[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: <lparker@cacaphony.net>*Subject*: RE: starship-design: Relativity*From*: Steve VanDevender <stevev@darkwing.uoregon.edu>*Date*: Tue, 11 Jan 2000 17:07:02 -0800 (PST)*Cc*: <starship-design@lists.uoregon.edu>*In-Reply-To*: <000501bf5c96$e2904a20$0401a8c0@broadsword>*References*: <14459.51916.183572.902355@darkwing.uoregon.edu><000501bf5c96$e2904a20$0401a8c0@broadsword>*Reply-To*: Steve VanDevender <stevev@darkwing.uoregon.edu>*Sender*: owner-starship-design@lists.uoregon.edu

L. Parker writes: > I kind of thought so... > > Okay, first question: > > If the limit of T (the time required to go from point A to point B) as v > approached c equals zero, why isn't the limit of ABbar (the length of the > worldline) as v approaches c equal to zero? I sort of understand how and why > it is actually shorter even though it isn't a straight line, but why doesn't > it go to zero as v approaches arbitrarily close to c? Or have I simply not > read far enough yet? Maybe I'm just totally confused? > > Lee Is this in reference to a particular exercise or passage in _Spacetime Physics_? If so, which one? It would help me understand the context. I hope you have the second (1989) edition; otherwise it may be a bit hard to connect with the copy I have. It depends on what you mean by "the length of the worldline". The definition that is invariant for all observers is that the "length" of the worldline (typically called the interval in _Spacetime Physics_) is is equal to the elapsed time experienced by the object that travels along that worldline between event A and event B. Depending on their relative velocities to that object other observers will see event A and event B as being different distances from each other and the object as taking different amounts of their time to travel from event A to event B. The ratio between the amount of time shown on a clock carried with the object and the amount of their time they measure for the passage from point A to point B goes to zero as the relative velocity of the object approaches c.

**Follow-Ups**:**RE: starship-design: Relativity***From:*"L. Parker" <lparker@cacaphony.net>

**References**:**Re: starship-design: Relativity***From:*Steve VanDevender <stevev@darkwing.uoregon.edu>

**RE: starship-design: Relativity***From:*"L. Parker" <lparker@cacaphony.net>

- Prev by Date:
**Re: Re: starship-design: Relativity** - Next by Date:
**RE: starship-design: Relativity** - Prev by thread:
**RE: starship-design: Relativity** - Next by thread:
**RE: starship-design: Relativity** - Index(es):