Re: starship-design: My two cents (was Re: Battleship Galactica?)

[Steve VanDevender <stevev@efn.org>]

Kyle R. Mcallister writes:
 > Steve VanDevender wrote:
 > > 
 > > Kyle R. Mcallister writes:
 > >  > Note to physicists: Don't repeat the causality-problems
 > >  > with tachyons. Sagan, Drake, Orgel, Kardashev, et al have speculate on
 > >  > this. I think I can too.
 > > 
 > > Apparently they (and you) were speculating without bothering to check
 > > their physics.  Aside from the causality problems, a quantum mechanical
 > > analysis of tachyons shows that they can't be used for FTL
 > > communication:  either a tachyon travels FTL, but doesn't interact with
 > > our universe, or it doesn't travel FTL.
 > 
 > I did not know this. Can you reccomend where I could get information on
 > this?

There's a brief article with a more detailed analysis of tachyons at:

http://sunsite.unc.edu/lunar/school/library/tachyons.html

It's an excerpt from the sci.physics FAQ, which is also good reading.

 > > Authority counts for nothing in science.  Just because an authority
 > > speculates about something doesn't mean it's true.
 > 
 > I suppose thats true. It was just an example though.

There is certainly a possibility that more advanced civilizations use
communications methods that we can't detect at multi-light-year
distances.  Even our civilization is starting to use methods that
radiate less to the universe (cable, lasers, etc.).