureka!
>
> Mark Sylvester
> UWCAd
> Duino Trieste Italy
brian whatcott <inet@intellisys.net>  Altus OK
                Eureka!