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Re: starship-design: FTL and time travel

Kyle R. Mcallister wrote:

>Can you tell me the difference between negative mass
>and imaginary mass? I couldn't find it in Spacetime Physics

First off, the very basics: are you familiar with complex numbers
and mathematics with complex numbers?

If not, then you won't be able to grasp the notion of imaginary
numbers.  Suffice it to say that you need to learn about complex
numbers first (it's interesting stuff), and that in the meantime
realize that imaginary numbers are not "real" (umm...there's no
way to say that without it being a pun).
>> Sorry, you just don't understand.  It depends upon how much you
>> accelerate away from Earth before returning.  

>Ah, I see now. Is this in Spacetime Physics?

I'm not familiar with that reference, unfortunately.

>> I won't go through
>> all the calculations, because you won't understand them.  Not
>> without drawings of space-time diagrams, at least, which really
>> can't be drawn in ASCII.  Jay Hinson's FAQ on relativity and FTL
>> does a noble attempt at it (he regularly posts it on rec.arts.sf.
>> startrek.tech and rec.arts.sf.science less regularly).

>How can I get on one of these newsgroups?

The flippant answer is that you can either use a newsreader or read
"usenet" via www.altavista.com or www.dejanews.com (highly undesireable
on a regular basis).

A more helpful answer would depend upon what sort of internet access
you have.

First off, assuming you have a web browser, a search in
www.altavista.com (searching "usenet") or in www.dejanews.com
(which only searches usenet) should find Jay Hinson's FAQ on
relativity and FTL pretty easily.  In fact, you'll want to
search Usenet for other topics--often the pages you find will
be more informative than trying to search the web.

Secondly, assuming you use your web browser to read e-mail, simply
activate the "news" window, and you should be given an interface
to read usenet netnews which is a bit like the e-mail reader.

Third, if you are using a Unix shell account to access the Internet,
you may be stuck with using a text newsreader, like "trn" or "tin".
Try typing "trn" or "rn" at the command line.  If you're lucky,
"trn" will already be installed on your system.  The bad news is
that it's a text based reader, and you'll have to learn keyboard
commands.  The good news is that "trn" is the most powerful
newsreader around, is easy to learn (just remember to press "space"
when you want it to automatically guess what the best next thing
to do is, or press "h" when you want to know what your other options
are), and is simply a lot faster and pleasant to use in the long
run than Netscape or any other web browser.

(Actually, that's bad news.  Why can't anyone make a graphical
news reader as fast and powerful as trn?)

Anyway, I'm sure you'll find searching Usenet netnews to be
interesting and informative, at least.  Just remember to beware
of anything you read!
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
/___________\ "Mari-san...  Yokatta...
\=\)-----(/=/  ...Yokatta go-buji de..." - Karigari Hiroshi