RE: Fusion Drives
I've been listening to this debate about Fusion Drives as weapons, and I see
quite a bit of silliness on all sides...
A: This talk about needing every city and ship have force fields to protect
them from fusion drives takes the cake! It's a *major* change to the game
and basically allows any amount of handwaving and pure magic.
B: While I'm certainly no authority on the shape of the discharge from a
fusion drive, I doubt that it's either a fireball, or tens of kilometers
long. While we don't have any fusion drives in real life to compare, we
should be able to extrapolate.
Do any of the highest specific impulse or thrust rockets show any sign of
cutting through air, forming a fireball instead? What exactly is the
difference between the chemical rocket and chemical explosive that makes
one produce a straight line exhaust, and the other a fireball?
My first guess says that whatever the difference is between a rocket and a
bomb, the same difference will apply to a fusion as well as a chemical of
fission rocket and bomb. EG fusion drives will not have fireballs.
Second Idea: What happens if we try to approximate a much higher energy
fusion exhaust, with thinking about what a lower energy exhaust does in a
denser medium, IE what happens when you try to run a rocket under water?
Does it create a fireball, or a straight exhaust? My guess is that it
would not work all that well. I haven't seen any jet subs or torpedos
around here. This leads me to believe that a fusion drive in atmosphere
might well be a bad idea.
Idea three: Is it possible to tune the shape of the exhaust from the
fusion drive. As this is done with chemical rockets and jets, I'm sure
that it can be done with fusion drives. So you ought to be able to produce
something in between the extremes of a fireball and a relatively long
danger space behind every fusion drive. Maybe it is only dangerous for
a fraction of a Km. I imagine that the highest effeciency has the longest
dangerous exhaust, but it should be possible to tone it down when necessary
in the atmosphere. Remember, nobody's going to like you waving your ten Km
exhaust around even in orbit if it's a busy place!
Next: Needing to use the fusion drives in the atmosphere isn't even
necessary. I think that Bertil's idea of using the Contra-Gravity to
control descent and ascent is ideal. Having a limit of plus and minus one
or two G seems to me to contrainst this nicely.
Add the SCRAM jets which are also used as thrusters in space and you have
all that you need for planetary maneuvering without any extra equipment or
hocus pocus. The SCRAM jets are *very* simple, feed whatever as fuel in,
heat it with the basically unlimited power from the power plant, and viola!
action/reaction.
Now, I would expect that ?some? space ports would have ?some? hardened
landing pads and blast deflectors that would allow relatively safe fusion
takeoffs and landings, but this strikes me as military installation
equipment. But most space ports would not need this.
So the picture of a take off that I have is: initial liftoff on CG and
thrusters, and once you are in the air at a safe or regulation altitude you
punch on the fusion drive at low and disappear as far as the ground is
concerned. Once you clear orbit, you bring the drive up to maximum.
Gee kind of sounds like how the space ships in SW took off; don't hold it
against me! ;-}
Now, this is not to say that you *couldn't* use a fusion drive as a weapon.
And I imagine that you could. I don't see how you can avoid this without
drastic handwaving. Any Tool can be a Weapon. But some Weapons don't make
very good Tools.
In any case, the fusion drive is designed for thrust, while the FGMP/PGMP
are designed to inflict damage. I imagine it's possible that fusion
drives are much less efficient as inflicting damage then the FGMP/PGMP; on
the other hand, drives are *big*. I think it's likely that the drive emits
proportionally much more KE and radiation then matter then the PGMP.
I imagine that there is some minimum range below which using the drive as a
weapon is hazardous to the attacker, and some maximum range where it's
relatively harmless. I'll leave it to others to argue about the range.
If fusion drives *are* going to be used as weapons, will they become the
major weapons like spinal mount weapons in good-old-fashioned-traveller?
Very Niven-like, ships with combination drive/spinal mounts.
Well that's how I see it.
C: The Virus: computers keep programs and data seperate.
Not on your life. Never have, and never will. I transfer data between
systems, stuff it in data files, and them compile and execute the programs
in those very same files all the time. What about system control data
files?
All that a virus requires is access to the computer in *some* form, even as
data. The Virus gets stuffed into a file. Then the Virus figures out some
method of fooling the computer into thinking that that file needs to be
compiled or included into it's programming or control data structures.
Non trivial, but this will always be the case. The virus will always have
the possibility of pretending to be some priviledged user at the least.
I *don't* believe any of this 'the virus changes/is the hardware chips'
crap. However, as someone pointed out, most everything is EEPROMS, PROMS,
PALS, PLAS, and loaded software already anyway. I don't think that it's as
simple as 'finding a good backup' though. The virus is likely to tell your
operator to mount your old backup tapes to rewrite them, or hang around for
a few years untill it is on all your backups.
What we should see, is not computers being impossible, but much more dumb,
and hardwired computers, and less programmable and adaptable computers,
more write once storage.
Enough for now...
Jim Baranski