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

*To*: starship-design@lists.uoregon.edu (Starship list)*Subject*: Re: starship-design: FTL*From*: kuo@bit.csc.lsu.edu (Isaac Kuo)*Date*: Wed, 27 Aug 1997 10:19:14 -0500 (CDT)*In-Reply-To*: <199708262207.PAA31144@tzadkiel.efn.org> from "Steve VanDevender" at Aug 26, 97 03:07:45 pm*Reply-To*: kuo@bit.csc.lsu.edu (Isaac Kuo)*Sender*: owner-starship-design

Steve VanDevender wrote: >First of all, I'm not entirely sure what you mean by a negative time >value. The only observer-independent notion of time in relativity is >"proper time", i.e. the time that an object experiences itself. In at >least one (probably oversimplified) analysis, FTL motion requires that >the object experience _imaginary_ proper time. It is an oversimplified analysis. It starts off with the very erroneous assumption that FTL frames of reference are enough like STL frames of reference that the equations derived about STL frames of reference can be applied to FTL frames of reference without modification. In particular, some of you are familiar with Einstein's derivation in special relativity of how the passage of time is measured--it's measured by using a clock. The one he uses is a simple "light clock" (two parallel mirrors have a photon bouncing between them and the number of times the photon bounces ticks off time), but the passage of time on even this simple clock reflects the passage of time for everything else (like mechanical clocks, atom clocks, chemical reaction times, etc). The shocking thing about FTL frames of reference is that not even this simple light clock works! In an STL frame of reference, the miracle is that with a Lorentz transformation, the light clock will measure time the same no matter how it's rotated (e.g. whether they are perpendicular to or parallel to the direction of motion is irrelevant). In an FTL frame of reference, the light clock measures time differently depending on how it's rotated--in some angles, time doesn't seem to pass at all (the photon can't catch up to the other mirror)! Therefore, the equations for time dilation, which are derived from the light clock and the Lorentz transformation, simply are not valid for FTL frames of reference. No wonder they spit out a nonsensical notion like time passing in an imaginary direction! In order to analyze FTL frames of reference, you have to go back to basics--the Lorentz transformation. -- _____ Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo __|_)o(_|__ /___________\ "Mari-san... Yokatta... \=\)-----(/=/ ...Yokatta go-buji de..." - Karigari Hiroshi

**References**:**RE: starship-design: FTL***From:*Steve VanDevender <stevev@efn.org>

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