Re: Active vs Passive

"Robert W. Hofrichter" wrote:
> 
> One problem with EMCON, though--don't fusion piles produce neutrinos? 
(I
> seem to remember something of the sort from a physics --or was that
> astronomy?--class years ago.)

	Yes, they do. I recall some calculations (done for a
Traveller-based
game, from the designer's notes, url at
<http://www.grognard.com/info/brillanc.txt>), that essentially found
that for a hydrogen fusion reaction, a neutrino detector will detect, on
average, 10^-21 neutrinos/second (per ton of detector per watt of the
fusion plant). Thus, given a 1,000,000 ton detector (10,000 TMF) and a
100,000MW power plant (VERY large), on average one neutrino would be
detected every 26 minutes. Just TRY and build up a sensor track from
that much information.....
	You'd be better to detect the heat which such a plant will have
as a
byproduct. Again, with current technology (although I've unfortunately
lost this url), a ship-based infrared telescope could probably detect a
working fusion plant millions of km away simply from waste heat (yes,
you could probably store the heat somewhere, but the effort of keeping
the temperature of the outer hull more than 200 degrees lower than the
inside (so that the people on board don't freeze) seems essentially
impossible).

> A low-tech force using chemical rockets for propulsion (advanced ones,
of
> course, but still limited thrust duration due to fuel requirements)
facing
> off against a super-high-tech force (which, having been trained in
fighting
> other super-high-tech forces doesn't recognize the threat in time)
using
> fusion piles for power and some high-tech propulsion.  Result?  Some
very
> stealthy ships that are easy to destroy but very hard to find fighting
very
> fast, hard to destroy ships that stand out like strobelights in a dark
room.
> Might be fun...

	Well, the difficulty is that chemical rockets put out a LOT of
energy,
much of it visible (and CERTAINLY detectable by telescopes). Hell, if
your drive uses reaction mass, and provides 0.1g or more of thrust, it
could probably be detected at least a billion km away. Of course, the
more efficient your drive, the higher its exhaust temperature, the
easier it is to detect, but ANY ship using it's drive is going to stand
out like a strobelight. Of course, your drive may not use reaction mass
(although I'm not inclined to assume reactionless drives), but even so
you'll need SOME source of power. Essentially, I don't think that
effective combat range will even APPROACH 10,000,000 km by 2183 (see the
above url for information on trying to focus lasers at MUCH lower
distances), but I also don't see how you can AVOID detecting a ship at
that range if you're trying at all. Yes, ECM/ECCM/etc. will be useful
when you're already fighting (hitting someone at long range, even with
speed-of-light weapons, isn't easy), but I think that it'll be fairly
obvious WHERE the ships are (or, at least, were x seconds ago, thanks to
the lightspeed delay).

-Brian Quirt