🚀 go-pugleaf

brian@helium.ssc.gov (Brian Scipioni) writes:

>I know the twin paradox has been beaten to death, and I know what the
>mainstream viewpoint is. It is simple and straightforward to understand.

>My problem continues to be the unsupported assertion that information - 
>which does not contain matter or energy - travels, and is limited to the
>speed of light. You can send information using light if you like, but the
>speed belongs to the light.

     It seems to me that information, which determines future events, must
     be constrained by the speed of light.  Otherwise you may be stuck with
     having the information and not being allowed to act on it.

>You can also use your observations coupled with a knowledge of physical
>laws to deduce information about events not directly accessible to
>you through observation.

     But there is one very basic assumption inherent in this -- do the 
     conditions at this remote point remain as they were the last time
     you were in physical contact?  If yes, then you can make some accurate
     predictions of what is going on there.  If not, or if one has a very
     complex system (like a human being, for example), then the same 
     predictions would be made, but they would be figments of the predictor's
     imagination.

     For example, in this twin-paradox discussion that sparked this, it is
     very nice to be able to say that my calculated surface of simultaneity
     says that right 'now' John is age X.  However, John was in actuality run
     over by a raging bull in a china shop at age X-1, so the prediction
     made in no way reflects reality.

     That required assumption destroys the validity of the prediction.
     After, you can only check the prediction via the constraint of the
     speed of light.  You could act on a prediction and hope that it is true,
     but that becomes educated guesswork.

>When information is created does it have a location? Does it appear throughout
>the universe at once?

     In the above example, the information that John died is very much a local
     effect and is propagating outwards at the speed of light at best.  One
     may predict all they want, but it just ain't real.

--
Arnold Gill --- astrophysician trainee in exile             gill@physics.ubc.ca